Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id LAA27900 for ietf-xml-mime-bks; Wed, 28 Apr 1999 11:30:02 -0700 (PDT) Received: from hesketh.net (wasabi-eth0-1.hesketh.net [216.27.10.31]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id LAA27896 for ; Wed, 28 Apr 1999 11:30:01 -0700 (PDT) Received: from simon (slip129-37-221-54.ny.us.ibm.net [129.37.221.54]) by hesketh.net (8.8.8/8.8.8) with SMTP id OAA10940 for ; Wed, 28 Apr 1999 14:31:37 -0400 Message-Id: <4.0.1.19990428142914.00fac100@207.211.141.31> X-Sender: simonstl@207.211.141.31 X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0.1 Date: Wed, 28 Apr 1999 14:34:48 -0400 To: ietf-xml-mime@imc.org From: "Simon St.Laurent" Subject: Fwd: RE: Transformation + FOs makes abuse easy Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: It's a little ways out from the discussions that have dominated this list, but I thought it might raise some interesting issues. (text/xfo would be for documents using the XSL Formatting Objects vocabulary.) I'm violently opposed to these transmissions, but the use of MIME as a supporting infrastructure component seems likely, so I thought I'd put it on the radar screen. >From: Miles Sabin >To: "'xsl-list@mulberrytech.com'" >Cc: "'simonstl@simonstl.com'" >Subject: RE: Transformation + FOs makes abuse easy >Date: Wed, 28 Apr 1999 18:41:28 +0100 > >Simon St.Laurent wrote, >> As a result, the 'meaningful Web' project that was the >> driving force (at least in public) for the creation of >> XML is at risk. Server-side transformation from >> semantically rich private vocabularies to presentation- >> oriented public vocabularies may leave the Web exactly >> where it was before - interesting to read, but not very >> useful. > >Silly question, but (modulo the invention of a few new >mime types), wouldn't the distinction between, > > Accept: text/xml, text/xsl > >and, > > Accept: text/xfo > >resolve this issue? Ie. if you're happy to recieve a >presentation-oriented server-side processed document you >use the latter. If you want it undigested, you use the >former. > >Cheers, > > >Miles > >-- >Miles Sabin Cromwell Media >Internet Systems Architect 5/6 Glenthorne Mews >+44 (0)181 410 2230 London, W6 0LJ >msabin@cromwellmedia.co.uk England > Simon St.Laurent XML: A Primer Sharing Bandwidth / Cookies http://www.simonstl.com Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id UAA17107 for ietf-xml-mime-bks; Sun, 18 Apr 1999 20:15:49 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id UAA17103 for ; Sun, 18 Apr 1999 20:15:48 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <52665(4)>; Sun, 18 Apr 1999 20:16:29 PDT Received: from copper.parc.xerox.com ([13.1.102.170]) by thelma.parc.xerox.com with SMTP id <99519>; Sun, 18 Apr 1999 20:16:18 PDT From: "Larry Masinter" To: "MURATA Makoto" , Subject: RE: Parameters for top-level XML media types? Date: Sun, 18 Apr 1999 20:16:11 PDT Message-ID: <000d01be8a12$f9b53780$aa66010d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 Importance: Normal In-Reply-To: <199904161104.AA00313@archlute.apsdc.ksp.fujixerox.co.jp> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > - the version of XML, Not any more than Postscript 1 and Postscript 2 having separate versions. > - the version of Unicode, Not for any other text type, why for XML? > - how the Private Use Area (PUA) of Unicode is used > [Rick Jelliffe wrote: "This also could have bearing on the PUA > (private use area) character problem, and the problem of corporate > character sets (e.g. Hong Kong's GCCS)."] Using Private Use Area in Unicode is tantamount to using a private charset. Suggestion: a) eliminate text/xml b) eliminate 'charset' parameter from application/xml The charset is self-identifying. If there is a PUA in use, then it must be declared in the head of the XML body. Having PUAs in your charset is like having a private use font. > - which conversion table (Note: for a given CCS, more than one conversion > table may exist), > - which schema language is used (DTD or the upcoming schema language > from W3C), > - which stylesheet (XSL, CSS, DSSSL, etc.) is used, and > - other issues mentioned in my mail "List of issues". > > Does anybody think that some of them are good enough reasons for introducing > top-level XML media types? (I am just asking.) These are good reasons for making sure that this information is self-identified in the head of the XML body. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA13270 for ietf-xml-mime-bks; Fri, 16 Apr 1999 09:13:13 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id JAA13266 for ; Fri, 16 Apr 1999 09:13:12 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <54580(1)>; Fri, 16 Apr 1999 09:13:46 PDT Received: from copper.parc.xerox.com ([13.0.208.21]) by thelma.parc.xerox.com with SMTP id <98911>; Fri, 16 Apr 1999 09:13:39 PDT From: "Larry Masinter" To: "Larry Masinter" , "MURATA Makoto" , Subject: RE: Five proposed solutions Date: Fri, 16 Apr 1999 09:13:35 PDT Message-ID: <001501be8824$14432ee0$15d0000d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-Reply-To: <001201be8823$885ece20$15d0000d@copper.parc.xerox.com> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > So perhaps the calandaring applications have components > that use MIME but aren't intended to be processed by a general > MIME processor, and so separate MIME types are needed. er: So perhaps the calendaring applications have components that use XML but aren't intended to be processed by a general XML processor, so separate MIME types are needed. Sorry, Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA12739 for ietf-xml-mime-bks; Fri, 16 Apr 1999 09:09:27 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id JAA12734 for ; Fri, 16 Apr 1999 09:09:25 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <54553(2)>; Fri, 16 Apr 1999 09:09:55 PDT Received: from copper.parc.xerox.com ([13.0.208.21]) by thelma.parc.xerox.com with SMTP id <98906>; Fri, 16 Apr 1999 09:09:45 PDT From: "Larry Masinter" To: "MURATA Makoto" , Subject: RE: Five proposed solutions Date: Fri, 16 Apr 1999 09:09:40 PDT Message-ID: <001201be8823$885ece20$15d0000d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-Reply-To: <199904160913.AA00309@archlute.apsdc.ksp.fujixerox.co.jp> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > Q1. Do you propose to revise RFC 2048 and discourage media types > that are built on top of XML? Certainly not. People can build media types "that are built on top of XML", in the same way that XML is a media type that is built on top of "text/plain". XML inherits many of the characteristics of text/plain, but it isn't text/plain, because that's not how it is intended to be processed. text/plain can be processed with a generic text processor, but you can't tell the difference between my autoexec.bat and a web page. > Q2. Do you propose to revise RFC 2376 and discourage such > media types? I think that the revision of RFC 2376 (necessary anyway) will need to give some guidelines. For the most part, the external representations of components of XML don't need any MIME designation at all, because in order to process them, they have to be supplied in some context or wrapped in some kind of packaging or container that doesn't need to use MIME anyway. (That is, the MIME label might as well be text/plain or application/octet-stream). The only cases where you need a MIME label at all is when the body is being sent as a message body; i.e., in a context where you might be sending almost anything at all. MIME is _not_ the only way of labelling data in Internet protocols. Even in those cases, applications where the type of message body can be distinguished by the DOCTYPE within the XML body need not define a separate MIME type. In some cases, where the body isn't intended to be processed by a general XML processor, but a separately coded processor for some subset of XML that was designed for the application, or where the bodies don't contain sufficient declarations internally to distinguish them from other body types, it might be necessary to register a separate MIME type. So perhaps the calandaring applications have components that use MIME but aren't intended to be processed by a general MIME processor, and so separate MIME types are needed. It would be useful to note that the generic text/xml or application/xml designations are only appropriate for those bodies that contain a DOCTYPE (or whatever new typing mechanism you're going to add.) I.e., "XML bodies that are intended to be used in Internet protocols should always contain a DOCTYPE." You might even want to restrict the use so that the initial segment is easy to parse without invoking a general XML parser. Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id EAA02229 for ietf-xml-mime-bks; Fri, 16 Apr 1999 04:04:58 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id EAA02225 for ; Fri, 16 Apr 1999 04:04:57 -0700 (PDT) Received: by mx.fujixerox.co.jp; id UAA09839; Fri, 16 Apr 1999 20:05:29 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma009802; Fri, 16 Apr 99 20:05:01 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id UAA23716 for ; Fri, 16 Apr 1999 20:02:57 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id UAA16036 for ; Fri, 16 Apr 1999 20:05:00 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id UAA01294 for ; Fri, 16 Apr 1999 20:03:00 +0900 Message-Id: <199904161104.AA00313@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Fri, 16 Apr 1999 20:04:57 +0900 To: ietf-xml-mime@imc.org Subject: Parameters for top-level XML media types? MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: We have agreed on two points about fallback. > 3. Fallback to general-purpose XML applications is not useful. > > 4. Document-like XML documents can be handled by general-purpose > XML viewers Other than fallback, are there any reasons for introducing top-level XML media types? One possible reason is that all subtypes can share parameters of the top-level media types. Possibilities for such parameters are as below: - the version of XML, - the version of Unicode, - how the Private Use Area (PUA) of Unicode is used [Rick Jelliffe wrote: "This also could have bearing on the PUA (private use area) character problem, and the problem of corporate character sets (e.g. Hong Kong's GCCS)."] - which conversion table (Note: for a given CCS, more than one conversion table may exist), - which schema language is used (DTD or the upcoming schema language from W3C), - which stylesheet (XSL, CSS, DSSSL, etc.) is used, and - other issues mentioned in my mail "List of issues". Does anybody think that some of them are good enough reasons for introducing top-level XML media types? (I am just asking.) Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id CAA27556 for ietf-xml-mime-bks; Fri, 16 Apr 1999 02:14:09 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id CAA27552 for ; Fri, 16 Apr 1999 02:14:07 -0700 (PDT) Received: by mx.fujixerox.co.jp; id SAA12629; Fri, 16 Apr 1999 18:14:39 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma012435; Fri, 16 Apr 99 18:13:58 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id SAA28076 for ; Fri, 16 Apr 1999 18:11:53 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id SAA12861 for ; Fri, 16 Apr 1999 18:13:56 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id SAA29469 for ; Fri, 16 Apr 1999 18:11:56 +0900 Message-Id: <199904160913.AA00309@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Fri, 16 Apr 1999 18:13:53 +0900 To: Subject: Re: Five proposed solutions In-Reply-To: <001701be8755$634ccca0$15d0000d@copper.parc.xerox.com> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: > I'm afraid you've let your personal viewpoint color your summary > of the issues. You said: > > "Solution 5 has not received any support." > > and then gave quotes which, for the most part, don't really support > that summary. I tried not to mix my personal viewpoint. Even if I had failed to do so, that was never intended. Anyway, my mail and your note (and probably your response to my questions below) collectively provide a "summary". I have two questions for clarification. Larry Masinter wrote: > I'd like to recommend > that applications use text/xml or application/xml, unless they > have a strong need to do something else, and note that in most > cases, there isn't a strong need, since the actual nature of > the data can be determined by looking inside the XML itself. Q1. Do you propose to revise RFC 2048 and discourage media types that are built on top of XML? Q2. Do you propose to revise RFC 2376 and discourage such media types? Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id IAA23408 for ietf-xml-mime-bks; Thu, 15 Apr 1999 08:34:07 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id IAA23404 for ; Thu, 15 Apr 1999 08:34:06 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <51855(3)>; Thu, 15 Apr 1999 08:34:26 PDT Received: from copper.parc.xerox.com ([13.0.208.21]) by thelma.parc.xerox.com with SMTP id <98484>; Thu, 15 Apr 1999 08:34:13 PDT From: "Larry Masinter" To: "MURATA Makoto" , Subject: RE: Five proposed solutions Date: Thu, 15 Apr 1999 08:34:02 PDT Message-ID: <001701be8755$634ccca0$15d0000d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-Reply-To: <199904151442.AA00303@archlute.apsdc.ksp.fujixerox.co.jp> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Importance: Normal Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I'm afraid you've let your personal viewpoint color your summary of the issues. You said: "Solution 5 has not received any support." and then gave quotes which, for the most part, don't really support that summary. > The others disagree for basically two reasons. The first reason is > that we should not prevent developers from developing new media types > only because they use XML. "Solution 5" doesn't prevent developers from developing new media types. "Solution 5" just asks developers to code new media types using existing media type labels. They are free to develop new kinds of media. "Solution 5" doesn't prevent new developments. It just says that those new developments are labeled as "text/xml" or "application/xml". > "If the answer to this is "no, we don't want to try and > control the development, direction, and use of XML" then your > question is basically out of scope. People will design > whatever they want and register whatever they want. The > resulting mixtures and granularity will be whatever developers > decide is appropriate." (Ned) I thought Ned's position was actually agreeing with Solution 5. I don't think that it's a matter of whether we "want" to control these things, but whether it's practical. I'd like to recommend that applications use text/xml or application/xml, unless they have a strong need to do something else, and note that in most cases, there isn't a strong need, since the actual nature of the data can be determined by looking inside the XML itself. > "Not just developers; increasingly, vertical markets. An XML > namespace for real-estate listings, for example. One for > dental records. So forth." (Chris) I don't see that Chris is arguing against using text/xml or application/xml as the MIME label for external representations for XML bodies that use vertical market namespaces. > "This is the position of W3C; certain building blocks are made > available (foundational blocks such as XML itself, XLink, > XPointer, namespaces, etc; useful common things like > styleshets, SVG for images, RDF for metadata which can be used > or not as appropriate) but the way in which people combine > these building blocks is up to them, and the element names > that they use (when not using a building block that defines > names for them, like XHTML and SVG do) is entirely their own > affair." (Chris) This doesn't argue one way or another against "solution 5". > The second reason is the burden of parsing. The arguments from Chris and Frank are all about IMAP. But the problem isn't a general one for "a mail protocol like IMAP", it is "IMAP" that has the problem. An IMAP server has parsed the MIME bodies of the messages in the mail store, in any case. It's separated out multipart bodies, parsed the mail headers into names and values, dealt with various encoding issues. The only problem is that IMAP contains inconsistent access to parsing and query facilities. But this is just a weakness of IMAP. If you were using, say, WebDAV, to access your mailbox, then the DTD of the XML body of your mail could as easily be a property of the message body. > "Certainly with a mail protocol like IMAP you can look through > your inbox for entries based on values of the MIME header > fields. The example mentioned was a "mail-enabled" > application. For this application, the implementors on the > IETF CALSCH WG felt very much that the MIME header field > parameters were of importance." (Frank) > > "Yes; especially in the case of IMAP where the initial > selection of bodis is done on the server and likely ones are > sent to the client for the calendar program to further > process." (Chris) > "But it [specialized media types] sure cuts down the class of > data to be further processed. Instead of searching through the > entire mailbox/the entire server, just search in the > text/calendar resources." (Frank) > > "The overhead of having to open up every XML document to find > out what document type it is is not practical. As in the case > of email, all I should have to do is ask for a particular type > of object from the store and get it." (Frank) > > "There needs to be some balance between an infinite number of > media types/subtypes for each transaction type and a smaller, > managable number of media types for each logical application > object type. As Ned has pointed out, this example and other > show that leaving "hooks" on the outside of the object wrapper > is very useful in providing a scalable, practical Internet > solution using XML." (Frank) > > "The thing to avoid, though, it to havce to parse the document > once to find out what sort of thing it is, dispatch it > somewhere else, and then have that "somewhere else" start > parsing again from scratch. If that can be avoided by better > labelling up front, that is a win." (Chris) In general, we have to do this anyway: we parse the MIME to separate out the multipart bodies, and then reparse the bodies when we do the dispatch. If there's a generic XML dispatch engine in your operating system, then perhaps it can pass on parsed-XML instead of raw-XML, though, which would save some of the extra processing. The dispatched XML media handlers would operate with DOM rather than by reparsing, even if one of them was a DOM-toothbrush-interpreter and another was a DOM-apartment-for-rent processor. Larry -- http://www.parc.xerox.com/masinter Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id HAA20812 for ietf-xml-mime-bks; Thu, 15 Apr 1999 07:42:47 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id HAA20804 for ; Thu, 15 Apr 1999 07:42:45 -0700 (PDT) Received: by mx.fujixerox.co.jp; id XAA24626; Thu, 15 Apr 1999 23:42:48 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma024591; Thu, 15 Apr 99 23:42:23 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id XAA16120 for ; Thu, 15 Apr 1999 23:40:19 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id XAA13655 for ; Thu, 15 Apr 1999 23:42:22 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id XAA14703 for ; Thu, 15 Apr 1999 23:40:14 +0900 Message-Id: <199904151442.AA00303@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Thu, 15 Apr 1999 23:42:04 +0900 To: ietf-xml-mime@imc.org Subject: Five proposed solutions MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: 1. Summary My first mail to this mailing list lists four possible solutions for dispatching (and content negotiation). Solution 1. Specialized media types (possibly with some parameters) Solution 2: New top-level media type xml and its subtypes Solution 3: A new parameter "externalid" for text/xml and application/xml Solution 4: Yet another parameter "optinfo" or "ADD-PARAM" on top of solution 3 Larry added another. Solution 5: The handler of the XML media types examines the XML MIME entity and then dispatches to one of several possible media type handlers. So far, solution 1 has found some strong support. Solution 2 has neither strong opposition nor strong support, but has been questioned. Solution 3 and 4 do not work. Solution 5 has not received any support. 2. Solution 1 Solution 1 has found some strong support. "I tend to lean towards "every application gets a new media type." (PaulH) "In case it isn't obvious by now, so do I." (Ned) "My quick and dirty way of thinking of this is that the media type/subtype should to be sufficient to get you the right application, but the parameters then can tell that application what to do, or when to do it, or various other sorts of things that for whatever reason are best not stored in or derived from the actual content." (Ned) One concern is the burden of registration, but "Registration of media subtypes is easy." (Agreement 1 in "What we have agreed on"). Furthermore, a specialized media type may require parameters specific to that media type. "However, in the general problem space surrounding these sorts of applications, I see value in using parameters." (Ned) "However, just having a "calendar" media type won't cut it. The CUA needs to be able to search the MIME entity bucket for particular types of "calendar" media types." (Frank) 3. Solution 2 We have not yet found good reasons fot a top-level media type for xml. Fallback is not a good reason, since "Fallback to general-purpose XML applications is not useful." (Agreement 3 in "What we have agreed on"). Here are some other weak reasons. "However, if the answer [My note: the more general question of whether there is to be an attempt to "design" the XML usage space, and if there is, whether such an attempt has any chance of succeeding.] to this is "yes", then the task at hand becomes one of coming up with an appropriate set of rules that people think will actually do the job and will be followed. And in such a world a top-level XML type might have some value, if only as a place to attach the ruleset." (Ned) "The only value I would see is if the fallbacks and other behaviours of the text/* tree were seen to be unavoidable and made the use of XML too fragile there. XML element names and element content can use all sorts of Unicode characters." (Chris) "We can also lift the line termination rule of the top-level media type "text"." (Murata) [Note: There are some possible reasons, which I will mention my personal mail.] However, it might make sense to introduce a top-level media type for document-like XML, since "Document-like XML documents can be handled by general-purpose XML viewers" (Agreement 4 in "What we have agreed on"). 4. Solution 3 and 4 Solution 3 and 4 do not work, since "Dispatch based on parameters are not widely supported" (Agreement 2). "I'm afraid you've missed the biggest problem with this approach -- one that makes it almost a complete nonstarter: The lack of ability to dispatch on parameters in most applications that support MIME." (Ned) 5. Solution 5 Larry advocates this solution. He points out that MIME headers cannot entirely solve the problem of dispatching and negotiation. "In general, you cannot solve the problem of "dispatch to the appropriate handler" by modifying MIME, since finding the appropriate handler is platform and installation dependent." (Larry) "And adding more MIME types for each kind of combination of XML seems like a recipe for disaster. If we have html, xhtml, html-netscape, html-microsoft, html-optimized-for-msie-on-windows-nt50, each with slightly different definitions, would they get separate MIME types?" (Larry) "... specialized media types should be introduced with caution, since a world in which every kind of document has its own media types is one in which there is little interoperability." (Larry) "Neither adding parameters to text/calendar nor inventing new MIME subtypes for text/calendar-request text/calendar-response etc. will help implement the query capabilities that you need. ... Since it doesn't work, stop trying. You need some other kind of query protocol than keying off content-type." (Larry) "Someone has to parse them. Certainly if a search engine can parse web pages to find the words and their lexical equivalences, an event search engine can parse the XML documents and index them in the multiple ways that searching the calendar-event database needs to be searched." (Larry) "Purchase orders that are applicable to the particular division, purchase orders that haven't already been processed, purchase orders that are assigned to a particular account rep, etc. These are all database search problems, not type-indexing problems." (Larry) "You might also want to scan your email for "event invitations from my boss", and you can't solve that problem with specialized MIME media types. So the question is: are there any realistic cases where having a "text/calendar" distinction in the email header actually helps substantially in deciding which email bodies to retrieve?" (Larry) The others disagree for basically two reasons. The first reason is that we should not prevent developers from developing new media types only because they use XML. "If the answer to this is "no, we don't want to try and control the development, direction, and use of XML" then your question is basically out of scope. People will design whatever they want and register whatever they want. The resulting mixtures and granularity will be whatever developers decide is appropriate." (Ned) "Not just developers; increasingly, vertical markets. An XML namespace for real-estate listings, for example. One for dental records. So forth." (Chris) "This is the position of W3C; certain building blocks are made available (foundational blocks such as XML itself, XLink, XPointer, namespaces, etc; useful common things like styleshets, SVG for images, RDF for metadata which can be used or not as appropriate) but the way in which people combine these building blocks is up to them, and the element names that they use (when not using a building block that defines names for them, like XHTML and SVG do) is entirely their own affair." (Chris) The second reason is the burden of parsing. "Certainly with a mail protocol like IMAP you can look through your inbox for entries based on values of the MIME header fields. The example mentioned was a "mail-enabled" application. For this application, the implementors on the IETF CALSCH WG felt very much that the MIME header field parameters were of importance." (Frank) "Yes; especially in the case of IMAP where the initial selection of bodis is done on the server and likely ones are sent to the client for the calendar program to further process." (Chris) "But it [specialized media types] sure cuts down the class of data to be further processed. Instead of searching through the entire mailbox/the entire server, just search in the text/calendar resources." (Frank) "The overhead of having to open up every XML document to find out what document type it is is not practical. As in the case of email, all I should have to do is ask for a particular type of object from the store and get it." (Frank) "There needs to be some balance between an infinite number of media types/subtypes for each transaction type and a smaller, managable number of media types for each logical application object type. As Ned has pointed out, this example and other show that leaving "hooks" on the outside of the object wrapper is very useful in providing a scalable, practical Internet solution using XML." (Frank) "The thing to avoid, though, it to havce to parse the document once to find out what sort of thing it is, dispatch it somewhere else, and then have that "somewhere else" start parsing again from scratch. If that can be avoided by better labelling up front, that is a win." (Chris) Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id EAA00328 for ietf-xml-mime-bks; Wed, 14 Apr 1999 04:10:12 -0700 (PDT) Received: from gate.sinica.edu.tw (gate.sinica.edu.tw [140.109.4.130]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id EAA00324 for ; Wed, 14 Apr 1999 04:10:10 -0700 (PDT) Received: from pnc01.sinica.edu.tw ([140.109.6.221]) by gate.sinica.edu.tw (8.9.3/8.9.3) with SMTP id TAA19338; Wed, 14 Apr 1999 19:10:22 +0800 (CST) Message-ID: <002701be8666$22c6e980$dd066d8c@sinica.edu.tw> From: "Rick Jelliffe" To: "Martin J. Duerst" Cc: References: <199904130925.SAA23471@sh.w3.mag.keio.ac.jp> <199904140628.PAA02332@sh.w3.mag.keio.ac.jp> Subject: Re: Positions on "List of issues" Date: Wed, 14 Apr 1999 19:01:23 +0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: From: Martin J. Duerst >But in the general case, the idea is really that you > say what it is, and leave the rest of the choice to the user and it's > environment. "What it is" is a judgement based on the provider's expectations about how the document will act at the recipient. I don't think many people will just stick XML on the net without some intended application. But people feel that text/xml does not allow them to express "what it is"; in particular, I think people want to run a Java program on the XML document without having to load an initial HTML document first. If that is, in fact, the major need, is it something that text/xml should address? Personally, I don't think so. Rick Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA19715 for ietf-xml-mime-bks; Tue, 13 Apr 1999 23:28:58 -0700 (PDT) Received: from sh.w3.mag.keio.ac.jp (sh.w3.mag.keio.ac.jp [133.27.194.41]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA19700 for ; Tue, 13 Apr 1999 23:28:35 -0700 (PDT) Received: from enoshima (pv24.mag.keio.ac.jp [133.27.195.124]) by sh.w3.mag.keio.ac.jp (8.9.0/3.6W-W3C/Keio) with SMTP id PAA02332; Wed, 14 Apr 1999 15:28:31 +0900 (JST) Message-Id: <199904140628.PAA02332@sh.w3.mag.keio.ac.jp> X-Sender: duerst@sh.w3.mag.keio.ac.jp X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3-J (32) Date: Wed, 14 Apr 1999 15:00:31 +0900 To: "Rick Jelliffe" From: "Martin J. Duerst" Subject: Re: Positions on "List of issues" Cc: In-Reply-To: <001a01be85a5$7308b0c0$dd066d8c@sinica.edu.tw> References: <199904130925.SAA23471@sh.w3.mag.keio.ac.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 20:02 99/04/13 +0800, Rick Jelliffe wrote: > My 2 cents worth: > > > Issue 1: Proposals for additional parameters in the past > > I agree with Tim Bray that it is inappropriate to give the DTD in a > parameter: in particular, because XML content models are basically glorified > assert() statements. DOCTYPE declarations are fine and appropriate where > they are. > In particular, I think we are missing a key distinction that the MIME > content-type is not so much the "type" of a resource, but the type of a > particular *publication* of a resource. Well, if it's to distinguish the PS version of a document from the pdf version and from the HTML version, then you are certainly right. And it should also be possible to serve something as text/plain if one really wants. But in the general case, the idea is really that you say what it is, and leave the rest of the choice to the user and it's environment. Cases where this doesn't work are implementation problems, not proofs of concept. > Furthermore, let me bring up another problem with parameters: the parameters > have to be sourced from somewhere: everytime we have to duplicate > information from inside an XML document into a header, we create the chance > for a mismatch. Yes indeed. [I might come back to this point in another discussion :-] The main distinction is: What do you want to be able to do without having to look inside the resource. On many systems, having to look inside or not is a big distinction in practical terms. > > RFC 2376 should be revised when charsets for UTF-16 are registered. > > Yes. And XML appendix F should be revised simultaneously, so that the > specifications are kept in sync. Good point. > > Issue 4: Characters .vs. bytes > > > An XML MIME entity is a sequence of characters as opposed to a > > sequence of bytes. RFC 2376 is not really clear about this. > > This is the old question. When we discussed it before, didn't we say that: > * a text/xml entity is a sequence of characters > * an application/xml entity is a sequence of bytes? > > I hope an application/* is not a sequence of characters. Definitely not. In both cases, there are two levels, the character level and the byte level. In both cases, XML is defined in terms of characters, and not bytes. Therefore, in both cases, an XML document is a sequence of characters. In both cases, when sent as a MIME entity, it has to be sent as a sequence of bytes. You are right that in the case of application/xml, the chance that the bytes don't change is higher than in the case of text/xml, but it is pretty high in both cases anyway. > > Issue 6: Ambiguity of CCS conversion > > > If this is the case, it might make sense to introduce a parameter > > "map" to precisely specify which mapping should be used. > > This also could have bearing on the PUA (private use area) character > problem, and the problem of corporate character sets (e.g. Hong Kong's > GCCS). Adding parameters will just increase the mess with current charsets. It will send the message "it's okay to change a charset slightly, just add a parameter". This is definitely not what we need! Regards, Martin. #-#-# Martin J. Du"rst, World Wide Web Consortium #-#-# mailto:duerst@w3.org http://www.w3.org Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id LAA19883 for ietf-xml-mime-bks; Tue, 13 Apr 1999 11:31:57 -0700 (PDT) Received: from gate.sinica.edu.tw (gate.sinica.edu.tw [140.109.4.130]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id LAA19879 for ; Tue, 13 Apr 1999 11:31:55 -0700 (PDT) Received: (from ricko@localhost) by gate.sinica.edu.tw (8.9.3/8.9.3) id CAA01061; Wed, 14 Apr 1999 02:32:04 +0800 (CST) Date: Wed, 14 Apr 1999 02:32:03 +0800 (CST) From: Rick Jelliffe To: Paul Langer cc: ietf-xml-mime@imc.org Subject: Re: Positions on "List of issues" In-Reply-To: <9904131715.AA10299@server3.software-ag.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: On Tue, 13 Apr 1999, Paul Langer wrote: > Rick Jelliffe wrote > (http://www.imc.org/ietf-xml-mime/mail-archive/msg00064.html): > > In particular, I think we are missing a key distinction that the MIME > > content-type is not so much the "type" of a resource, but the type of a > > particular *publication* of a resource. > > I disagree with this definiton of the semantics of "MIME content-type". > XML is portable data; the particular use of this data should not be > specified by the "publisher". The user should be able to detect the > data type and then select an application that he/she likes. How can a > "publisher" know, what applications are available at the user's site? My point is not that a "publication" selects an application, but that it is metadata which is expected to select a class of handler: we expect a MIME content-type of application/xml will select a different class of handler to text/plain. Otherwise, all XML would be text/plain and we wouldn't need this mail list. If you want an example, the DTDs on my site at http://www.ascc.net/xml/ are typically published both as .dtd (text/xml) and .txt (text/plain). This is because I don't know which class of handler the user has: in the case of IE5, the DTD will cause a WF error, and it the user cannot View Source (if they know how) to view the whole DTD, because the file transmission is aborted. Providing this kind of multiple content-type doesnt require any additional MIME parameters, I can do it at on the file system using links. Rick Jelliffe Academia Sinica Computing Center Tapei, Taiwan Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id KAA17325 for ietf-xml-mime-bks; Tue, 13 Apr 1999 10:11:29 -0700 (PDT) Received: from server1.software-ag.de (server1.software-ag.de [193.26.194.2]) by mail.proper.com (8.8.8/8.8.5) with SMTP id KAA17319 for ; Tue, 13 Apr 1999 10:11:26 -0700 (PDT) Received: from server3.software-ag.de by server1.software-ag.de; (5.65v3.2/1.1.8.2/21Dec95-0433PM) id AA10561; Tue, 13 Apr 1999 19:15:35 +0200 Received: from pcpl.software-ag.de by server3.software-ag.de; (5.65v3.2/1.1.8.2/21Dec95-0542PM) id AA10299; Tue, 13 Apr 1999 19:15:34 +0200 Date: Tue, 13 Apr 1999 19:15:34 +0200 Message-Id: <9904131715.AA10299@server3.software-ag.de> From: Paul Langer To: ricko@gate.sinica.edu.tw Cc: ietf-xml-mime@imc.org In-Reply-To: <001a01be85a5$7308b0c0$dd066d8c@sinica.edu.tw> (ricko@gate.sinica.edu.tw) Subject: Re: Positions on "List of issues" References: <199904130925.SAA23471@sh.w3.mag.keio.ac.jp> <001a01be85a5$7308b0c0$dd066d8c@sinica.edu.tw> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Rick Jelliffe wrote (http://www.imc.org/ietf-xml-mime/mail-archive/msg00064.html): > In particular, I think we are missing a key distinction that the MIME > content-type is not so much the "type" of a resource, but the type of a > particular *publication* of a resource. I disagree with this definiton of the semantics of "MIME content-type". As far as I know, the MIME mechanism is the only mechanism for data typing that is available today on the Internet. The HTTP/1.1 spec (http://www.w3.org/Protocols/HTTP/1.1/draft-ietf-http-v11-spec-rev-06.txt) says: "3.7 Media Types HTTP uses Internet Media Types [17] in the Content-Type (section 14.17) and Accept (section 14.1) header fields in order to provide open and extensible data typing and type negotiation." XML is portable data; the particular use of this data should not be specified by the "publisher". The user should be able to detect the data type and then select an application that he/she likes. How can a "publisher" know, what applications are available at the user's site? All the best, Paul ----------------------------------------------------------- Paul Langer E-mail pl@softwareag.com Software AG Tel. +49-6151-92-1912 Uhlandstr. 12 Fax +49-6151-92-1613 D-64297 Darmstadt Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id HAA11991 for ietf-xml-mime-bks; Tue, 13 Apr 1999 07:32:53 -0700 (PDT) Received: from hesketh.net (wasabi-eth0-1.hesketh.net [216.27.10.31]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id HAA11985 for ; Tue, 13 Apr 1999 07:32:52 -0700 (PDT) Received: from simon (slip129-37-221-142.ny.us.ibm.net [129.37.221.142]) by hesketh.net (8.8.8/8.8.8) with SMTP id KAA10774; Tue, 13 Apr 1999 10:33:02 -0400 Message-Id: <199904131433.KAA10774@hesketh.net> X-Sender: simonstl@207.211.141.31 X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0.1 Date: Tue, 13 Apr 1999 10:36:18 -0400 To: , From: "Simon St.Laurent" Subject: Catalogs and MIME types In-Reply-To: <003601be8563$9dae87b0$0100007f@eps.inso.com> References: <3.0.32.19990407094512.00cee720@pop.intergate.bc.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 11:25 PM 4/12/99 -0400, Gavin Thomas Nicol wrote: >I should note that both Simon St. Laurent and Chris Lilley have been making >noise about such "catalogs" recently as well. And then later: >> Rather than extending the MIME headers with lots of >> parameter, perhaps just the URI of a single resource like that would allow >greater >> extensibility. > >Yes, I think this is absolutely the right way to go. The only thing I would >add is that packaging itself has many facets: the "catalog" (drlove, XPDL, >etc.) >definition, packaging in MIME multipart/*, resource name aliasing, push vs. >pull, >mixed mode push/pull, etc. that all need to be considered. XPDL (http://purl.oclc.org/NET/xpdl) is exactly about this packaging (and I really should talk with Rick about his drlove project to figure out if we have much in common.) After a number of rounds on XML-Dev complaining about the imprecision of the methods currently available for identifying XML document types (including MIME), I figured it was time to go ahead and write up a proposal for describing such types. At this point, I think I'm leaning toward leaving the MIME type application/xml for documents (and creating something more descriptive for DTDs) and using a different mechanism to connect the descriptions to the document. (The XPDL draft currently has five possibilities, and I'm pondering a sixth.) Rick's point that a single XML document may be a chameleon of MIME types, capable of being presented as text/x-myType, application/xml, possibly text/xml and text/plain, and potentially even more, seems very striking. We've moved beyond "one document - one type" and dealing with that will be difficult. I think I'd rather let MIME identify a basic type - application/xml - and develop another mechanism for detail beyond that. XML documents share some key features as far as transfer over networks, which to me at least is what MIME is best for helping with. Simon St.Laurent XML: A Primer Sharing Bandwidth / Cookies http://www.simonstl.com Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id GAA10794 for ietf-xml-mime-bks; Tue, 13 Apr 1999 06:40:09 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id GAA10788 for ; Tue, 13 Apr 1999 06:40:08 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id JAA12777; Tue, 13 Apr 1999 09:40:16 -0400 Message-ID: <37134835.A4152774@w3.org> Date: Tue, 13 Apr 1999 15:35:49 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: MURATA Makoto CC: ietf-xml-mime@imc.org Subject: Re: DTD media type? References: <199904131033.AA00281@archlute.apsdc.ksp.fujixerox.co.jp> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: MURATA Makoto wrote: > > Martin J. Duerst wrote: > > Is there somewhere a web page where all these terms > > are defined and explained with simple examples, or something similar? > Here is an imprecise-but-not-totally-inappropriate analogy. > > XML documents are source programs. [...] This is a strikingly good analogy; I wish I had read your mail before giving my tutorial today. Lots of people are familiar with programming; it hadn't occurred to me to > The BNF for XML documents and that for external DTD subsets are quite > different. On the other hand, some external parsed entities are > legal XML documents, and some external parameter entities are legal > external DTD subsets. > > Viewers for XML documents and viewers for external DTD subsets are > quite different. This is a good summary. It shows that, for example, a generic XML parser and router, as has been discussed on this list, would bot be able to deal with external DTD subsets. Since the parser is different (or rather, since the start token is different) then using a parameter would not seem wise. Rather, a different MIME type (for example, text/xml-xdtd ) would seem a better choice. Or application/xml-xdtd if we decide that text/* is unusable for XML. We currently serve DTDs as text/plain on the W3C site; it would be better to use a more descriptive type. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id GAA10180 for ietf-xml-mime-bks; Tue, 13 Apr 1999 06:12:59 -0700 (PDT) Received: from tribble.eps.inso.com (tribble.eps.inso.com [198.112.118.8]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id GAA10176 for ; Tue, 13 Apr 1999 06:12:57 -0700 (PDT) Received: from endymion (modem_c [199.93.212.245]) by tribble.eps.inso.com (8.9.1/8.9.1) with SMTP id JAA03251 for ; Tue, 13 Apr 1999 09:09:28 -0400 (EDT) Reply-To: From: "Gavin Thomas Nicol" To: Subject: RE: Positions on "List of issues" Date: Tue, 13 Apr 1999 09:16:16 -0400 Message-ID: <004f01be85af$d0708a80$0100007f@eps.inso.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2212 (4.71.2419.0) In-Reply-To: <001a01be85a5$7308b0c0$dd066d8c@sinica.edu.tw> X-Mimeole: Produced By Microsoft MimeOLE V5.00.2014.211 Importance: Normal Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > In particular, I think we are missing a key distinction that the MIME > content-type is not so much the "type" of a resource, but the > type of a particular *publication* of a resource. This is a very good distinction, and a very succint summary. Well done. > Relative to the issue of bundling resources with a document, > I recently put up a proposal for Document Resource Links, for XML. See > http://www.ascc.net/~ricko/drlove.htm > > Rather than extending the MIME headers with lots of > parameter, perhaps just the URI of a single resource like that would allow greater > extensibility. Yes, I think this is absolutely the right way to go. The only thing I would add is that packaging itself has many facets: the "catalog" (drlove, XPDL, etc.) definition, packaging in MIME multipart/*, resource name aliasing, push vs. pull, mixed mode push/pull, etc. that all need to be considered. When we considered this before (for MIME SGML), we concluded that MIME *already* provides sufficient infrastructure... you only really needed to register a few more MIME types for the primary objects (document instances, DTD's, SGML declarations< etc.) and that the rest of the requirements really fall onto the "catalog", or perhaps as you might call it, the "publication specification". > And the URI acts as a "publication type name". This is a nice feature. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA08251 for ietf-xml-mime-bks; Tue, 13 Apr 1999 05:10:51 -0700 (PDT) Received: from gate.sinica.edu.tw (gate.sinica.edu.tw [140.109.4.130]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA08247 for ; Tue, 13 Apr 1999 05:10:50 -0700 (PDT) Received: from pnc01.sinica.edu.tw ([140.109.6.221]) by gate.sinica.edu.tw (8.9.3/8.9.3) with SMTP id UAA27670 for ; Tue, 13 Apr 1999 20:11:02 +0800 (CST) Message-ID: <001a01be85a5$7308b0c0$dd066d8c@sinica.edu.tw> From: "Rick Jelliffe" To: References: <199904130925.SAA23471@sh.w3.mag.keio.ac.jp> Subject: Positions on "List of issues" Date: Tue, 13 Apr 1999 20:02:05 +0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: My 2 cents worth: > Issue 1: Proposals for additional parameters in the past I agree with Tim Bray that it is inappropriate to give the DTD in a parameter: in particular, because XML content models are basically glorified assert() statements. DOCTYPE declarations are fine and appropriate where they are. But I think we need to have some clearer idea of what the MIME headers are supposed to do; is there a nice functional demarcation between the headers and the resource? In particular, I think we are missing a key distinction that the MIME content-type is not so much the "type" of a resource, but the type of a particular *publication* of a resource. For example, lets take a VML file: if I want to publish it for viewing on a VML browser, I should be able to send it out with the MIME type image/vml (or whatever). If I want to publish it out for viewing by generic XML tools, I send it as text/xml. If I want to publish it for viewing as text, I send it as text/plain. (Browsers are, of course, free to implement any application dispatching system they like, which could circumvent my intentions, but that is life.) So IMHO the MIME content-types should be geared at helping information providers publish documents in forms they think are useful. In other words, it is not the function of the MIME header to describe the resource in general; the MIME header should describe the document enough for the particular uses that the information provider has in mind. With this distinction in mind, we can judge the various parameters suggested using the simple maxim that "when I publish a resource, I publish it with a specific use in mind (even if you use it differently)", which means that we dont need to be overly concerned with "graceful degradatation" or to provide an elaborate class mechanism (not to deny that the class relations exist). Furthermore, let me bring up another problem with parameters: the parameters have to be sourced from somewhere: everytime we have to duplicate information from inside an XML document into a header, we create the chance for a mismatch. If we need fast indexing to elements inside a document, we should invent an index format: eg html 23 head 32 meta 44 meta 55 meta 68 to allow (normalized) character indexing into an XML instance. That would be far more useful in many circumstances than cluttering up the header with lots of parameters. > Issue 2: Type of XML mime entities It would be useful to have a text/dtd (and therefore application/xml) MIME type. text/xml should be used for XML entities (well-formed or not). > Issue 3: UTF-16 > RFC 2376 should be revised when charsets for UTF-16 are registered. Yes. And XML appendix F should be revised simultaneously, so that the specifications are kept in sync. > Issue 4: Characters .vs. bytes > An XML MIME entity is a sequence of characters as opposed to a > sequence of bytes. RFC 2376 is not really clear about this. This is the old question. When we discussed it before, didn't we say that: * a text/xml entity is a sequence of characters * an application/xml entity is a sequence of bytes? I hope an application/* is not a sequence of characters. > Issue 5: Packaging > There should be a mechanism for packaging an XML document together > with its stylesheet, catalog, and referenced resources (e.g., links, > external entities). Relative to the issue of bundling resources with a document, I recently put up a proposal for Document Resource Links, for XML. See http://www.ascc.net/~ricko/drlove.htm Rather than extending the MIME headers with lots of parameter, perhaps just the URI of a single resource like that would allow greater extensibility. And the URI acts as a "publication type name". > Issue 6: Ambiguity of CCS conversion > If this is the case, it might make sense to introduce a parameter > "map" to precisely specify which mapping should be used. This also could have bearing on the PUA (private use area) character problem, and the problem of corporate character sets (e.g. Hong Kong's GCCS). > Issue 7: The default of the charset parameter Chris Lilley's recent proposal to revised RFC2376 is as below: > 1) Require explicit charset for overriding the internal encoding > declaration, so if one really wants to re-label a document as US-ASCII > one actually has to send it out as text/xml; charset="US-ASCII" > 2) Define the absence of an explicit charset encoding in the MIME > header not as "US-ASCII" but as "use encoding in XML instance" in > accordance with the XML 1.0 Recommendation. Yes. But...We should encourage the use of application/xml when data integrity is at a premium, and text/xml when data accessibility is a premium. I wonder whether the following is actually what is required to make text/xml work: * if the MIME charset and the XML encoding PI concur, the entity is accepted with the MIME charset; * if the MIME charset and the XML encoding PI disagree, *and* the content-type is application/xml, the resource should be accepted using the XML encoding PI; * if the MIME charset and the XML encoding PI disagree, *and* the content-type is text/xml, the user-agent may (at user selection): - accept the document using the MIME charset (default; status quo in RFC; indicative of transcoding) - accept the document using the XML PI (indicative of poor server labelling); - follow some policy and heuristics determined by the user-agent (indicative that data integrity is not the highest priority); - reject the entity and request it again as application/xml (safest); where "concurring" takes into account the different defaults. This is all so complicated, maybe we should just always recommend application/xml! Rick Jelliffe Academia Sinica Computing Center Taipei, Taiwan Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id DAA06178 for ietf-xml-mime-bks; Tue, 13 Apr 1999 03:34:04 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id DAA06174 for ; Tue, 13 Apr 1999 03:34:02 -0700 (PDT) Received: by mx.fujixerox.co.jp; id TAA04750; Tue, 13 Apr 1999 19:34:19 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma004625; Tue, 13 Apr 99 19:34:05 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id TAA18199 for ; Tue, 13 Apr 1999 19:32:01 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id TAA18368 for ; Tue, 13 Apr 1999 19:34:04 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id TAA01502 for ; Tue, 13 Apr 1999 19:32:05 +0900 Message-Id: <199904131033.AA00281@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Tue, 13 Apr 1999 19:33:59 +0900 To: ietf-xml-mime@imc.org Subject: Re: DTD media type? In-Reply-To: <199904130925.SAA23471@sh.w3.mag.keio.ac.jp> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Martin J. Duerst wrote: > > Makoto, I think the things you have mentioned in your mail are quite important. > But my guess is that many of the participants in this discussion don't have > the necessary background. Is there somewhere a web page where all these terms > are defined and explained with simple examples, or something similar? I am obsessed by XML... Here is an imprecise-but-not-totally-inappropriate analogy. XML documents are source programs. External DTD subsets are header files that contain declarations and are referenced at the beginning of XML documents (note: at most one external DTD subset is referenced by one XML document). External parsed entities are include files that contain source program fragments and are referenced in the middle of XML documents. External parameter entities are include files that contain declarations and are referenced by external DTD subsets. XML document ----------------> external DTD subset | |--> external parameter entity | |--> external parsed entity The BNF for XML documents and that for external DTD subsets are quite different. On the other hand, some external parsed entities are legal XML documents, and some external parameter entities are legal external DTD subsets. Viewers for XML documents and viewers for external DTD subsets are quite different. (Please forgive my white lie. I think that this is enough for our discussion. > XML experts) If you would like to know the truth, the best document on the WWW is Tim's annotated XML. Its URL is: http://www.xml.com/axml/testaxml.htm DTDs, external DTD subsets, and internal DTD subsets are defined in 2.8 of XML 1.0 (http://www.xml.com/axml/target.html#dt-doctype) [Definition:] The XML document type declaration contains or points to markup declarations that provide a grammar for a class of documents. This grammar is known as a document type definition, or DTD. The document type declaration can point to an external subset (a special kind of external entity) containing markup declarations, or can contain the markup declarations directly in an internal subset, or can do both. The DTD for a document consists of both subsets taken together. Entitites are defined in Section 4 of XML 1.0. (http://www.xml.com/axml/target.html#sec-physical-struct) Parameter entity [Definition:] Parameter entities are parsed entities for use within the DTD. These two types of entities use different forms of reference and are recognized in different contexts. Furthermore, they occupy different namespaces; a parameter entity and a general entity with the same name are two distinct entities. Parsed entity Entities may be either parsed or unparsed. [Definition:] A parsed entity's contents are referred to as its replacement text; this text is considered an integral part of the document. Hope this helps. Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id CAA01607 for ietf-xml-mime-bks; Tue, 13 Apr 1999 02:25:37 -0700 (PDT) Received: from sh.w3.mag.keio.ac.jp (sh.w3.mag.keio.ac.jp [133.27.194.41]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id CAA01601 for ; Tue, 13 Apr 1999 02:25:34 -0700 (PDT) Received: from enoshima (pv24.mag.keio.ac.jp [133.27.195.124]) by sh.w3.mag.keio.ac.jp (8.9.0/3.6W-W3C/Keio) with SMTP id SAA23471; Tue, 13 Apr 1999 18:25:39 +0900 (JST) Message-Id: <199904130925.SAA23471@sh.w3.mag.keio.ac.jp> X-Sender: duerst@sh.w3.mag.keio.ac.jp X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3-J (32) Date: Tue, 13 Apr 1999 18:05:43 +0900 To: MURATA Makoto From: "Martin J. Duerst" Subject: Re: DTD media type? Cc: ietf-xml-mime@imc.org In-Reply-To: <199904110758.AA00259@archlute.apsdc.ksp.fujixerox.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 16:58 99/04/11 +0900, MURATA Makoto wrote: > In the xml-dev mailing list, some people requested a media type for DTD (to > be precise, an external DTD subset), since browsers should be able to launch > a DTD viewer for DTDs. One could also argue that an additional parameter of > text/xml and application/xml is enough for that purpose. [rest deleted] Makoto, I think the things you have mentioned in your mail are quite important. But my guess is that many of the participants in this discussion don't have the necessary background. Is there somewhere a web page where all these terms are defined and explained with simple examples, or something similar? Regards, Martin. #-#-# Martin J. Du"rst, World Wide Web Consortium #-#-# mailto:duerst@w3.org http://www.w3.org Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id VAA12189 for ietf-xml-mime-bks; Mon, 12 Apr 1999 21:07:33 -0700 (PDT) Received: from tribble.eps.inso.com (tribble.eps.inso.com [198.112.118.8]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id VAA12185 for ; Mon, 12 Apr 1999 21:07:28 -0700 (PDT) Received: from endymion (modem_f [199.93.212.248]) by tribble.eps.inso.com (8.9.1/8.9.1) with SMTP id AAA24656 for ; Tue, 13 Apr 1999 00:03:56 -0400 (EDT) Reply-To: From: "Gavin Thomas Nicol" To: Subject: RE: Starting the ietf-xml-mime mailing list Date: Mon, 12 Apr 1999 23:25:22 -0400 Message-ID: <003601be8563$9dae87b0$0100007f@eps.inso.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2212 (4.71.2419.0) In-Reply-To: <3.0.32.19990407094512.00cee720@pop.intergate.bc.ca> X-Mimeole: Produced By Microsoft MimeOLE V5.00.2014.211 Importance: Normal Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > 1. something generic gets the XML and parses it > 1.a the generic something displays the XML to a human using a > stylesheet, possibly with help from other logic for > embedded chunks > from different namespaces. > 1.b the generic something invokes some application. > > The 1.a example is of course Web browsers (although it seems there > are some nasty architectural holes in how you dispatch control for > embedded chunks of XML). I have a hard time thinking of a 1.b > example. > > 2. An app gets invoked to deal with a resource that happens to > be encoded in XML, and the app uses its built-in XML parser. > This case probably wants its own media type; the fact that > the encoding is XML is hardly material. I would say that 1b is roughly equivalent to 2, except for an additional level of abstraction. I actually prototyped, a while ago now, 1b using the standard set of mail tools on Unix. I basically specified a compound document/application object in a TR9401 catalog (a poxy medium it turns out, that needed a lot of fixing, and a number of extensions). That catalog could be transmitted to a generical application that then invoked whatever else was appropriate (in this case, DynaText, Panorama, and Web browsers). I think we need to clearly seperate the issue of packaging a single XML instance/entity, and a compound document. I would argue that the former is almost entirely devoid of any application semantics (being either simple text/xml or application/xml), but the latter *intrinsically* has *some* semantics associated with it. I guess this is basically supporting the notion that application specific uses of XML should have application defined media types, but there is a slight difference in the *mechanism* that I am talking about. We could have something like xml/processing-specification or something suchlike, with an associated handler, and that handler could be reponsible for the dispatch (not part of the MIME world at all). Again, I prototyped something like this some time ago, and it did work well, even on top of *existing* (this was '95) MIME infrastructure. I should note that both Simon St. Laurent and Chris Lilley have been making noise about such "catalogs" recently as well. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id TAA03417 for ietf-xml-mime-bks; Sun, 11 Apr 1999 19:49:19 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id TAA03408 for ; Sun, 11 Apr 1999 19:49:17 -0700 (PDT) Received: by mx.fujixerox.co.jp; id LAA00863; Mon, 12 Apr 1999 11:49:28 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma000716; Mon, 12 Apr 99 11:48:52 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id LAA09441 for ; Mon, 12 Apr 1999 11:46:47 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id LAA21003 for ; Mon, 12 Apr 1999 11:48:50 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id LAA05594 for ; Mon, 12 Apr 1999 11:46:51 +0900 Message-Id: <199904120248.AA00265@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Mon, 12 Apr 1999 11:48:44 +0900 To: ietf-xml-mime@imc.org Subject: What we have agreed on MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Having read the disussion so far, I believe that we have agreed on a few things and would like to know if somebody disgarees. 1. Registration of media subtypes is easy. 2. Dispatch based on parameters are not widely supported. 3. Fallback to general-purpose XML applications is not useful. 4. Document-like XML documents can be handled by general-purpose XML viewers If these are agreed on, we can eliminate some options and concentrate on the rest. If you disagree with these four points, please speak up now. Cheers, Makoto ---------------------------------------------------------- 1. Registration of media subtypes is easy. "Registrations now routinely take only a few days if they don't contain egregious errors." (Ned) "Registrations containing errors take longer, of course. But feedback is quick, typically taking only a day or two, so the burden is on the person doing the registration to turn the thing around in a timely way." (Ned) "The registration process is the same (i.e. fast) in *any* tree that currently exists. The slowness associated with the IETF tree has to do with RFC review, which is an entirely separate process from type registration." (Ned) "The standards say that RFC documentation is only required for registration in the IETF tree, and in practice none of the many registered XML-based types have been backed up with RFCs." (Ned) "Moreover, relatively few types belong in the IETF tree." (Ned) 2. Dispatch based on parameters are not widely supported. "The lack of ability to dispatch on parameters in most applications that support MIME. Not only do applications lack this ability, there are also quite a few contexts where MIME labelling is used that don't support parameters, period." (Ned) "Many current implementations of content dispatch don't allow dispatch based on media type parameters, in any case." (Larry) 3. Fallback to general-purpose XML applications is not useful. "What's the XML parser going to do with this block of data? Display it? Not terribly valuable. Get some namespace information from the inside and then dispatch based on the namespace? Possibly valuable, but this begs the question of why wasn't that information out in the MIME headers." (Paul) "what experience has shown is that fallback strategies of *any* sort tend to be overrated. In almost every case something has messed it up. Either we got the granularity wrong (and I see a very good chance of this happening here given the emergence of alternative forms of XML), or it didn't prove to offer useful functionality, or it simply didn't deploy in the manner in which we envisioned. About the only success story we have, actually, are the image/audio/video top-level types, and while these have worked out tolerably well, their actual value to end users isn't that great." (Ned) "Not even possible, in some cases. XML is being used for all sorts of things from serialising Java Beans to Web server configuration files to interprocess communication - a lot of these uses are not especially "displayable". In some cases, the fact that they are written in XML is the least important thing about them. These are likely to need specialised registrations, too. Further, if the specification for any such case is not controlled by a single vendor, then registration in the vendor tree does not seem appropriate. This would be the case for situations ranging from a small vendor group (such as the Flashpix group) through groups such as W3C to bodies such as ISO, ITU, IEE and so on." (Chris) 4. Document-like XML documents can be handled by general-purpose XML viewers "1.a the generic something displays the XML to a human using a stylesheet, possibly with help from other logic for embedded chunks from different namespaces." (Tim) "Then there is a second class of uses which are essentially textual, where the XML markup is being used to structure headings, footnotes, chapters and suchlike document-like things. These things do indeed benefit, if not recognised, from being "displayed" and may even contain an internal link to a stylesheet which can be used to display them. I think that dispatching this 'marked up text' class of uses to a single parser/viewer, such as a browser, make sense (not in all cases of course, and editing should be distinguished from viewing, but full mailcap files can do that) and thus, a MIME labelling of text/xml would make sense." (Chris) Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id NAA23392 for ietf-xml-mime-bks; Sun, 11 Apr 1999 13:27:03 -0700 (PDT) Received: from marine.sonic.net (marine.sonic.net [208.201.224.37]) by mail.proper.com (8.8.8/8.8.5) with SMTP id NAA23388 for ; Sun, 11 Apr 1999 13:27:02 -0700 (PDT) Received: (qmail 31480 invoked from network); 11 Apr 1999 20:27:13 -0000 Received: from sub.sonic.net (208.201.224.8) by marine.sonic.net with SMTP; 11 Apr 1999 20:27:13 -0000 Received: from bolt.sonic.net (tallen@bolt.sonic.net [208.201.224.36]) by sub.sonic.net (8.8.8/8.8.5) with ESMTP id NAA28565; Sun, 11 Apr 1999 13:27:12 -0700 X-envelope-info: Received: (from tallen@localhost) by bolt.sonic.net (8.8.8/8.7.3) id NAA28609; Sun, 11 Apr 1999 13:27:12 -0700 Date: Sun, 11 Apr 1999 13:27:12 -0700 From: Terry Allen Message-Id: <199904112027.NAA28609@bolt.sonic.net> To: ietf-xml-mime@imc.org, masinter@parc.xerox.com, tallen@sonic.net Subject: RE: Mixed-format and Unpacking Expectations Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry wrote: | When I asked | | In the case where you're allowed to have a document that mixes | | traditional HTML, MathML, Vector Graphics ML, etc., are these | | separate "applications" or are they one "application" ("renderable | | XML document")? | | I was thinking of an XML application which allowed, in a single | body part, all of those namespaces. In the case where you have | separate body parts, MHTML is probably the best you can do. Ah. My answer would be that the use of "XML namespaces" does not imply separate applications (although you could figure out how to specify that an "XML namespace" should be mapped to an application, as NOTATION was used to do). | > In both cases I used the basis of the MHTML work, but tried to avoid | > putting information about relations of parts in the MIME headers, so | > that you could discard the MIME packaging without loss of information. | | MHTML doesn't put "information about the relations of parts" in the | MIME headers. It just puts the identity of each part in the wrapper. | If you have body parts that are self-identifying (they contain their | own uri/cid or whatever) then you can reassemble. Yes, I was thinking of RFC 2387 (Multipart/related), which uses Content-Disposition, possibly encoding structural information not borne elsewhere. I see now that RFC 2557 (MHTML) doesn't (and the bibliographic reference to RFC 2183 (Content-Disposition), CONDISP, is apparently dangling). But then, I was ignoring relative URLs. regards, Terry Terry Allen Commerce One, Inc. Business Language Designer 1600 Riviera Ave., Suite 200 Advanced Technology Group Walnut Creek, Calif., 94596 tallen[at]sonic.net Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id LAA22891 for ietf-xml-mime-bks; Sun, 11 Apr 1999 11:35:46 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id LAA22887 for ; Sun, 11 Apr 1999 11:35:45 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <52347(2)>; Sun, 11 Apr 1999 11:35:48 PDT Received: from copper.parc.xerox.com ([13.2.17.216]) by thelma.parc.xerox.com with SMTP id <97663>; Sun, 11 Apr 1999 11:35:36 PDT From: "Larry Masinter" To: "Terry Allen" , Subject: RE: Mixed-format and Unpacking Expectations Date: Sun, 11 Apr 1999 11:35:31 PDT Message-ID: <000e01be844a$1403eb00$d811020d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-Reply-To: <199904102050.NAA15702@bolt.sonic.net> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: When I asked | In the case where you're allowed to have a document that mixes | traditional HTML, MathML, Vector Graphics ML, etc., are these | separate "applications" or are they one "application" ("renderable | XML document")? I was thinking of an XML application which allowed, in a single body part, all of those namespaces. In the case where you have separate body parts, MHTML is probably the best you can do. > In both cases I used the basis of the MHTML work, but tried to avoid > putting information about relations of parts in the MIME headers, so > that you could discard the MIME packaging without loss of information. MHTML doesn't put "information about the relations of parts" in the MIME headers. It just puts the identity of each part in the wrapper. If you have body parts that are self-identifying (they contain their own uri/cid or whatever) then you can reassemble. Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id AAA17633 for ietf-xml-mime-bks; Sun, 11 Apr 1999 00:58:45 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id AAA17629 for ; Sun, 11 Apr 1999 00:58:43 -0700 (PDT) Received: by mx.fujixerox.co.jp; id QAA14834; Sun, 11 Apr 1999 16:58:51 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma014830; Sun, 11 Apr 99 16:58:33 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id QAA17298 for ; Sun, 11 Apr 1999 16:56:27 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id QAA05223 for ; Sun, 11 Apr 1999 16:58:31 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id QAA21660 for ; Sun, 11 Apr 1999 16:56:33 +0900 Message-Id: <199904110758.AA00259@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Sun, 11 Apr 1999 16:58:24 +0900 To: ietf-xml-mime@imc.org Subject: DTD media type? MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: In the xml-dev mailing list, some people requested a media type for DTD (to be precise, an external DTD subset), since browsers should be able to launch a DTD viewer for DTDs. One could also argue that an additional parameter of text/xml and application/xml is enough for that purpose. Other than external DTD subsets and XML documents, there are two types of XML network entities. They are external parsed entities and external parameter entities. At present, RFC 2376 says that text/xml and application/xml can be used for all of the four types. No mechanisms for distinguishing the four types are present. Can we use XML processors to distinguish these four types? The answer is No. A DTD does not parse as an XML document. An external parsed entity does not typically parse as an XML document. (Note: it is possible to create an external parsed entity which also parses as an XML document.) An external parameter entity does not parse as an XML document. (Note: an external parameter entity can also become an external DTD subset.) Then, can we develop some other program to distinguish the four types? It is possible, but not likely. To do such autodetection, programs have to understand the charset parameter, handle the specified charset, and then compare the text against the BNFs for the four types. People will not implement such complicated autodetection, in my humble opinion. Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id NAA13799 for ietf-xml-mime-bks; Sat, 10 Apr 1999 13:50:10 -0700 (PDT) Received: from marine.sonic.net (marine.sonic.net [208.201.224.37]) by mail.proper.com (8.8.8/8.8.5) with SMTP id NAA13795 for ; Sat, 10 Apr 1999 13:50:08 -0700 (PDT) Received: (qmail 21038 invoked from network); 10 Apr 1999 20:50:14 -0000 Received: from sub.sonic.net (208.201.224.8) by marine.sonic.net with SMTP; 10 Apr 1999 20:50:14 -0000 Received: from bolt.sonic.net (tallen@bolt.sonic.net [208.201.224.36]) by sub.sonic.net (8.8.8/8.8.5) with ESMTP id NAA05543 for ; Sat, 10 Apr 1999 13:50:14 -0700 X-envelope-info: Received: (from tallen@localhost) by bolt.sonic.net (8.8.8/8.7.3) id NAA15702 for ietf-xml-mime@imc.org; Sat, 10 Apr 1999 13:50:14 -0700 Date: Sat, 10 Apr 1999 13:50:14 -0700 From: Terry Allen Message-Id: <199904102050.NAA15702@bolt.sonic.net> To: ietf-xml-mime@imc.org Subject: Mixed-format and Unpacking Expectations Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I'd like to add remarks on topics I haven't seen dealt with at any length yet: mixed format compound documents and expectations for MIME unpacking. Here are some quotes of what has been said: | MURATA Makoto, Paul Hoffman, Frank Dawson, Jim Whitehead | 1. Problem statement | | We would like the MIME parser to be able to dispatch different sorts | of XML documents to different applications, such as specialized | programs that handle just one type of XML document. Because MIME | parsers do not look inside the MIME parts, identifiying the sort of | documents must be done in the MIME headers. However, neither text/xml | nor application/xml allow such information. | ... | (3) A new parameter "externalid" for text/xml and application/xml | | This parameter specifies the externalID from the DOCTYPE of the XML | document (if the DOCTYPE is present). Examples would be: | ... | Note: None of the above proposals handle non-monolithic XML documents | very well, | since different islands of non-monolithic XML documents belong to different | namespaces and thus different schemata. | =================== | Later, Murata Makoto wrote: | Issue 5: Packaging | | There should be a mechanism for packaging an XML document together | with its stylesheet, catalog, and referenced resources (e.g., links, | external entities). One possibility is MHTML. | =================== | Larry asked: | In the case where you're allowed to have a document that mixes | traditional HTML, MathML, Vector Graphics ML, etc., are these | separate "applications" or are they one "application" ("renderable | XML document")? | ==================== Mixed-format compound documents. I have imagined complex documents that are not pure XML. Such a document would have a root entity (cover page, table of contents) that gives access to others (which is why it's a document rather merely a web). That root entity could be PDF, XML, Word, plain text, CGM, you name it. Other entities could be XML, Word, PDF, etc. and on and on. I want to be able to package up such a document in MIME, and I think of "nonmonolithic" XML documents as a special case of this format-generic complex document. I'd like to solve the general problem AND solve the XML problem together. I've made several proposals for doing so: "Package or Perish", an SGML '97 paper, and "MIME Multipart/Related for CBL", possibly accessible s.v. "Related Documents" at http://www.veosystems.com/xml/cbl/cbl-1.1/doc/index.html In both cases I used the basis of the MHTML work, but tried to avoid putting information about relations of parts in the MIME headers, so that you could discard the MIME packaging without loss of information. I don't have any attachment to the details of either of those proposals: the week before the SGML '97 conference my colleagues and I worked up half a dozen combinations of MIME semantics to do the job, and any proposal that works is fine by me. I invented a text/x-compounddoc subtype for mixed-format compound documents, perhaps pointlessly: is it the opinion of this group that the root entity's MIME type is what should be used to label the whole (which is related to what Larry was asking)? or maybe the MIME type of the manifest (see next)? Expectations for MIME unpacking. There may be XML documents composed of very many pieces: My-enormous-catalogue-container Catalogue-entry-1 Catalogue-entry-2 Catalogue-entry-3 ... Catalogue-entry-100,000 Each of these catalogue entries may have an identifier, which could be listed in a manifest (in XML, say) that is the first body part of a multipart MIME message. The recipient may know he is interested only in Catalogue-entry-98,256. It seems to me that it might be more efficient to obtain that part by extracting and parsing the manifest and then searching for the MIME header of the wanted body part (thus making recursive use of the MIME packaging) rather than having the MIME unpacker unpack all of the MIME message first. I'm no MIME expert, so I don't know if that's reasonable, but I am uneasy about assuming that unpacking should be done before any subsequent processing. (Perhaps no such assumption has been made ...) regards, Terry Terry Allen Commerce One, Inc. Business Language Designer 1600 Riviera Ave., Suite 200 Advanced Technology Group Walnut Creek, Calif., 94596 tallen[at]sonic.net Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id UAA00143 for ietf-xml-mime-bks; Thu, 8 Apr 1999 20:35:10 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id UAA00138 for ; Thu, 8 Apr 1999 20:35:05 -0700 (PDT) Received: by mx.fujixerox.co.jp; id MAA08018; Fri, 9 Apr 1999 12:35:00 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma007992; Fri, 9 Apr 99 12:34:47 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99040814) with ESMTP id MAA04138 for ; Fri, 9 Apr 1999 12:32:41 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id MAA23912 for ; Fri, 9 Apr 1999 12:34:46 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id MAA13097 for ; Fri, 9 Apr 1999 12:32:47 +0900 Message-Id: <199904090334.AA00252@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Fri, 09 Apr 1999 12:34:37 +0900 To: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <370A8FB6.64B32EEB@w3.org> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Chris Lilley wrote: > It struck me as an entirely reasonable question, in particular since the > RFC that defines text/xml and application/xml refers to "MIME-like > protocols" which seems to imply that HTTP is not MIME (something I have > heard asserted in the past). RFC 2068(Hypertext Transfer Protocol -- HTTP/1.1) says: ---------------------------------------------------- 19.4 Differences Between HTTP Entities and MIME Entities HTTP/1.1 uses many of the constructs defined for Internet Mail (RFC 822) and the Multipurpose Internet Mail Extensions (MIME ) to allow entities to be transmitted in an open variety of representations and with extensible mechanisms. However, MIME [7] discusses mail, and HTTP has a few features that are different from those described in MIME. These differences were carefully chosen to optimize performance over binary connections, to allow greater freedom in the use of new media types, to make date comparisons easier, and to acknowledge the practice of some early HTTP servers and clients. Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id KAA17653 for ietf-xml-mime-bks; Thu, 8 Apr 1999 10:21:55 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id KAA17649 for ; Thu, 8 Apr 1999 10:21:54 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id NAA03579; Thu, 8 Apr 1999 13:22:37 -0400 Message-ID: <370CAACA.282F3F93@w3.org> Date: Thu, 08 Apr 1999 15:10:34 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Frank Dawson CC: Larry Masinter , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <04a501be814c$7203c5a0$f95472c6@fdawson.lotus.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Frank Dawson wrote: > Actually, the current MIME content type definition for "text/calendar" > provides for MIME header parameter that CUAs are using to scan the inbox for > the "new invitations". Okay, > This is what gave me concern when I read the content > type definition for text/xml and application/xml. It doesn't allow an > application to detect what kind of XML object is in the email. If you are pointing out the utility of parameters for finer granularity of labelling in general, then I agrree it can help. > For our > application area, it is disfunctional. It is imparing the use of XML for > representing iCalendar objects (and certainly other application objects > too). I sense from this a worry that existing registered uses of XML would need to re-register to use text/xml. If that is your worry, then I would say that I do not believe that this is the intention. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id KAA17643 for ietf-xml-mime-bks; Thu, 8 Apr 1999 10:21:49 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id KAA17639 for ; Thu, 8 Apr 1999 10:21:48 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id NAA03571; Thu, 8 Apr 1999 13:22:29 -0400 Message-ID: <370CAAC5.B38E4A1@w3.org> Date: Thu, 08 Apr 1999 15:10:29 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Frank Dawson CC: Larry Masinter , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <04a601be814c$73738240$f95472c6@fdawson.lotus.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Frank Dawson wrote: > > Larry Masinter wrote, in part: > > >I'm saying you definitely have a problem: you have a complex space > >of possible objects: > > NO, this is not a complex problem. This is an existing 20+ year old mail > enabled application. This nut has already been cracked for Internet > developers using the "text/calendar" content definition. I queried > Kurita-san and Paul Hoffman because I was interested in utilizing XML > representation of iCalendar. We have a DTD defined. It is an isomer of the > iCalendar standard format, So, the mechanics and all the semantics of text/calendar are retained but it merely uses a different syntax? In that case, it would seem that something like text/xcalendar would meet your needs, and that apart from the syntactic portion, the defining specification would see "see text/calendar" in a great many places (or have the same text copied, whatever). > There needs to be > some balance between an infinite number of media types/subtypes for each > transaction type and a smaller, managable number of media types for each > logical application object type. Yes. This is the hierarchical model, as opposed to the flat model. Parameters provide a third level of hierarchy below the content type and content subtype levels. > As Ned has pointed out, this example and > other show that leaving "hooks" on the outside of the object wrapper is very > useful in providing a scalable, practical Internet solution using XML. The hooks are particularly useful for specialised types such as calendaring. For a more generic "this is a textual document marked up in XML" type, the difficulty is finding hooks of suitable generality. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id GAA15052 for ietf-xml-mime-bks; Thu, 8 Apr 1999 06:16:19 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id GAA15048 for ; Thu, 8 Apr 1999 06:16:18 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <52287(3)>; Thu, 8 Apr 1999 06:17:03 PDT Received: from copper.parc.xerox.com ([13.0.211.121]) by thelma.parc.xerox.com with SMTP id <99260>; Thu, 8 Apr 1999 06:17:00 PDT From: "Larry Masinter" To: Subject: RE: Starting the ietf-xml-mime mailing list Date: Thu, 8 Apr 1999 06:16:45 PDT Message-ID: <000201be81c2$0cedc460$d111020d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 Importance: Normal In-Reply-To: <370CA5FC.46F75563@w3.org> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I'm not sure about this group. Here we have a bunch of people arguing about labelling things on the outside and not requiring processors to go inside the body to determine the actual content, yet everyone seems to be content with having the entire discussion with a "Subject" line of "RE: Starting the ietf-xml-mime mailing list". Regards, Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA14767 for ietf-xml-mime-bks; Thu, 8 Apr 1999 05:51:42 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA14763 for ; Thu, 8 Apr 1999 05:51:41 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA17870; Thu, 8 Apr 1999 08:52:23 -0400 Message-ID: <370CA5FC.46F75563@w3.org> Date: Thu, 08 Apr 1999 14:50:04 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Larry Masinter CC: Earthlink , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <002401be8141$6fe9c040$aa66010d@copper.parc.xerox.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: > [Frank wrote] > > In addition, though, we also want to get at subtypes of objects. Or in the > > case of MIME type/subtypes, this would be the "sub-sub type". For example, > > for a calendar object (text/calendar) we want to pull to the client just the > > "event invitations". This would be the "sub sub type" of type=text, > > subtype=calendar. > > This is a good example of a problem that specialized media types won't solve. But it sure cuts down the class of data to be further processed. Instead of searching through the entire mailbox/the entire server, just search in the text/calendar resources. > You might also want to scan your email for "event invitations from my boss", > and you can't solve that problem with specialized MIME media types. You can't solve that problem in its entirety with specialised MIME media types, but you can go a good part of the way and have a better start than, for example, sending all calendar events as text/plain. text/calendar;category=work;recurring=monthly (to take a suggestive but doubtles invalid example) would help even more - the parameters could be used to cut down on the search spoace even further. > So the > question is: are there any realistic cases where having a "text/calendar" > distinction in the email header actually helps substantially in deciding > which email bodies to retrieve? Yes; especially in the case of IMAP where the initial selection of bodis is done on the server and likely ones are sent to the client for the calendar program to further process. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA14716 for ietf-xml-mime-bks; Thu, 8 Apr 1999 05:45:14 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA14712 for ; Thu, 8 Apr 1999 05:45:13 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA17493; Thu, 8 Apr 1999 08:45:54 -0400 Message-ID: <370CA477.C6DFAD6E@w3.org> Date: Thu, 08 Apr 1999 14:43:35 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Earthlink CC: Larry Masinter , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <033901be813f$a7ace040$f95472c6@fdawson.lotus.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Earthlink wrote: > > >It's not clear that specialized media types solve any problem at all, > >in the case of XML that already contains a document declaration. > > The overhead of having to open up every XML document to find out what > document type it is is not practical. As in the case of email, all I should > have to do is ask for a particular type of object from the store and get it. Yes. Thanks for bringing to our attention the fact that IMAP uses servers, as well as HTTP; since I use POP I tend to forget about what IMAP does. Is it possible to request the "best" of several multipart/alternate message bodyparts over IMAP, where "best" means the preferences of MIME type that the user has? > In addition, though, we also want to get at subtypes of objects. Or in the > case of MIME type/subtypes, this would be the "sub-sub type". For example, > for a calendar object (text/calendar) we want to pull to the client just the > "event invitations". This would be the "sub sub type" of type=text, > subtype=calendar. What about parameters, can these be handled? For example the CGM registration (image/cgm) defined two mandatory parameters; this was a problem at the time because parameters were not well handled by current implementations. But recently, W3C made WebCGM (a particuklar profile) a Recommendation, and were able to use those parameters to indicate thata particular CGM used the WebCGM profile. This was handy, no additional registration was necessary and the general semantics of imege/cgm still apply to WebCGM, but specific semantics are also added. Would IMAP be able to fetch image/cgm;Version=4;ProfileId=WebCGM bodyparts specifically? This use of parameters for profiles of a registered type/subtype combination sounds to me much like the possibilities with registering text/xhtml and then declaring the various HTML profiles for mobile, TV etc. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA14614 for ietf-xml-mime-bks; Thu, 8 Apr 1999 05:36:28 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA14610 for ; Thu, 8 Apr 1999 05:36:27 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA17023; Thu, 8 Apr 1999 08:37:00 -0400 Message-ID: <370CA261.E15E3A09@w3.org> Date: Thu, 08 Apr 1999 14:34:41 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Murray Altheim CC: masinter@parc.xerox.com, Ned.Freed@INNOSOFT.COM, murata@apsdc.ksp.fujixerox.co.jp, ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <199904071937.MAA15419@mehitabel.eng.sun.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Murray Altheim wrote: > I don't believe that > resorting to file extensions can possibly be the way of the future. I agree that it should not be the way of the future, but there is some evidence that implementors are moving in this direction. Try serving up a PNG file labelled as image/png but with a .gif extension to a popular browser and see what happens ;-( Similarly, try serving up an XML file with a .txt extension as text/plain and some browsers will still complain "unable to display XML file with stylesheet" and faiul to display it as text - they are sniffing in the content. This is, apparently, because of the amount of unlabelled or mislabelled content which already exists. > We all need a better alternative. Yes. We also need one fairly quickly (all done and dusted in, lets say, three months tops) otherwise whatever solution is proposed will merely be a good idea, but too late. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA14530 for ietf-xml-mime-bks; Thu, 8 Apr 1999 05:29:41 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA14525; Thu, 8 Apr 1999 05:29:40 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA16623; Thu, 8 Apr 1999 08:30:20 -0400 Message-ID: <370CA0D2.2056CC54@w3.org> Date: Thu, 08 Apr 1999 14:28:02 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Ned Freed CC: Larry Masinter , Paul Hoffman / IMC , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <01J9QYRR52GS8WW98O@INNOSOFT.COM> <01J9R178PHF88WWG0C@INNOSOFT.COM> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Ned Freed wrote: > But this then begs the more general question of whether there is to be an > attempt to "design" the XML usage space, and if there is, whether such an > attempt has any chance of succeeding. > > If the answer to this is "no, we don't want to try and control the development, > direction, and use of XML" This is the position of W3C; certain building blocks are made available (foundational blocks such as XML itself, XLink, XPointer, namespaces, etc; useful common things like styleshets, SVG for images, RDF for metadata which can be used or not as appropriate) but the way in which people combine these building blocks is up to them, and the element names that they use (when not using a building block that defines names for them, like XHTML and SVG do) is entirely their own affair. > The resulting > mixtures and granularity will be whatever developers decide is appropriate. Not just developers; increasingly, vertical markets. An XML namespace for real-estate listings, for example. One for dental records. So forth. > And > in such a world I see little value in having an XML top level type. (Perhaps no > real harm, but little value.) The only value I would see is if the fallbacks and other behaviours of the text/* tree were seen to be unavoidable and made the use of XML too fragile there. XML element names and element content can use all sorts of Unicode characters. Fallbacks to text/plain are not useful in general, and fallbacks to 7-bit US-ASCII risk manglng the data. On the other hand, as you said in another post: > About the only success story we have, > actually, are the image/audio/video top-level types, and while these have > worked out tolerably well, their actual value to end users isn't that great. If it can be assumed that a program which falls back to text/plain has already lost significant semantics anyway, and if it can be assumed that such fallback is rarely of value and rarely happens, then the use of text/xml is useful. If on the other hand the fallback is seen asa n unavoidable problem, then an xml/* tree would, indeed, have value simply by lifting such restrictions. > And in such a world a top-level XML type might > have some value, if only as a place to attach the ruleset. Right, that was what I was trying to say. > (Delegation of XML > registration would also be something to consider.) Perhaps, but who would own it? Oasis, perhaps? My sense is that W3C is not interessted in being a central repository for all possible uses of XML, many of which are not Web related in any way. -- Chris > > I basically don't have an opinion on which way this should go. My one > observation is that the IETF at least has typically opted to try and stay out > of areas like this in the past. > > Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA14398 for ietf-xml-mime-bks; Thu, 8 Apr 1999 05:16:33 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA14392; Thu, 8 Apr 1999 05:16:32 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA15811; Thu, 8 Apr 1999 08:17:11 -0400 Message-ID: <370C9DB9.CDF2DEED@w3.org> Date: Thu, 08 Apr 1999 14:14:49 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Larry Masinter CC: Ned Freed , Paul Hoffman / IMC , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <001301be811e$5a2308c0$aa66010d@copper.parc.xerox.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: > > > > I tend to lean towards "every application gets a new media type". > > > > In case it isn't obvious by now, so do I. > > This is a fine maxim, but it begs the question: what constitutes > a separate, distinct application, vs a modification, profile, > extension, or varation of an old one? Thats a good question, but part of it comes down to monolighic versus granular compound documents. > In the case where you're allowed to have a document that mixes > traditional HTML, (I'm assuming you mean XHTML here, ie HTML written in XML. Sop, all the things you citer are written in XML, and constitute one large XML instance using multiple namespaces). > MathML, Vector Graphics ML, etc., are these > separate "applications" or are they one "application" ("renderable > XML document")? If sens as separate bodyparts, which is possible, then they would all be separate "applications". If sent as one big XML instance, then in this case I would ay it would be text/xml. Once XLink and XPointer get more widely deployed, we are likely (IMHO) to see people moving away from this class of monolithic document and instead using small skeleton documents, written in XML and using XPointer transclusion to reference different media pieces (graphics, math, audio, etc) some (many) orf which are writen in XML , but each with their own label. This granularity allows finer control by mail user agents (they can figure out which bodyparts they understand) and allows the benefits of cacheing over HTTP as different compound documents reuse different component pieces. So (to get back to Larrys point) while we may see monolithic multimnamespace documents which can only really be labelled as text/xml, we will also alongside that see smaller more granular compound documents, where a correspondingly finer grained labelling of each component is more appropriate. Since it doesn't seem to have come up yet, I will also note the concept of content negotiation, as used by HTTP; where MIME labelling is used in negotiations between client and server. I guess this could also apply to email in the case of external bodyparts, but am not sure so will leave that to someone else. Content negotiation can be initiated by the document author (in the case that multiple alternatives are explicitly offered in the link to the resource), by the client (in the case of accept headers) or by the HTTP server (in the case of 'multiple choices' response code). Discussion of different MIME types for things written in XML should bear these considerations in mind, as well as the case where the content is already sent and one is trying to dispatch it appropriately. -- Chris > > Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA14303 for ietf-xml-mime-bks; Thu, 8 Apr 1999 05:01:46 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA14298; Thu, 8 Apr 1999 05:01:44 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA14889; Thu, 8 Apr 1999 08:02:28 -0400 Message-ID: <370C9A49.6B08A7AD@w3.org> Date: Thu, 08 Apr 1999 14:00:09 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Paul Hoffman / IMC CC: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <199904070641.AA00216@archlute.apsdc.ksp.fujixerox.co.jp> <4.2.0.32.19990407092004.00b50c00@mail.imc.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Paul Hoffman / IMC wrote: > > Dispatching based on media types raises a few important issues that are > somewhat unique to XML. > > If we say "every application gets a new media type" then there is no clean > way for a MIME-handling application to fall back to handing an unknown > media type to an XML parser. Although that is the right thing to do in some circumstances, and not in others. > An unclean way for such an application to > handle an unknown media type is to look inside the first few octets of the > body and, if it looks like XML, hand it off to the XML parser instead of > treating it as application/octet-stream or text/plain. Increasingly, many programs contain an XML parser. XML is being used for a very wide variety of different things. There is unlikely to be "a" single XML parser - its a component of some other application program. > If we say "stick everything XMLish under a media type that is XML-specific > with some parameter for the kind of XML" then we assume that handing off > unknown body types to an XML parser is useful. Right. In some cases, it may be. The thing to avoid, though, it to havce to parse the document once to find out what sort of thing it is, dispatch it somewhere else, and then have that "somewhere else" start parsing again from scratch. If that can be avoided by better labelling up front, that is a win. > I question this assumption. Right. > What's the XML parser going to do with this block of data? Display it? Not > terribly valuable. Not even possible, in some cases. XML is being used for all sorts of things from serialising Java Beans to Web server configuration files to interprocess communication - a lot of these uses are not especially "displayable". In some cases, the fact that they are written in XML is the least important thing about them. These are likely to need specialised registrations, too. Further, if the specification for any such case is not controlled by a single vendor, then registration in the vendor tree does not seem appropriate. This would be the case for situations ranging from a small vendor group (such as the Flashpix group) through groups such as W3C to bodies such as ISO, ITU, IEE and so on. Then there is a second class of uses which are essentially textual, where the XML markup is being used to structure headings, footnotes, chapters and suchlike document-like things. These things do indeed benefit, if not recognised, from being "displayed" and may even contain an internal link to a stylesheet which can be used to display them. I think that dispatching this 'marked up text' class of uses to a single parser/viewer, such as a browser, make sense (not in all cases of course, and editing should be distinguished from viewing, but full mailcap files can do that) and thus, a MIME labelling of text/xml would make sense. The third class of uses which are intended to be displayed but which requitre specialised display processors. Examples of these are markup for chemical structures, X3D for xml-ised vrml, PDB (protein database) format, BSML (bioinformatics sequence markup language), SVG (scalable vector graphics) and so on. These are likely to benefit from specialised registrations, which might be in the image, application, model, or other top level types. So far I havewn't seens a good case made for application/xml, sinc ehte re isn't a single XML application; the arguments around its use have centered around concerns for the lowest common denominator fallback to text/plain if text/xml is not recognised (and the possibility of bit 8 mangling, if sent over email rather than http or binary ftp) > Get some namespace information from the inside and then > dispatch based on the namespace? Possibly valuable, but this begs the > question of why wasn't that information out in the MIME headers. > > I tend to lean towards "every application gets a new media type". I think that is reasonable in many cases, but not all. There still seems to be a place for text/xml, for textlike or documentlike applications. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id EAA14176 for ietf-xml-mime-bks; Thu, 8 Apr 1999 04:46:29 -0700 (PDT) Received: from vortex.uplanet.com (host-165-3.uplanet.com [204.163.165.3]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id EAA14172 for ; Thu, 8 Apr 1999 04:46:29 -0700 (PDT) Received: from sluk (t6o49p17.telia.com [195.198.195.77]) by vortex.uplanet.com (8.9.2/8.9.2) with SMTP id EAA11212 for ; Thu, 8 Apr 1999 04:47:11 -0700 (PDT) From: "Peter Stark" To: Subject: Specialised media types (was RE: Starting the ietf-xml-mime mailing list) Date: Thu, 8 Apr 1999 04:47:16 -0700 Message-ID: <000801be81b5$8cda8f30$4dc3c6c3@uplanet.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2377.0 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 In-Reply-To: <01J9R8JTQTIK8WWG0C@INNOSOFT.COM> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I think that using specialized media types - one for every XML app - can be a potential scalability problem. Even if the media type registration is impressively fast today (one day!), I anyway doubt that it's appropriate to have a central authoritive for this purpose. One particular problem is the naming of media types in the Vendor tree: text/vnd.* You can put whatever you like after 'vnd', and that's what people do. I wonder why media types can't use similar naming rules as, for example, java classes (domain names) or XML names (URIs). Wouldn't it be possible to, in some way, join the MIME Media type tree with the domain names. For example, text/xml.org.w3.html, would be XHTML and text/xml.com.anyCo.myXmlApplication, would be someone's XML application. but text/html, would still be HTML That way, the browser can, even if it doesn't recognize the type, at least see that it's an XML document (and perhaps display it). It also means that I can create my own media types without having to contact a central naming authority (except for getting the domain name). I can also further sub-type my own media type. Perhaps some sort of new URN should be used instead, I don't know. Anything would be better than "vnd.whatever.."-names. PS > -----Original Message----- > From: owner-ietf-xml-mime@imc.org [mailto:owner-ietf-xml-mime@imc.org]On > Behalf Of Ned Freed > Sent: Wednesday, April 07, 1999 3:11 PM > To: Larry Masinter > Cc: Earthlink; ietf-xml-mime@imc.org > Subject: RE: Starting the ietf-xml-mime mailing list > > > > > In addition, though, we also want to get at subtypes of > objects. Or in the > > > case of MIME type/subtypes, this would be the "sub-sub type". > For example, > > > for a calendar object (text/calendar) we want to pull to the > client just the > > > "event invitations". This would be the "sub sub type" of type=text, > > > subtype=calendar. > > > This is a good example of a problem that specialized media > types won't solve. > > Agreed. > > My quick and dirty way of thinking of this is that the media type/subtype > should to be sufficient to get you the right application, but the > parameters > then can tell that application what to do, or when to do it, or > various other > sorts of things that for whatever reason are best not stored in > or derived from > the actual content. > > > You might also want to scan your email for "event invitations > from my boss", > > and you can't solve that problem with specialized MIME media > types. So the > > question is: are there any realistic cases where having a > "text/calendar" > > distinction in the email header actually helps substantially in deciding > > which email bodies to retrieve? > > Of course the general case of this problem may in fact be > intractable, even > with full access to message content. (Define "boss". Figure out > how to relate > the origin of a given event invitation to this definition of "boss". Etc.) > However, in the general problem space surrounding these sorts of > applications, > I see value in using parameters. For example, I may wish to have certain > sorts of calendar operations handled silently and automatically, whereas > others need to be done manually. > > In short, I agree with Frank that parameters have their uses in > this context. > > Ned > > Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id EAA13970 for ietf-xml-mime-bks; Thu, 8 Apr 1999 04:23:34 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id EAA13966 for ; Thu, 8 Apr 1999 04:23:33 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id HAA12250; Thu, 8 Apr 1999 07:24:15 -0400 Message-ID: <370A8FB6.64B32EEB@w3.org> Date: Wed, 07 Apr 1999 00:50:30 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: "Donald E. Eastlake 3rd" CC: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <199904062050.QAA02470@torque.pothole.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: "Donald E. Eastlake 3rd" wrote: > > I consider the original question to have been pretty insulting. OK, I accept that you consider it so; it wasn't intended to be, and Paul Hoffman seemed to treat it like a simple request for information and responded with that information. > There > is only one set of MIME types for all uses. That is also my understanding; I was checking that this is shared and agreed upon context for this discussion. I have heard other opinions voice the contrary. > The name of the list is > ietf-xml-mime, not email-xml-mime. Right, so we are clear it is about MIME; and if we read the MIME RFCs we are clear that that MIME is about email, and not necessarily clear that it is about any other protocol. So it seemed better to ask at first than to risk misunderstandings because of a lack of shared assumptions. > If it had been hosted at the W3C, > would non-web uses have been ignored? Yes, unless they could be shown to follow naturally and pretty much for free from the Web uses. The Web is the universe of network-accessible information. So, that includes mail, ftp, and so on. It struck me as an entirely reasonable question, in particular since the RFC that defines text/xml and application/xml refers to "MIME-like protocols" which seems to imply that HTTP is not MIME (something I have heard asserted in the past). So, if everyone agrees that the scope is, at minimum, both email and HTTP, then we can move on. It never hurts, I find, to state exactly what problem is being solved before attempting to solve it. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id TAA05355 for ietf-xml-mime-bks; Wed, 7 Apr 1999 19:10:50 -0700 (PDT) Received: from sh.w3.mag.keio.ac.jp (sh.w3.mag.keio.ac.jp [133.27.194.41]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id TAA05351 for ; Wed, 7 Apr 1999 19:10:47 -0700 (PDT) Received: from enoshima (ppp0ppp66.sfc.keio.ac.jp [133.27.13.87]) by sh.w3.mag.keio.ac.jp (8.9.0/3.6W-W3C/Keio) with SMTP id LAA07387; Thu, 8 Apr 1999 11:11:21 +0900 (JST) Message-Id: <199904080211.LAA07387@sh.w3.mag.keio.ac.jp> X-Sender: duerst@sh.w3.mag.keio.ac.jp X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3-J (32) Date: Thu, 08 Apr 1999 08:37:00 +0900 To: Paul Grosso From: "Martin J. Duerst" Subject: Re: Starting the ietf-xml-mime mailing list Cc: ietf-xml-mime@imc.org In-Reply-To: <3.0.32.19990407095211.0102b910@pophost.arbortext.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 09:53 99/04/07 -0500, Paul Grosso wrote: > the original namespace proposal > developed by the XML WG was to have namespace declarations only in > the prolog (at the top) of an XML document. > Now there is this suggestion to collect all declared namespaces at > the top of the document again. Isn't this going around in circles? > Whatever the reasons for going with locally scoped declarations, aren't > most of them also reasons against listing all such decls at the top? As the discussion about callendars has just shown, there can be huge differences between having things inside the document (even at the top) and outside ("higher up than the top"). Also, requiring that all used namespaces be listed may definitely be too much in certain scenarios. It could be only the "main" namespace(s), only the "mandatory" namespaces, and so on. That would then of course lead to the question of how to distinguish these cases. Regards, Martin. #-#-# Martin J. Du"rst, World Wide Web Consortium #-#-# mailto:duerst@w3.org http://www.w3.org Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id QAA03689 for ietf-xml-mime-bks; Wed, 7 Apr 1999 16:16:03 -0700 (PDT) Received: from snipe.prod.itd.earthlink.net (snipe.prod.itd.earthlink.net [207.217.120.62]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id QAA03681 for ; Wed, 7 Apr 1999 16:16:02 -0700 (PDT) Received: from fdawson (1Cust85.tnt3.durham.nc.da.uu.net [153.37.239.85]) by snipe.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id QAA15197; Wed, 7 Apr 1999 16:16:41 -0700 (PDT) Message-ID: <04a601be814c$73738240$f95472c6@fdawson.lotus.com> From: "Frank Dawson" To: "Larry Masinter" , Subject: Re: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 19:14:51 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote, in part: >I'm saying you definitely have a problem: you have a complex space >of possible objects: NO, this is not a complex problem. This is an existing 20+ year old mail enabled application. This nut has already been cracked for Internet developers using the "text/calendar" content definition. I queried Kurita-san and Paul Hoffman because I was interested in utilizing XML representation of iCalendar. We have a DTD defined. It is an isomer of the iCalendar standard format, but the MIME content type defintiion for text/xml and application/xml stinks. It doesn't provide us (and soon other XML application developers too) the right tools to do our job. Tools that are already in place for the iCalendar content type. This is not a problem with MIME. This is not a problem with calendaring. This is a problem with the current definition for the XML content type. This mailing list is to air our discussion on how to best fix this, right? >Yes, the example is real, and shows that this problem can't be solved >by overloading the MIME type space. Well, I personally don't think that we have "overloaded" the calendar content type in the iCalendar content type definition. There needs to be some balance between an infinite number of media types/subtypes for each transaction type and a smaller, managable number of media types for each logical application object type. As Ned has pointed out, this example and other show that leaving "hooks" on the outside of the object wrapper is very useful in providing a scalable, practical Internet solution using XML. - - Frank Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id QAA03679 for ietf-xml-mime-bks; Wed, 7 Apr 1999 16:16:01 -0700 (PDT) Received: from snipe.prod.itd.earthlink.net (snipe.prod.itd.earthlink.net [207.217.120.62]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id QAA03675 for ; Wed, 7 Apr 1999 16:15:59 -0700 (PDT) Received: from fdawson (1Cust85.tnt3.durham.nc.da.uu.net [153.37.239.85]) by snipe.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id QAA15147; Wed, 7 Apr 1999 16:16:38 -0700 (PDT) Message-ID: <04a501be814c$7203c5a0$f95472c6@fdawson.lotus.com> From: "Frank Dawson" To: "Larry Masinter" , Subject: Re: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 19:04:48 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: >You might also want to scan your email for "event invitations from my boss", >and you can't solve that problem with specialized MIME media types. So the >question is: are there any realistic cases where having a "text/calendar" >distinction in the email header actually helps substantially in deciding >which email bodies to retrieve? Actually, the current MIME content type definition for "text/calendar" provides for MIME header parameter that CUAs are using to scan the inbox for the "new invitations". This is what gave me concern when I read the content type definition for text/xml and application/xml. It doesn't allow an application to detect what kind of XML object is in the email. For our application area, it is disfunctional. It is imparing the use of XML for representing iCalendar objects (and certainly other application objects too). - - Frank Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id PAA03410 for ietf-xml-mime-bks; Wed, 7 Apr 1999 15:51:29 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id PAA03405; Wed, 7 Apr 1999 15:51:28 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <61701(5)>; Wed, 7 Apr 1999 15:52:10 PDT Received: from copper.parc.xerox.com ([13.1.102.170]) by thelma.parc.xerox.com with SMTP id <101331>; Wed, 7 Apr 1999 15:52:03 PDT From: "Larry Masinter" To: "Earthlink" , , "Paul Hoffman / IMC" Subject: RE: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 15:51:59 PDT Message-ID: <000401be8149$3e82ae60$aa66010d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Importance: Normal In-reply-to: <039d01be8143$694257a0$f95472c6@fdawson.lotus.com> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I'm saying you definitely have a problem: you have a complex space of possible objects: "all possible calendaring events, with indication as to the applicable users, the nature of the event, whether it's a request, a response, the dates involved, urgent" You need to query this space, find those that match a particular set of criteria, and then retrieve the objects that match your criteria. Neither adding parameters to text/calendar nor inventing new MIME subtypes for text/calendar-request text/calendar-response etc. will help implement the query capabilities that you need. Since it doesn't work, stop trying. You need some other kind of query protocol than keying off content-type. > However, just having a "calendar" media type won't cut it. The CUA needs to > be able to search the MIME entity bucket for particular types of "calendar" > media types. No, I think this is a poor characterization. The CUA needs to be able to search the MIME entity bucket for particular calendar events that match a particular query, "all repeating events that do not occur on Thursday". Trying to cram this into the type space is just poor engineering. Yes, it needs to search the MIME entity bucket. No, the search is not characterized by "type". > All of these scheduling messages "sub-sub types" are represented in the same > single calendar media type. You may want to characterize them as "sub-sub types", but it is a misuse of the type space. > Tell me again, how you are going a scalable way > for a "calendar portal" site that has 100s of thousands of calendar users > wanting this info each day to service requests from CUAs for "new > invitations" or "invitation responses"? You can't expect the calendar > service to be able to parse ALL of the thousands of XML entities that are in > the MIME entity bucket to first find the calendar ones and then the "new > invitations" or "invitation responses". Someone has to parse them. Certainly if a search engine can parse web pages to find the words and their lexical equivalences, an event search engine can parse the XML documents and index them in the multiple ways that searching the calendar-event database needs to be searched. > If calendaring doesn't provide a real enough example, Yes, the example is real, and shows that this problem can't be solved by overloading the MIME type space. > think about electronic > commerce and the millions of transactions a site may be handling a day. We > can't expect an EDI client to have to parse each of the XML entities in the > MIME bucket to find the "purchase orders". Purchase orders that are applicable to the particular division, purchase orders that haven't already been processed, purchase orders that are assigned to a particular account rep, etc. These are all database search problems, not type-indexing problems. Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id PAA03109 for ietf-xml-mime-bks; Wed, 7 Apr 1999 15:19:05 -0700 (PDT) Received: from THOR.INNOSOFT.COM (SYSTEM@THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id PAA03105 for ; Wed, 7 Apr 1999 15:19:04 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9R3FOYCR48WWG0C@INNOSOFT.COM> for ietf-xml-mime@imc.org; Wed, 7 Apr 1999 15:17:37 PDT Date: Wed, 07 Apr 1999 15:10:31 -0700 (PDT) From: Ned Freed Subject: RE: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Wed, 07 Apr 1999 14:56:06 -0700 (PDT)" <002401be8141$6fe9c040$aa66010d@copper.parc.xerox.com> To: Larry Masinter Cc: Earthlink , ietf-xml-mime@imc.org Message-id: <01J9R8JTQTIK8WWG0C@INNOSOFT.COM> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 References: <033901be813f$a7ace040$f95472c6@fdawson.lotus.com> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > > In addition, though, we also want to get at subtypes of objects. Or in the > > case of MIME type/subtypes, this would be the "sub-sub type". For example, > > for a calendar object (text/calendar) we want to pull to the client just the > > "event invitations". This would be the "sub sub type" of type=text, > > subtype=calendar. > This is a good example of a problem that specialized media types won't solve. Agreed. My quick and dirty way of thinking of this is that the media type/subtype should to be sufficient to get you the right application, but the parameters then can tell that application what to do, or when to do it, or various other sorts of things that for whatever reason are best not stored in or derived from the actual content. > You might also want to scan your email for "event invitations from my boss", > and you can't solve that problem with specialized MIME media types. So the > question is: are there any realistic cases where having a "text/calendar" > distinction in the email header actually helps substantially in deciding > which email bodies to retrieve? Of course the general case of this problem may in fact be intractable, even with full access to message content. (Define "boss". Figure out how to relate the origin of a given event invitation to this definition of "boss". Etc.) However, in the general problem space surrounding these sorts of applications, I see value in using parameters. For example, I may wish to have certain sorts of calendar operations handled silently and automatically, whereas others need to be done manually. In short, I agree with Frank that parameters have their uses in this context. Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id PAA03021 for ietf-xml-mime-bks; Wed, 7 Apr 1999 15:11:20 -0700 (PDT) Received: from robin.prod.itd.earthlink.net (robin.prod.itd.earthlink.net [207.217.120.65]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id PAA03016; Wed, 7 Apr 1999 15:11:19 -0700 (PDT) Received: from fdawson (1Cust149.tnt2.durham.nc.da.uu.net [153.37.238.149]) by robin.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id PAA19792; Wed, 7 Apr 1999 15:11:56 -0700 (PDT) Message-ID: <039d01be8143$694257a0$f95472c6@fdawson.lotus.com> From: "Earthlink" To: , "Paul Hoffman / IMC" Subject: Re: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 18:10:11 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I think that this argument needs a realworld application to give it some bite. I really don't think that there is appreciation for the problem facing application developers who are looking at possibly using a XML representation for their object, but are frustrated with the current MIME definition for the XML content type. Paul Hoffman wrote: >I tend to lean towards "every application gets a new media type". Paul understand the calendaring and scheduling application about as well as any outsider to this application domain. I agree with his note that argues that the MIME header needs to provide cues to application-specific client agents (e.g., Calendar User Agent) that periodically peeks into the MIME entity bucket (e.g., inbox) to look for it's application specific messages. This is the paradigm that mail-enabled CUAs use today. However, just having a "calendar" media type won't cut it. The CUA needs to be able to search the MIME entity bucket for particular types of "calendar" media types. Some of the ones that the Internet community has standardized in RFC 2447 include: EVENT PUBLISH (publish some arbitrary calendar data) EVENT REQUEST (initial invitation, reschedule, delegate the invitation, response to a counter-proposal) EVENT REPLY (response to an invitation) EVENT CANCEL (cancel the meeting or uninvite a single individual) EVENT ADD (add a set of additional instances to an already scheduled event) EVENT COUNTER (proposal an alternate time/place) EVENT DECLINECOUNTER (decline a counter) EVENT REFRESH (now, tell me the latest details for this meeting I am invited to) TODO PUBLISH (publish an arbitrary set of action items) TODO REQUEST TODO REPLY TODO CANCEL TODO ADD TODO COUNTER TODO DECLINE COUNTER TODO REFRESH JOURNAL PUBLISH JOURNAL REQUEST JOURNAL REPLY JOURNAL CANCEL JOURNAL ADD JOURNAL REFRESH A typical CUA action is to look into the MIME entity bucket for new invitations. All of these scheduling messages "sub-sub types" are represented in the same single calendar media type. Tell me again, how you are going a scalable way for a "calendar portal" site that has 100s of thousands of calendar users wanting this info each day to service requests from CUAs for "new invitations" or "invitation responses"? You can't expect the calendar service to be able to parse ALL of the thousands of XML entities that are in the MIME entity bucket to first find the calendar ones and then the "new invitations" or "invitation responses". If calendaring doesn't provide a real enough example, think about electronic commerce and the millions of transactions a site may be handling a day. We can't expect an EDI client to have to parse each of the XML entities in the MIME bucket to find the "purchase orders". - - Frank Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id OAA02847 for ietf-xml-mime-bks; Wed, 7 Apr 1999 14:55:50 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id OAA02843 for ; Wed, 7 Apr 1999 14:55:49 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <61525(2)>; Wed, 7 Apr 1999 14:56:26 PDT Received: from copper.parc.xerox.com ([13.1.102.170]) by thelma.parc.xerox.com with SMTP id <101260>; Wed, 7 Apr 1999 14:56:15 PDT From: "Larry Masinter" To: "Earthlink" , Subject: RE: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 14:56:06 PDT Message-ID: <002401be8141$6fe9c040$aa66010d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 In-Reply-to: <033901be813f$a7ace040$f95472c6@fdawson.lotus.com> Importance: Normal Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > >It's not clear that specialized media types solve any problem at all, > >in the case of XML that already contains a document declaration. > Ned corrected me. There are *some* problems that might be solved by specialized media types. > The overhead of having to open up every XML document to find out what > document type it is is not practical. As in the case of email, all I should > have to do is ask for a particular type of object from the store and get it. > > In addition, though, we also want to get at subtypes of objects. Or in the > case of MIME type/subtypes, this would be the "sub-sub type". For example, > for a calendar object (text/calendar) we want to pull to the client just the > "event invitations". This would be the "sub sub type" of type=text, > subtype=calendar. This is a good example of a problem that specialized media types won't solve. You might also want to scan your email for "event invitations from my boss", and you can't solve that problem with specialized MIME media types. So the question is: are there any realistic cases where having a "text/calendar" distinction in the email header actually helps substantially in deciding which email bodies to retrieve? Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id OAA02742 for ietf-xml-mime-bks; Wed, 7 Apr 1999 14:44:21 -0700 (PDT) Received: from robin.prod.itd.earthlink.net (robin.prod.itd.earthlink.net [207.217.120.65]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id OAA02738 for ; Wed, 7 Apr 1999 14:44:20 -0700 (PDT) Received: from fdawson (1Cust149.tnt2.durham.nc.da.uu.net [153.37.238.149]) by robin.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id OAA04526; Wed, 7 Apr 1999 14:45:02 -0700 (PDT) Message-ID: <033901be813f$a7ace040$f95472c6@fdawson.lotus.com> From: "Earthlink" To: "Larry Masinter" , Subject: Re: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 17:43:13 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: >It's not clear that specialized media types solve any problem at all, >in the case of XML that already contains a document declaration. The overhead of having to open up every XML document to find out what document type it is is not practical. As in the case of email, all I should have to do is ask for a particular type of object from the store and get it. In addition, though, we also want to get at subtypes of objects. Or in the case of MIME type/subtypes, this would be the "sub-sub type". For example, for a calendar object (text/calendar) we want to pull to the client just the "event invitations". This would be the "sub sub type" of type=text, subtype=calendar. - - Frank Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id OAA02717 for ietf-xml-mime-bks; Wed, 7 Apr 1999 14:41:11 -0700 (PDT) Received: from THOR.INNOSOFT.COM (SYSTEM@THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id OAA02713 for ; Wed, 7 Apr 1999 14:41:11 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9R3FOYCR48WWG0C@INNOSOFT.COM> for ietf-xml-mime@imc.org; Wed, 7 Apr 1999 14:40:06 PDT Date: Wed, 07 Apr 1999 14:36:03 -0700 (PDT) From: Ned Freed Subject: RE: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Wed, 07 Apr 1999 12:37:52 -0700 (PDT)" <199904071937.MAA15419@mehitabel.eng.sun.com> To: Murray Altheim Cc: masinter@parc.xerox.com, Ned.Freed@INNOSOFT.COM, murata@apsdc.ksp.fujixerox.co.jp, ietf-xml-mime@imc.org Message-id: <01J9R78BH7ZS8WWG0C@INNOSOFT.COM> MIME-version: 1.0 Content-type: TEXT/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > > > It's not clear that specialized media types solve any problem at all, > > > in the case of XML that already contains a document declaration. > > > > On the contrary, it is very clear that they do solve at least some set of > > problems. There is no explanation for the large numbers of people happily > > registering these things otherwise. We have ample experience to tell us that > > people won't bother with this sort of administration unless they see some > > possible advantage to doing it, and won't continue to do it unless those > > advantages turn out to be real. > On the contrary, there may be a very plausible reason why 'large numbers of > people' are registering specialized media types: there is no suitable > alternative that is supported by the browser vendors at large. There may > be very real advantages in an organized content negotiation scheme, but > they can't be realized if there is no vendor support. I don't believe that > resorting to file extensions can possibly be the way of the future. We > all need a better alternative. Murray, it sounds to me like you are agreeing with me, not disagreeing. All I ever claimed was that contrary to Larry's assertion, it is clear that a real problem is being solved by registering various XML-derived types. I never claimed that this is the correct solution to the problem, or that this is the only problem around that needs a solution, or that this wasn't a solution forced by the current characteristics of browsers. And nowhere did I say that file extensions are being used. These are MIME types, not file extensions. Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id OAA02391 for ietf-xml-mime-bks; Wed, 7 Apr 1999 14:07:49 -0700 (PDT) Received: from robin.prod.itd.earthlink.net (robin.prod.itd.earthlink.net [207.217.120.65]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id OAA02382 for ; Wed, 7 Apr 1999 14:07:48 -0700 (PDT) Received: from fdawson (1Cust149.tnt2.durham.nc.da.uu.net [153.37.238.149]) by robin.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id OAA16154; Wed, 7 Apr 1999 14:08:28 -0700 (PDT) Message-ID: <014001be813a$8dea9580$f95472c6@fdawson.lotus.com> From: "Earthlink" To: "Larry Masinter" , Subject: Re: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 17:06:47 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: >Many current implementations of content dispatch don't allow dispatch >based on media type parameters, in any case. E.g., you can't select >one handler for "text/plain;charset=us-ascii" and a different one >for "text/plain;charset=utf8", even though you might have a more >desirable ascii-only editor and a slower or fuller Unicode-based >editor installed. So adding more parameters doesn't really help >for content-dispatch with current implementations. I think you may be thinking about HTTP? Certainly with a mail protocol like IMAP you can look through your inbox for entries based on values of the MIME header fields. The example mentioned was a "mail-enabled" application. For this application, the implementors on the IETF CALSCH WG felt very much that the MIME header field parameters were of importance. If your implementation doesn't want to make use of them, fine. But other applications of this MIME content-type need it. That is the point. - - Frank Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id OAA02339 for ietf-xml-mime-bks; Wed, 7 Apr 1999 14:03:40 -0700 (PDT) Received: from robin.prod.itd.earthlink.net (robin.prod.itd.earthlink.net [207.217.120.65]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id OAA02335 for ; Wed, 7 Apr 1999 14:03:39 -0700 (PDT) Received: from fdawson (1Cust149.tnt2.durham.nc.da.uu.net [153.37.238.149]) by robin.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id OAA10209; Wed, 7 Apr 1999 14:04:15 -0700 (PDT) Message-ID: <013b01be8139$f7056f00$f95472c6@fdawson.lotus.com> From: "Earthlink" To: "Larry Masinter" , Subject: Re: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 17:02:34 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Massinter wrote, in part: >In general, you cannot solve the problem of "dispatch to the appropriate >handler" by modifying MIME, since finding the appropriate handler is >platform and installation dependent. I don't think that MIME is broken. What was poorly thought out was the content-type definition for XML. - - Frank Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id MAA01775 for ietf-xml-mime-bks; Wed, 7 Apr 1999 12:55:10 -0700 (PDT) Received: from spm.themacs.com (spm.themacs.com [209.98.204.130]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id MAA01767 for ; Wed, 7 Apr 1999 12:55:08 -0700 (PDT) Received: from themacs.com (spmdesktop.themacs.com [209.98.204.131]) by spm.themacs.com (8.8.5/8.8.5) with ESMTP id OAA13654; Wed, 7 Apr 1999 14:55:50 -0500 Message-ID: <370BB84E.E0D9F051@themacs.com> Date: Wed, 07 Apr 1999 14:55:58 -0500 From: "Shane P. McCarron" Reply-To: shane@themacs.com Organization: MACS, Inc. X-Mailer: Mozilla 4.5 [en] (X11; I; Linux 2.2.4 i686) X-Accept-Language: en MIME-Version: 1.0 To: Murray Altheim CC: shane@themacs.com, ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <199904071921.MAA15409@mehitabel.eng.sun.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Murray Altheim wrote: > > Shane P. McCarron writes: > [...] > > In case it isn't obvious, I too lean toward each application "family" > > having their own media type. This is the only broadly recognized > > announcement mechanism we have, after all. > > In thinking about this more, I can see the value in defining a new > media type 'text/xhtml' for the family iff we see that all applications > within that space using the same infrastructure and mechanisms for > extensibility, so that any application within that space can predict > how to read what has been extended and the implications of the > extension. We *may* be able to solve that with document profiles. > > But if it's still open season within 'text/xhtml' then we've only put > off the problem until later, and also compounded it by meaninglessly > fragmented the 'text/xml' space. If there is a solution for XML it > should be the same as for XHTML, and so my sense is that either the > HTML WG's concept of document profiles is more usable generally in > XML or we're duplicating what must also be done for XML. Maybe the way to look at it is that the HTML WG is working in a space and developing a solution that MAY scale to be a general solution. However, the HTML space needs the solution now and we are in a good position to define the solution for the generic HTML-oriented client space. I realize that it would be great if we could define a generic solution for all XML documents, but I just don't see it happening quickly. I think that we can get an HTML-oriented solution ready in uni time (before the end of the year), and I think that it will be a solution that is readily implementable by our constituents (the wireless, television, and desktop client manufacturers). This would be a good thing. -- Shane P. McCarron phone: +1 612 434-4431 Testing Research Manager fax: +1 612 434-4318 mobile: +1 612 799-6942 e-mail: shane@themacs.com OSF/1, Motif, UNIX and the "X" device are registered trademarks in the US and other countries, and IT DialTone and The Open Group are trademarks of The Open Group. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id MAA01660 for ietf-xml-mime-bks; Wed, 7 Apr 1999 12:37:52 -0700 (PDT) Received: from mercury.Sun.COM (mercury.Sun.COM [192.9.25.1]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id MAA01656 for ; Wed, 7 Apr 1999 12:37:51 -0700 (PDT) Received: from engmail2.Eng.Sun.COM ([129.146.1.25]) by mercury.Sun.COM (8.9.3+Sun/8.9.3) with ESMTP id MAA09046; Wed, 7 Apr 1999 12:38:17 -0700 (PDT) Received: from mehitabel.eng.sun.com (mehitabel.Eng.Sun.COM [129.146.82.247]) by engmail2.Eng.Sun.COM (8.8.8+Sun/8.8.8/ENS_USDOMAIN,v%I%) with SMTP id MAA21713; Wed, 7 Apr 1999 12:38:13 -0700 (PDT) Received: from mehitabel by mehitabel.eng.sun.com (SMI-8.6/SMI-SVR4) id MAA15419; Wed, 7 Apr 1999 12:37:53 -0700 Message-Id: <199904071937.MAA15419@mehitabel.eng.sun.com> Date: Wed, 7 Apr 1999 12:37:52 -0700 (PDT) From: Murray Altheim Reply-To: Murray Altheim Subject: RE: Starting the ietf-xml-mime mailing list To: masinter@parc.xerox.com, Ned.Freed@INNOSOFT.COM Cc: murata@apsdc.ksp.fujixerox.co.jp, ietf-xml-mime@imc.org MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: hFcbeW7n+Sv4FmQE4dMaFw== X-Mailer: dtmail 1.2.0 CDE Version 1.2 SunOS 5.6 sun4u sparc Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Ned Freed writes: > Larry Masinter writes: > > MURATA Makoto wrote: > > > > > Are you also against specialized media types? Or, you would like > > > to make clear that specialized media types do not solve all problems? > > > It's not clear that specialized media types solve any problem at all, > > in the case of XML that already contains a document declaration. > > On the contrary, it is very clear that they do solve at least some set of > problems. There is no explanation for the large numbers of people happily > registering these things otherwise. We have ample experience to tell us that > people won't bother with this sort of administration unless they see some > possible advantage to doing it, and won't continue to do it unless those > advantages turn out to be real. On the contrary, there may be a very plausible reason why 'large numbers of people' are registering specialized media types: there is no suitable alternative that is supported by the browser vendors at large. There may be very real advantages in an organized content negotiation scheme, but they can't be realized if there is no vendor support. I don't believe that resorting to file extensions can possibly be the way of the future. We all need a better alternative. Murray ........................................................................... Murray Altheim, SGML Grease Monkey Member of Technical Staff, Tools Development & Support Sun Microsystems, 901 San Antonio Rd., UMPK17-102, Palo Alto, CA 94303-4900 An SGML declaration does not an i18n make. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id MAA01506 for ietf-xml-mime-bks; Wed, 7 Apr 1999 12:21:37 -0700 (PDT) Received: from mercury.Sun.COM (mercury.Sun.COM [192.9.25.1]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id MAA01502 for ; Wed, 7 Apr 1999 12:21:37 -0700 (PDT) Received: from engmail2.Eng.Sun.COM ([129.146.1.25]) by mercury.Sun.COM (8.9.3+Sun/8.9.3) with ESMTP id MAA01590; Wed, 7 Apr 1999 12:22:18 -0700 (PDT) Received: from mehitabel.eng.sun.com (mehitabel.Eng.Sun.COM [129.146.82.247]) by engmail2.Eng.Sun.COM (8.8.8+Sun/8.8.8/ENS_USDOMAIN,v%I%) with SMTP id MAA18545; Wed, 7 Apr 1999 12:22:15 -0700 (PDT) Received: from mehitabel by mehitabel.eng.sun.com (SMI-8.6/SMI-SVR4) id MAA15409; Wed, 7 Apr 1999 12:21:56 -0700 Message-Id: <199904071921.MAA15409@mehitabel.eng.sun.com> Date: Wed, 7 Apr 1999 12:21:56 -0700 (PDT) From: Murray Altheim Reply-To: Murray Altheim Subject: Re: Starting the ietf-xml-mime mailing list To: shane@themacs.com Cc: ietf-xml-mime@imc.org MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: qvvvvt5gfmBJt1skw6QDkA== X-Mailer: dtmail 1.2.0 CDE Version 1.2 SunOS 5.6 sun4u sparc Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Shane P. McCarron writes: [...] > In case it isn't obvious, I too lean toward each application "family" > having their own media type. This is the only broadly recognized > announcement mechanism we have, after all. In thinking about this more, I can see the value in defining a new media type 'text/xhtml' for the family iff we see that all applications within that space using the same infrastructure and mechanisms for extensibility, so that any application within that space can predict how to read what has been extended and the implications of the extension. We *may* be able to solve that with document profiles. But if it's still open season within 'text/xhtml' then we've only put off the problem until later, and also compounded it by meaninglessly fragmented the 'text/xml' space. If there is a solution for XML it should be the same as for XHTML, and so my sense is that either the HTML WG's concept of document profiles is more usable generally in XML or we're duplicating what must also be done for XML. Murray ........................................................................... Murray Altheim, SGML Grease Monkey Member of Technical Staff, Tools Development & Support Sun Microsystems, 901 San Antonio Rd., UMPK17-102, Palo Alto, CA 94303-4900 An SGML declaration does not an i18n make. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id MAA01417 for ietf-xml-mime-bks; Wed, 7 Apr 1999 12:12:12 -0700 (PDT) Received: from THOR.INNOSOFT.COM (SYSTEM@THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id MAA01413 for ; Wed, 7 Apr 1999 12:12:10 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9R0MO501S8WWG0C@INNOSOFT.COM> for ietf-xml-mime@imc.org; Wed, 7 Apr 1999 12:11:46 PDT Date: Wed, 07 Apr 1999 12:07:42 -0700 (PDT) From: Ned Freed Subject: RE: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Tue, 06 Apr 1999 23:58:49 -0700 (PDT)" <001d01be80c4$1681c020$79d3000d@copper.parc.xerox.com> To: Larry Masinter Cc: MURATA Makoto , ietf-xml-mime@imc.org Message-id: <01J9R22E9EKC8WWG0C@INNOSOFT.COM> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 References: <199904070641.AA00216@archlute.apsdc.ksp.fujixerox.co.jp> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > > Are you also against specialized media types? Or, you would like > > to make clear that specialized media types do not solve all problems? > It's not clear that specialized media types solve any problem at all, > in the case of XML that already contains a document declaration. On the contrary, it is very clear that they do solve at least some set of problems. There is no explanation for the large numbers of people happily registering these things otherwise. We have ample experience to tell us that people won't bother with this sort of administration unless they see some possible advantage to doing it, and won't continue to do it unless those advantages turn out to be real. Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id LAA01236 for ietf-xml-mime-bks; Wed, 7 Apr 1999 11:48:44 -0700 (PDT) Received: from THOR.INNOSOFT.COM (THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id LAA01231; Wed, 7 Apr 1999 11:48:41 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9R0MO501S8WWG0C@INNOSOFT.COM>; Wed, 7 Apr 1999 11:47:26 PDT Date: Wed, 07 Apr 1999 11:38:51 -0700 (PDT) From: Ned Freed Subject: RE: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Wed, 07 Apr 1999 10:44:57 -0700 (PDT)" <001301be811e$5a2308c0$aa66010d@copper.parc.xerox.com> To: Larry Masinter Cc: Ned Freed , Paul Hoffman / IMC , ietf-xml-mime@imc.org Message-id: <01J9R178PHF88WWG0C@INNOSOFT.COM> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 References: <01J9QYRR52GS8WW98O@INNOSOFT.COM> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > > > I tend to lean towards "every application gets a new media type". > > > > In case it isn't obvious by now, so do I. > This is a fine maxim, but it begs the question: what constitutes > a separate, distinct application, vs a modification, profile, > extension, or varation of an old one? > In the case where you're allowed to have a document that mixes > traditional HTML, MathML, Vector Graphics ML, etc., are these > separate "applications" or are they one "application" ("renderable > XML document")? But this then begs the more general question of whether there is to be an attempt to "design" the XML usage space, and if there is, whether such an attempt has any chance of succeeding. If the answer to this is "no, we don't want to try and control the development, direction, and use of XML" then your question is basically out of scope. People will design whatever they want and register whatever they want. The resulting mixtures and granularity will be whatever developers decide is appropriate. And in such a world I see little value in having an XML top level type. (Perhaps no real harm, but little value.) However, if the answer to this is "yes", then the task at hand becomes one of coming up with an appropriate set of rules that people think will actually do the job and will be followed. And in such a world a top-level XML type might have some value, if only as a place to attach the ruleset. (Delegation of XML registration would also be something to consider.) I basically don't have an opinion on which way this should go. My one observation is that the IETF at least has typically opted to try and stay out of areas like this in the past. Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id LAA01200 for ietf-xml-mime-bks; Wed, 7 Apr 1999 11:42:27 -0700 (PDT) Received: from spm.themacs.com (spm.themacs.com [209.98.204.130]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id LAA01191; Wed, 7 Apr 1999 11:42:25 -0700 (PDT) Received: from themacs.com (spmdesktop.themacs.com [209.98.204.131]) by spm.themacs.com (8.8.5/8.8.5) with ESMTP id NAA13160; Wed, 7 Apr 1999 13:42:58 -0500 Message-ID: <370BA739.C588519D@themacs.com> Date: Wed, 07 Apr 1999 13:43:05 -0500 From: "Shane P. McCarron" Reply-To: shane@themacs.com Organization: MACS, Inc. X-Mailer: Mozilla 4.5 [en] (X11; I; Linux 2.2.4 i686) X-Accept-Language: en MIME-Version: 1.0 To: Larry Masinter CC: Ned Freed , Paul Hoffman / IMC , ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <001301be811e$5a2308c0$aa66010d@copper.parc.xerox.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: > > > > I tend to lean towards "every application gets a new media type". > > > > In case it isn't obvious by now, so do I. > > This is a fine maxim, but it begs the question: what constitutes > a separate, distinct application, vs a modification, profile, > extension, or varation of an old one? > > In the case where you're allowed to have a document that mixes > traditional HTML, MathML, Vector Graphics ML, etc., are these > separate "applications" or are they one "application" ("renderable > XML document")? Well... The issue is certainly complex. In the XHTML world, we envision a plethora of derivative document types based upon the defined XHTML modules and their semantics, other standard modules and THEIR semantics, and privately defined modules and THEIR semantics. While we are still actively debating the definition of "XHTML Family", it is clear to me that this family includes a significant subset of these derivative document types. So, if there is a type for XHTML (text/xhtml), then that type has to be flexible enough in definition to accommodate all documents with a type that falls within the XHTML family. A Conforming Client would be required to handle any XHTML family document in some sensible manner. So, in answer to your question, I think it is up to the developer of the Media Type to define the rules for inclusion within that type, and to do so carefully. If they do it wrong (as we did in text/html), then they will be forced to live with their error forever. If they do it right, then future documents will forever be compatible in some manner. Viola. Too simple? Perhaps. Too much magic? Perhaps again. However, we are not in a position to dictate what every possible application might do in the future. Better to tell the application developers to be circumspect, and let the market decide who did it right in the end. In case it isn't obvious, I too lean toward each application "family" having their own media type. This is the only broadly recognized announcement mechanism we have, after all. -- Shane P. McCarron phone: +1 612 434-4431 Testing Research Manager fax: +1 612 434-4318 mobile: +1 612 799-6942 e-mail: shane@themacs.com OSF/1, Motif, UNIX and the "X" device are registered trademarks in the US and other countries, and IT DialTone and The Open Group are trademarks of The Open Group. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id KAA00583 for ietf-xml-mime-bks; Wed, 7 Apr 1999 10:44:33 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id KAA00578; Wed, 7 Apr 1999 10:44:33 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <56792(2)>; Wed, 7 Apr 1999 10:45:15 PDT Received: from copper.parc.xerox.com ([13.1.102.170]) by thelma.parc.xerox.com with SMTP id <98986>; Wed, 7 Apr 1999 10:45:05 PDT From: "Larry Masinter" To: "Ned Freed" , "Paul Hoffman / IMC" Cc: Subject: RE: Starting the ietf-xml-mime mailing list Date: Wed, 7 Apr 1999 10:44:57 PDT Message-ID: <001301be811e$5a2308c0$aa66010d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 In-Reply-to: <01J9QYRR52GS8WW98O@INNOSOFT.COM> Importance: Normal Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > > I tend to lean towards "every application gets a new media type". > > In case it isn't obvious by now, so do I. This is a fine maxim, but it begs the question: what constitutes a separate, distinct application, vs a modification, profile, extension, or varation of an old one? In the case where you're allowed to have a document that mixes traditional HTML, MathML, Vector Graphics ML, etc., are these separate "applications" or are they one "application" ("renderable XML document")? Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id KAA00506 for ietf-xml-mime-bks; Wed, 7 Apr 1999 10:37:11 -0700 (PDT) Received: from THOR.INNOSOFT.COM (SYSTEM@THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id KAA00501; Wed, 7 Apr 1999 10:37:09 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9OPMH0SDC8WW98O@INNOSOFT.COM>; Wed, 7 Apr 1999 10:37:41 PDT Date: Wed, 07 Apr 1999 10:27:54 -0700 (PDT) From: Ned Freed Subject: RE: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Wed, 07 Apr 1999 09:28:31 -0700" <4.2.0.32.19990407092004.00b50c00@mail.imc.org> To: Paul Hoffman / IMC Cc: ietf-xml-mime@imc.org Message-id: <01J9QYRR52GS8WW98O@INNOSOFT.COM> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=us-ascii References: <199904070641.AA00216@archlute.apsdc.ksp.fujixerox.co.jp> <001d01be80c4$1681c020$79d3000d@copper.parc.xerox.com> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > Dispatching based on media types raises a few important issues that are > somewhat unique to XML. > If we say "every application gets a new media type" then there is no clean > way for a MIME-handling application to fall back to handing an unknown > media type to an XML parser. An unclean way for such an application to > handle an unknown media type is to look inside the first few octets of the > body and, if it looks like XML, hand it off to the XML parser instead of > treating it as application/octet-stream or text/plain. > If we say "stick everything XMLish under a media type that is XML-specific > with some parameter for the kind of XML" then we assume that handing off > unknown body types to an XML parser is useful. I question this assumption. And I agree. While I have no strong objection to creating a special top-level type for XML-based things, what experience has shown is that fallback strategies of *any* sort tend to be overrated. In almost every case something has messed it up. Either we got the granularity wrong (and I see a very good chance of this happening here given the emergence of alternative forms of XML), or it didn't prove to offer useful functionality, or it simply didn't deploy in the manner in which we envisioned. About the only success story we have, actually, are the image/audio/video top-level types, and while these have worked out tolerably well, their actual value to end users isn't that great. > What's the XML parser going to do with this block of data? Display it? Not > terribly valuable. Get some namespace information from the inside and then > dispatch based on the namespace? Possibly valuable, but this begs the > question of why wasn't that information out in the MIME headers. It is valuable in the case of a developer who wants to fire up an XML editing tool. But let's be real here -- such a person had better be perfectly capable of assigning types to their editor. If they cannot they had best look for a new line of work. > I tend to lean towards "every application gets a new media type". In case it isn't obvious by now, so do I. Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA29910 for ietf-xml-mime-bks; Wed, 7 Apr 1999 09:53:14 -0700 (PDT) Received: from THOR.INNOSOFT.COM (SYSTEM@THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id JAA29906 for ; Wed, 7 Apr 1999 09:53:13 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9OPMH0SDC8WW98O@INNOSOFT.COM> for ietf-xml-mime@imc.org; Wed, 7 Apr 1999 09:53:41 PDT Date: Wed, 07 Apr 1999 09:49:44 -0700 (PDT) From: Ned Freed Subject: Re: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Wed, 07 Apr 1999 15:37:03 +0900" <199904070637.AA00214@archlute.apsdc.ksp.fujixerox.co.jp> To: MURATA Makoto Cc: ietf-xml-mime@imc.org Message-id: <01J9QX87YFAE8WW98O@INNOSOFT.COM> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii References: <01J9NIKKFTKO8WWH73@INNOSOFT.COM> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > > > Each application will be documented by some RFC. > > > > This isn't true. The standards say that RFC documentation is only required for > > registration in the IETF tree, and in practice none of the many registered > > XML-based types have been backed up with RFCs. > I will revise the summary accordingly. Registration in the IETF tree and > that in the vendor tree are quite different. Moreover, relatively few types belong in the IETF tree. > > > Each specialized application will require a new subtype registration, > > > which takes a lot of time and therefore can have long delays. > > > > This isn't true. Registrations now routinely take only a few days if > > they don't contain egregious errors. And we've been known to get them done > > in less than a day in some cases. > Is this in the vendor tree? The registration process is the same (i.e. fast) in *any* tree that currently exists. The slowness associated with the IETF tree has to do with RFC review, which is an entirely separate process from type registration. The only case where I could imagine the registration process being slow is if we delegate registration trees to some other organization that doesn't do it as quickly as we do. However, thus far no such delegation has taken place, so this is an entirely academic point. Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA29855 for ietf-xml-mime-bks; Wed, 7 Apr 1999 09:44:35 -0700 (PDT) Received: from smtp.gatewaymail.net (root@smtp.gatewaymail.net [207.34.179.250]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id JAA29850; Wed, 7 Apr 1999 09:44:34 -0700 (PDT) Received: from a2a00204 (a2a00204.intergate.bconnected.net [209.53.8.6]) by smtp.gatewaymail.net (8.8.7/8.8.7) with SMTP id RAA10561; Wed, 7 Apr 1999 17:43:29 -0700 Message-Id: <3.0.32.19990407094512.00cee720@pop.intergate.bc.ca> X-Sender: tbray@pop.intergate.bc.ca X-Mailer: Windows Eudora Pro Version 3.0 (32) Date: Wed, 07 Apr 1999 09:45:16 -0700 To: Paul Hoffman / IMC , From: Tim Bray Subject: RE: Starting the ietf-xml-mime mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 09:28 AM 4/7/99 -0700, Paul Hoffman / IMC wrote: >Dispatching based on media types raises a few important issues that are >somewhat unique to XML. While I still haven't thought all this through 100%, Paul has a good point. There are two models we're going to see in the real world. 1. something generic gets the XML and parses it 1.a the generic something displays the XML to a human using a stylesheet, possibly with help from other logic for embedded chunks from different namespaces. 1.b the generic something invokes some application. The 1.a example is of course Web browsers (although it seems there are some nasty architectural holes in how you dispatch control for embedded chunks of XML). I have a hard time thinking of a 1.b example. 2. An app gets invoked to deal with a resource that happens to be encoded in XML, and the app uses its built-in XML parser. This case probably wants its own media type; the fact that the encoding is XML is hardly material. Which of these will be more common? I don't think anyone knows. But they are both very plausible and we need to make sure there's a good coherent story either way. -Tim Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA29762 for ietf-xml-mime-bks; Wed, 7 Apr 1999 09:31:00 -0700 (PDT) Received: from aum (ip11.proper.com [165.227.249.11]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id JAA29758 for ; Wed, 7 Apr 1999 09:30:59 -0700 (PDT) Message-Id: <4.2.0.32.19990407092004.00b50c00@mail.imc.org> X-Sender: phoffman@mail.imc.org X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.32 (Beta) Date: Wed, 07 Apr 1999 09:28:31 -0700 To: From: Paul Hoffman / IMC Subject: RE: Starting the ietf-xml-mime mailing list In-Reply-To: <001d01be80c4$1681c020$79d3000d@copper.parc.xerox.com> References: <199904070641.AA00216@archlute.apsdc.ksp.fujixerox.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Dispatching based on media types raises a few important issues that are somewhat unique to XML. If we say "every application gets a new media type" then there is no clean way for a MIME-handling application to fall back to handing an unknown media type to an XML parser. An unclean way for such an application to handle an unknown media type is to look inside the first few octets of the body and, if it looks like XML, hand it off to the XML parser instead of treating it as application/octet-stream or text/plain. If we say "stick everything XMLish under a media type that is XML-specific with some parameter for the kind of XML" then we assume that handing off unknown body types to an XML parser is useful. I question this assumption. What's the XML parser going to do with this block of data? Display it? Not terribly valuable. Get some namespace information from the inside and then dispatch based on the namespace? Possibly valuable, but this begs the question of why wasn't that information out in the MIME headers. I tend to lean towards "every application gets a new media type". --Paul Hoffman, Director --Internet Mail Consortium Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA29570 for ietf-xml-mime-bks; Wed, 7 Apr 1999 09:02:51 -0700 (PDT) Received: from mercury.Sun.COM (mercury.Sun.COM [192.9.25.1]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id JAA29566 for ; Wed, 7 Apr 1999 09:02:50 -0700 (PDT) Received: from engmail1.Eng.Sun.COM ([129.146.1.13]) by mercury.Sun.COM (8.9.3+Sun/8.9.3) with ESMTP id JAA27281; Wed, 7 Apr 1999 09:03:32 -0700 (PDT) Received: from mehitabel.eng.sun.com (mehitabel.Eng.Sun.COM [129.146.82.247]) by engmail1.Eng.Sun.COM (8.8.8+Sun/8.8.8/ENS_USDOMAIN,v%I%) with SMTP id JAA07915; Wed, 7 Apr 1999 09:03:28 -0700 (PDT) Received: from mehitabel by mehitabel.eng.sun.com (SMI-8.6/SMI-SVR4) id JAA15189; Wed, 7 Apr 1999 09:03:08 -0700 Message-Id: <199904071603.JAA15189@mehitabel.eng.sun.com> Date: Wed, 7 Apr 1999 09:03:08 -0700 (PDT) From: Murray Altheim Reply-To: Murray Altheim Subject: XHTML Schemas, Namespace Ids, and Profiles To: ietf-xml-mime@imc.org, pgrosso@arbortext.com MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: 3XW0TK+3SzgClCJO79tTFA== X-Mailer: dtmail 1.2.0 CDE Version 1.2 SunOS 5.6 sun4u sparc Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: [time for a new thread...] Paul Grosso writes: > At 14:35 1999 04 05 +0900, Martin J. Duerst wrote: > >Define one parameter, maybe named "namespaces", that lists, comma-separated, > >all the namespaces used in the document. The DOCTYPE, if present, counts as > >one. The DOCTYPE, or the namespace of the root element, is listed first. > >If other description mechanisms (schemas,...) are defined, the URIs used > >for them can also be used. > > This is extremely ironic given that the original namespace proposal > developed by the XML WG was to have namespace declarations only in > the prolog (at the top) of an XML document. This would have made > lots of things easier, but higher authorities decided that it was > necessary to completely revamp the namespace proposal at the last > minute to give locally scoped namespace declarations. I've long argued that the truly broken part of the current namespace proposal is that the namespace 'declaration' occurs in the instance, and that any sort of multiple-document type schema processing must occur in the prolog, potentially even before the schema/DTD is encountered. For example, if I were to write an application that colonized several DTDs before attempting validation of an instance containing colonized names, I'd need to see the declarations *before* the DTDs. Apparently some do not see the prolog-instance separation as valuable. One of the things I've also been trying to assert in the HTML WG is the separation between the document type definition and the document [instance's] namespace. In documents containing a DOCTYPE the former is provided, and the namespace 'declaration' (damn, I can never quite remove those quotes) provides the namespace identifier. For XHTML, there is essentially one namespace, as regardless of which of the three DTDs (Strict, Transitional, or Frameset) the semantics for understanding and processing a specific element type are identical. One of the HTML WG work items is 'document profiles', some sort of extensible metadata container for information about the document type or instance. This might contain MIME information, further links to schema documentation, author contact info, interoperability data, etc. My thinking is that it would be hierarchical and potentially full of external links, so that applications can dig as deep as necessary for further information. Or simply use either the profile identifier or some node-level sub-identifier as a cookie. We'd for awhile discussed using the existing 'profile' attribute on , but for some reason which I can't recall now have moved away from that (either some people thought that we might not require in all XHTML 'family' doctypes, or that it was overloading the attribute). I do think it better as a separate element type, as this allows containment (and therefore inlining of a profile within a document). My current favorite syntax for linking a profile would borrow ideas from existing HTML stylesheet syntax, allowing for either an inline profile, or a link to an external profile. I think most people would find this intuitively obvious (given experience with stylesheets). Simple processors could use the profile URI as a cookie, or retrieve it to obtain further data. The Cruise of the Jasper B. ... or expanded: The Cruise of the Jasper B. ...TBD... ... The second example still includes the href, to point out the need to create a way to maintain a named identifier for profiles, if such an identifier is ever to be used as a cookie. Perhaps the 'title' attribute or some other means would be better -- just some ideas anyway. Above we see declarations for: (a) the XML declaration (potentially the encoding, etc.) (b) the DTD's name (publicId/FPI/URN) (c) the DTD's location (systemId/URI) (d) the document namespace identifier (as URI) (e) the document stylesheet type and location (URI) (f) the document profile location (URI) and while obviously not all are needed all the time, I can certainly see the ability to maintain this separation being quite valuable. Murray ........................................................................... Murray Altheim, SGML Grease Monkey Member of Technical Staff, Tools Development & Support Sun Microsystems, 901 San Antonio Rd., UMPK17-102, Palo Alto, CA 94303-4900 An SGML declaration does not an i18n make. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id HAA28974 for ietf-xml-mime-bks; Wed, 7 Apr 1999 07:52:34 -0700 (PDT) Received: from sprouts.arbortext.com (root@sprouts.arbortext.com [198.108.59.201]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id HAA28970 for ; Wed, 7 Apr 1999 07:52:32 -0700 (PDT) Message-Id: <3.0.32.19990407095211.0102b910@pophost.arbortext.com> X-Sender: pbg@pophost.arbortext.com X-Mailer: Windows Eudora Pro Version 3.0 (32) Date: Wed, 07 Apr 1999 09:53:13 -0500 To: ietf-xml-mime@imc.org From: Paul Grosso Subject: Re: Starting the ietf-xml-mime mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 14:35 1999 04 05 +0900, Martin J. Duerst wrote: >Define one parameter, maybe named "namespaces", that lists, comma-separated, >all the namespaces used in the document. The DOCTYPE, if present, counts as >one. The DOCTYPE, or the namespace of the root element, is listed first. >If other description mechanisms (schemas,...) are defined, the URIs used >for them can also be used. This is extremely ironic given that the original namespace proposal developed by the XML WG was to have namespace declarations only in the prolog (at the top) of an XML document. This would have made lots of things easier, but higher authorities decided that it was necessary to completely revamp the namespace proposal at the last minute to give locally scoped namespace declarations. Now there is this suggestion to collect all declared namespaces at the top of the document again. Isn't this going around in circles? Whatever the reasons for going with locally scoped declarations, aren't most of them also reasons against listing all such decls at the top? Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id GAA28397 for ietf-xml-mime-bks; Wed, 7 Apr 1999 06:45:08 -0700 (PDT) Received: from smtp.gatewaymail.net (root@smtp.gatewaymail.net [207.34.179.250]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id GAA28392 for ; Wed, 7 Apr 1999 06:45:07 -0700 (PDT) Received: from a2a00204 (a2a00204.intergate.bconnected.net [209.53.8.6]) by smtp.gatewaymail.net (8.8.7/8.8.7) with SMTP id OAA10527; Wed, 7 Apr 1999 14:43:18 -0700 Message-Id: <3.0.32.19990407064311.00cc6a10@pop.intergate.bc.ca> X-Sender: tbray@pop.intergate.bc.ca X-Mailer: Windows Eudora Pro Version 3.0 (32) Date: Wed, 07 Apr 1999 06:45:13 -0700 To: "Larry Masinter" , "MURATA Makoto" , From: Tim Bray Subject: RE: Starting the ietf-xml-mime mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 11:58 PM 4/6/99 PDT, Larry Masinter wrote: >It's not clear that specialized media types solve any problem at all, >in the case of XML that already contains a document declaration. Whereas I may well agree with Larry, I have to raise a red flag in connection with the term "document declaration". XML has something called a "document type declaration" which despite its name essentially gives no useful information about the type of the document or what software ought to be invoked to process it. The new namespace declarations should turn out to be more useful in software dispatching. -Tim Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA27629 for ietf-xml-mime-bks; Wed, 7 Apr 1999 05:25:12 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA27625 for ; Wed, 7 Apr 1999 05:25:10 -0700 (PDT) Received: by mx.fujixerox.co.jp; id VAA21878; Wed, 7 Apr 1999 21:25:52 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma021828; Wed, 7 Apr 99 21:25:35 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id VAA18456 for ; Wed, 7 Apr 1999 21:23:29 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id VAA23737 for ; Wed, 7 Apr 1999 21:25:34 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id VAA12481 for ; Wed, 7 Apr 1999 21:23:35 +0900 Message-Id: <199904071225.AA00227@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Wed, 07 Apr 1999 21:25:24 +0900 To: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <199904071153.UAA00140@sh.w3.mag.keio.ac.jp> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Martin J. Duerst wrote: > > > How can a MIME processor or vCard application extract a vCard fragment > > from the XML document? To do so, somebody has to parse the document. But > > if somebody has to parse it anyway, it should be really easy to find > > which namespace appears in the document. Thus, there is not much point > > in having namespace information in the MIME header. > > If we apply this argument fully, then the doctype is also not necessary. Exactly. I would like to know advantages and disadvantages of Larry's obvious solution (i.e., dispatch to the general-purpose XML parser which further dispatch to appropriate applictions). Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id EAA27383 for ietf-xml-mime-bks; Wed, 7 Apr 1999 04:53:20 -0700 (PDT) Received: from sh.w3.mag.keio.ac.jp (sh.w3.mag.keio.ac.jp [133.27.194.41]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id EAA27371 for ; Wed, 7 Apr 1999 04:53:17 -0700 (PDT) Received: from enoshima (ppp0ppp51.sfc.keio.ac.jp [133.27.13.72]) by sh.w3.mag.keio.ac.jp (8.9.0/3.6W-W3C/Keio) with SMTP id UAA00140; Wed, 7 Apr 1999 20:53:29 +0900 (JST) Message-Id: <199904071153.UAA00140@sh.w3.mag.keio.ac.jp> X-Sender: duerst@sh.w3.mag.keio.ac.jp X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3-J (32) Date: Wed, 07 Apr 1999 16:33:23 +0900 To: MURATA Makoto From: "Martin J. Duerst" Subject: Re: Starting the ietf-xml-mime mailing list Cc: ietf-xml-mime@imc.org In-Reply-To: <199904070631.AA00213@archlute.apsdc.ksp.fujixerox.co.jp> References: <199904050612.PAA02575@sh.w3.mag.keio.ac.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 15:31 99/04/07 +0900, MURATA Makoto wrote: > Martin J. Duerst wrote: > > Define one parameter, maybe named "namespaces", that lists, comma-separated, > > all the namespaces used in the document. The DOCTYPE, if present, counts as > > one. The DOCTYPE, or the namespace of the root element, is listed first. > > If other description mechanisms (schemas,...) are defined, the URIs used > > for them can also be used. > > I am wondering if it is really a good idea to put every information in > the MIME header. Definitely not. > How can a MIME processor or vCard application extract a vCard fragment > from the XML document? To do so, somebody has to parse the document. But > if somebody has to parse it anyway, it should be really easy to find > which namespace appears in the document. Thus, there is not much point > in having namespace information in the MIME header. If we apply this argument fully, then the doctype is also not necessary. I think that, in order to decide which application(s) handle the document, what we have to think about is things such as: - What namespaces are included in the document. - Which of these namespaces have to be understood completely in order to process the document reasonably. - Which of these namespaces can be processed partially, or just ignored. There may be applications that can e.g. only process pure XHTML, or XHTML with some other namespaces, or XHTML with any additional namespaces, and so on. Regards, Martin. #-#-# Martin J. Du"rst, World Wide Web Consortium #-#-# mailto:duerst@w3.org http://www.w3.org Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA16501 for ietf-xml-mime-bks; Tue, 6 Apr 1999 23:58:20 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id XAA16495 for ; Tue, 6 Apr 1999 23:58:19 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <56003(4)>; Tue, 6 Apr 1999 23:58:57 PDT Received: from copper.parc.xerox.com ([13.1.102.170]) by thelma.parc.xerox.com with SMTP id <104002>; Tue, 6 Apr 1999 23:58:56 PDT From: "Larry Masinter" To: "MURATA Makoto" , Subject: RE: Starting the ietf-xml-mime mailing list Date: Tue, 6 Apr 1999 23:58:49 PDT Message-ID: <001d01be80c4$1681c020$79d3000d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 Importance: Normal In-Reply-To: <199904070641.AA00216@archlute.apsdc.ksp.fujixerox.co.jp> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > Are you also against specialized media types? Or, you would like > to make clear that specialized media types do not solve all problems? It's not clear that specialized media types solve any problem at all, in the case of XML that already contains a document declaration. For other situations, specialized media types should be introduced with caution, since a world in which every kind of document has its own media types is one in which there is little interoperability. Larry -- http://www.parc.xerox.com/masinter Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA15933 for ietf-xml-mime-bks; Tue, 6 Apr 1999 23:41:36 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA15927 for ; Tue, 6 Apr 1999 23:41:35 -0700 (PDT) Received: by mx.fujixerox.co.jp; id PAA09370; Wed, 7 Apr 1999 15:42:15 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma009182; Wed, 7 Apr 99 15:41:55 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id PAA14760 for ; Wed, 7 Apr 1999 15:39:50 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id PAA10815 for ; Wed, 7 Apr 1999 15:41:52 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id PAA07538 for ; Wed, 7 Apr 1999 15:39:51 +0900 Message-Id: <199904070641.AA00216@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Wed, 07 Apr 1999 15:41:37 +0900 To: Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <000d01be7f2e$9f23cfa0$79d3000d@copper.parc.xerox.com> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: > As far as I can tell, adding parameters doesn't solve the problem, > and introduces other, possibly more severe, problems. So yes, I'm > arguing against it. Are you also against specialized media types? Or, you would like to make clear that specialized media types do not solve all problems? Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA15796 for ietf-xml-mime-bks; Tue, 6 Apr 1999 23:39:48 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA15792 for ; Tue, 6 Apr 1999 23:39:47 -0700 (PDT) Received: by mx.fujixerox.co.jp; id PAA08580; Wed, 7 Apr 1999 15:40:27 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma008232; Wed, 7 Apr 99 15:39:37 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id PAA13779 for ; Wed, 7 Apr 1999 15:37:31 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id PAA10575 for ; Wed, 7 Apr 1999 15:39:36 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id PAA07528 for ; Wed, 7 Apr 1999 15:37:36 +0900 Message-Id: <199904070639.AA00215@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Wed, 07 Apr 1999 15:39:19 +0900 To: Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <000b01be7f2a$cdef0420$79d3000d@copper.parc.xerox.com> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Larry Masinter wrote: > > > You left out the obvious one: for some kinds of media, it is necessary > for the handler of the MIME media type to actually dispatch to one > of several possible media type handlers. Rather than fixing MIME, > which does the job of labelling data adequately, why not fix the software? Yes, the summary (which was compiled long time ago) dos not have this obvious one. I will add this option. Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA15686 for ietf-xml-mime-bks; Tue, 6 Apr 1999 23:37:30 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA15682 for ; Tue, 6 Apr 1999 23:37:29 -0700 (PDT) Received: by mx.fujixerox.co.jp; id PAA07668; Wed, 7 Apr 1999 15:38:07 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma007438; Wed, 7 Apr 99 15:37:23 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id PAA13074 for ; Wed, 7 Apr 1999 15:35:17 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id PAA10443 for ; Wed, 7 Apr 1999 15:37:22 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id PAA07512 for ; Wed, 7 Apr 1999 15:35:19 +0900 Message-Id: <199904070637.AA00214@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Wed, 07 Apr 1999 15:37:03 +0900 To: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <01J9NIKKFTKO8WWH73@INNOSOFT.COM> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Ned, Thank you for your comments. Freed wrote: > > Each application will be documented by some RFC. > > This isn't true. The standards say that RFC documentation is only required for > registration in the IETF tree, and in practice none of the many registered > XML-based types have been backed up with RFCs. I will revise the summary accordingly. Registration in the IETF tree and that in the vendor tree are quite different. > > Each specialized application will require a new subtype registration, > > which takes a lot of time and therefore can have long delays. > > This isn't true. Registrations now routinely take only a few days if > they don't contain egregious errors. And we've been known to get them done > in less than a day in some cases. Is this in the vendor tree? > > (3) A new parameter "externalid" for text/xml and application/xml ... > I'm afraid you've missed the biggest problem with this approach -- one > that makes it almost a complete nonstarter: The lack of ability to dispatch > on parameters in most applications that support MIME. I will add this fact to the summary. Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA15376 for ietf-xml-mime-bks; Tue, 6 Apr 1999 23:31:16 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA15371 for ; Tue, 6 Apr 1999 23:31:14 -0700 (PDT) Received: by mx.fujixerox.co.jp; id PAA05667; Wed, 7 Apr 1999 15:31:54 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma005472; Wed, 7 Apr 99 15:31:33 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id PAA10067 for ; Wed, 7 Apr 1999 15:29:27 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id PAA10011 for ; Wed, 7 Apr 1999 15:31:30 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id PAA07356 for ; Wed, 7 Apr 1999 15:29:28 +0900 Message-Id: <199904070631.AA00213@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Wed, 07 Apr 1999 15:31:09 +0900 To: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <199904050612.PAA02575@sh.w3.mag.keio.ac.jp> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Martin J. Duerst wrote: I wrote: > > Note: None of the above proposals handle non-monolithic XML documents very well, > > since different islands of non-monolithic XML documents belong to different > > namespaces and thus different schemata. For example, the MIME parser cannot > > invoke vCard applications if the vCard is embeded by the namespace mechanism. > > I think this will become more and more important, and we should try to find > a solution that doesn't exclude it. On first sight, it doesn't look so difficult: > > Define one parameter, maybe named "namespaces", that lists, comma-separated, > all the namespaces used in the document. The DOCTYPE, if present, counts as > one. The DOCTYPE, or the namespace of the root element, is listed first. > If other description mechanisms (schemas,...) are defined, the URIs used > for them can also be used. I am wondering if it is really a good idea to put every information in the MIME header. How can a MIME processor or vCard application extract a vCard fragment from the XML document? To do so, somebody has to parse the document. But if somebody has to parse it anyway, it should be really easy to find which namespace appears in the document. Thus, there is not much point in having namespace information in the MIME header. Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id NAA21989 for ietf-xml-mime-bks; Tue, 6 Apr 1999 13:50:16 -0700 (PDT) Received: from torque.pothole.com ([209.94.126.195]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id NAA21985 for ; Tue, 6 Apr 1999 13:50:15 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by torque.pothole.com (8.8.2/8.8.8) with SMTP id QAA02470 for ietf-xml-mime@imc.org; Tue, 6 Apr 1999 16:50:52 -0400 (EDT) Message-Id: <199904062050.QAA02470@torque.pothole.com> X-Authentication-Warning: torque.pothole.com: localhost [127.0.0.1] didn't use HELO protocol To: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list In-reply-to: Your message of "Tue, 06 Apr 1999 09:47:36 PDT." <4.2.0.32.19990406094521.00bf9800@mail.imc.org> Date: Tue, 06 Apr 1999 16:50:52 -0400 From: "Donald E. Eastlake 3rd" X-Mts: smtp Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I consider the original question to have been pretty insulting. There is only one set of MIME types for all uses. The name of the list is ietf-xml-mime, not email-xml-mime. If it had been hosted at the W3C, would non-web uses have been ignored? Donald From: Paul Hoffman / IMC Message-Id: <4.2.0.32.19990406094521.00bf9800@mail.imc.org> X-Sender: phoffman@mail.imc.org Date: Tue, 06 Apr 1999 09:47:36 -0700 To: Chris Lilley Cc: ietf-xml-mime@imc.org In-Reply-To: <370A020B.8CE866F2@w3.org> References: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> List-Archive: List-Unsubscribe: >At 02:46 PM 4/6/99 +0200, Chris Lilley wrote: >>Given the host of the list (Internet Mail Consortium) > >Hey, we host lists that have little or nothing to do with email (not that I >try to do that too often...) > >> I would like to >>first ask for a clarification; is the topic of discussion *just* the use >>of MIME with XML for email, or does it also include the use of MIME with >>XML for HTTP and any other protocols. > >The latter. > > >--Paul Hoffman, Director >--Internet Mail Consortium Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id JAA19302 for ietf-xml-mime-bks; Tue, 6 Apr 1999 09:47:30 -0700 (PDT) Received: from aum (ip11.proper.com [165.227.249.11]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id JAA19298; Tue, 6 Apr 1999 09:47:28 -0700 (PDT) Message-Id: <4.2.0.32.19990406094521.00bf9800@mail.imc.org> X-Sender: phoffman@mail.imc.org X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.32 (Beta) Date: Tue, 06 Apr 1999 09:47:36 -0700 To: Chris Lilley From: Paul Hoffman / IMC Subject: Re: Starting the ietf-xml-mime mailing list Cc: ietf-xml-mime@imc.org In-Reply-To: <370A020B.8CE866F2@w3.org> References: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 02:46 PM 4/6/99 +0200, Chris Lilley wrote: >Given the host of the list (Internet Mail Consortium) Hey, we host lists that have little or nothing to do with email (not that I try to do that too often...) > I would like to >first ask for a clarification; is the topic of discussion *just* the use >of MIME with XML for email, or does it also include the use of MIME with >XML for HTTP and any other protocols. The latter. --Paul Hoffman, Director --Internet Mail Consortium Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id FAA16258 for ietf-xml-mime-bks; Tue, 6 Apr 1999 05:47:49 -0700 (PDT) Received: from tux.w3.org (root@tux.w3.org [18.29.0.27]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id FAA16253; Tue, 6 Apr 1999 05:47:48 -0700 (PDT) Received: from w3.org (root@localhost [127.0.0.1]) by tux.w3.org (8.8.7/8.8.7) with ESMTP id IAA25909; Tue, 6 Apr 1999 08:48:22 -0400 Message-ID: <370A020B.8CE866F2@w3.org> Date: Tue, 06 Apr 1999 14:46:03 +0200 From: Chris Lilley X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en,fr MIME-Version: 1.0 To: Paul Hoffman / IMC CC: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list References: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Paul Hoffman / IMC wrote: > > OK, we've got about 30 people who signed up for the list. I think the first > order of business is for someone to say what is incorrect and/or lacking in > RFC 2376. Given the host of the list (Internet Mail Consortium) I would like to first ask for a clarification; is the topic of discussion *just* the use of MIME with XML for email, or does it also include the use of MIME with XML for HTTP and any other protocols. -- Chris Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id BAA18288 for ietf-xml-mime-bks; Mon, 5 Apr 1999 01:30:38 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id BAA18284 for ; Mon, 5 Apr 1999 01:30:36 -0700 (PDT) Received: by mx.fujixerox.co.jp; id RAA03231; Mon, 5 Apr 1999 17:31:07 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma003107; Mon, 5 Apr 99 17:30:35 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id RAA17660 for ; Mon, 5 Apr 1999 17:28:29 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id RAA26182 for ; Mon, 5 Apr 1999 17:30:34 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id RAA01715 for ; Mon, 5 Apr 1999 17:28:36 +0900 Message-Id: <199904050830.AA00181@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Mon, 05 Apr 1999 17:30:22 +0900 To: ietf-xml-mime@imc.org Subject: List of issues MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: I compiled a list of issues raised in the past. Although there are seven issues in this list, I would like to concentrate on the first issue for a while. Issue 1: Proposals for additional parameters in the past Namespace URI: It specifies the URI of the top-level namespace of the XML document Schema URI It specifies the URI of the top-level schema of the XML document DTD URI: It specifies the URI of the DTD of the XML document Class URI: It specifies the class of the XML document which will be handled by the same application programs (Note: RDF metadata are XML documents without DTD's, but every RDF metadata can be handled by the same program. XML documents with CSS stylesheets can be displayed by WWW browsers, evenif they do not have DTDs.) Conformance Profile URI: It specifies an XHTML conformance profile. Application URI: It speficies the URI of application programs Root element type: This was suggested as an addition to the namespace/schema/DTD/class URI. Issue 2: Type of XML mime entities There are four types of XML MIME entities. In the XML terminology, they are called "document entities", "external DTD subsets", "external parsed entities", and "external parameter entities". The media types text/xml and application/xml can be used for any of these four types. Do we need some parameter to distinguish these four types? (Note that a MIME entity can be an external parsed entity AND a document entity at the same time. Some external DTD subsets can also be used as external parameter entities.) Issue 3: UTF-16 RFC 2376 should be revised when charsets for UTF-16 are registered. Currently, there is an internet draft for UTF-16 registration. Issue 4: Characters .vs. bytes An XML MIME entity is a sequence of characters as opposed to a sequence of bytes. RFC 2376 is not really clear about this. Issue 5: Packaging There should be a mechanism for packaging an XML document together with its stylesheet, catalog, and referenced resources (e.g., links, external entities). One possibility is MHTML. ftp://ftp.dsv.su.se/users/jpalme/draft-ietf-mhtml-info-11.txt ftp://ftp.dsv.su.se/users/jpalme/draft-ietf-mhtml-rev-07.txt Issue 6: Ambiguity of CCS conversion If an XML document is encoded in some charset whose CCS is not Unicode, XML processors will map the CCS to Unicode. For example, in the case of Shift_JIS, we need a mapping from JIS X 0201 + JIS X0208 to Unicode. Unfortunately, there are more than one mapping in the world. For example, the XML parser of IBM uses Javasoft mapping and that of Javasoft uses Microsoft mapping. I heard that many other charsets have such ambiguities. If this is the case, it might make sense to introduce a parameter "map" to precisely specify which mapping should be used. Issue 7: The default of the charset parameter Chris Lilley's recent proposal to revised RFC2376 is as below: > 1) Require explicit charset for overriding the internal encoding > declaration, so if one really wants to re-label a document as US-ASCII > one actually has to send it out as text/xml; charset="US-ASCII" > > 2) Define the absence of an explicit charset encoding in the MIME > header not as "US-ASCII" but as "use encoding in XML instance" in > accordance with the XML 1.0 Recommendation. Cheers, Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA17578 for ietf-xml-mime-bks; Sun, 4 Apr 1999 23:36:27 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id XAA17574 for ; Sun, 4 Apr 1999 23:36:26 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <52198(5)>; Sun, 4 Apr 1999 23:36:52 PDT Received: from copper.parc.xerox.com ([13.0.211.121]) by thelma.parc.xerox.com with SMTP id <98068>; Sun, 4 Apr 1999 23:36:43 PDT From: "Larry Masinter" To: "Tim Bray" , "MURATA Makoto" , Subject: RE: Starting the ietf-xml-mime mailing list Date: Sun, 4 Apr 1999 23:36:22 PDT Message-ID: <000d01be7f2e$9f23cfa0$79d3000d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-reply-to: <3.0.32.19990404231404.00c716a0@pop.intergate.bc.ca> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > At 11:09 PM 4/4/99 PDT, Larry Masinter wrote: > >In general, you cannot solve the problem of "dispatch to the appropriate > >handler" by modifying MIME, since finding the appropriate handler is > >platform and installation dependent. > > Although you don't say so, I believe you are arguing against the > desirability of an additional media type parameter. Right? -T. As far as I can tell, adding parameters doesn't solve the problem, and introduces other, possibly more severe, problems. So yes, I'm arguing against it. Larry Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA17485 for ietf-xml-mime-bks; Sun, 4 Apr 1999 23:21:54 -0700 (PDT) Received: from THOR.INNOSOFT.COM (SYSTEM@THOR.INNOSOFT.COM [192.160.253.66]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA17481 for ; Sun, 4 Apr 1999 23:21:53 -0700 (PDT) Received: from INNOSOFT.COM by INNOSOFT.COM (PMDF V5.2-32 #30494) id <01J9MVRHLZTC8WWH73@INNOSOFT.COM> for ietf-xml-mime@imc.org; Sun, 4 Apr 1999 23:21:22 PDT Date: Sun, 04 Apr 1999 23:05:23 -0700 (PDT) From: Ned Freed Subject: Re: Starting the ietf-xml-mime mailing list In-reply-to: "Your message dated Mon, 05 Apr 1999 12:33:03 +0900" <199904050333.AA00171@archlute.apsdc.ksp.fujixerox.co.jp> To: MURATA Makoto Cc: ietf-xml-mime@imc.org Message-id: <01J9NIKKFTKO8WWH73@INNOSOFT.COM> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii References: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > (1) Specialized mime types > For each specialized applications of XML, we introduce a new subtype. > It may introduce more parameters and might even have some added > security consideration. This is the approach that has been assumed by > the authors of RFC2376. And it is what is already happening. We've registered several dozen of these already. > Pros: > Each application will be documented by some RFC. This isn't true. The standards say that RFC documentation is only required for registration in the IETF tree, and in practice none of the many registered XML-based types have been backed up with RFCs. > Cons: > When the MIME parser does not know of such a subtype, the only > available fallback is text/plain or application/octet-stream. That > is, the MIME parser cannot invoke generic XML parsers/viewers, but has > to display the document as a plain text file or save the document in a > file. This is a legitimate concern, although in practice what happens is that applications let you assign a viewer to an unknown type in fairly flexible ways. In other words, in practice this isn't all that much of a problem. > Each specialized application will require a new subtype registration, > which takes a lot of time and therefore can have long delays. This isn't true. Registrations now routinely take only a few days if they don't contain egregious errors. And we've been known to get them done in less than a day in some cases. Registrations containing errors take longer, of course. But feedback is quick, typically taking only a day or two, so the burden is on the person doing the registration to turn the thing around in a timely way. > (2) New top-level media type xml and its subtypes > Pros: > Fallback to "xml/plain" allows the use of generic XML parsers/viewers. > We can also lift the line termination rule of the top-level media type > "text". Most XML objects have no business being registered under text anyhow, so this isn't much of an advantage. > Cons: > It is extremely difficult to register a new top-level media type and > therefore can have long delays (practically, who wants to do this?). > The default behavior is probably not a good enough reason. It isn't a question of difficulty, it is a question of legitimacy. To do this you have to write a document that justifies the creation of such a thing. Do so and you likely won't have much of a problem, fail to do so and this approach isn't viable. > Each specialized application will require a new subtype registration, > which takes a lot of time and therefore can have long delays. Again, this just isn't true. > (3) A new parameter "externalid" for text/xml and application/xml > This parameter specifies the externalID from the DOCTYPE of the XML > document (if the DOCTYPE is present). Examples would be: > Content-type: text/xml; > externalid="http://www.foo.com/whizzy.dtd" > or > Content-type: application/xml; charset="utf-16be"; > externalid="-//IETF//DTD vCard v3.0//EN" > Pros: > This is probably the easiest solution which also provides XML-specific > fallback. > Requires no registration with a central authority. > Other parameters can be added in the future when we have new schemata > or when we find new usage patterns for DTDs. The definitions for those > parameters can define which sets of parameters can appear together. > Cons: > ... I'm afraid you've missed the biggest problem with this approach -- one that makes it almost a complete nonstarter: The lack of ability to dispatch on parameters in most applications that support MIME. Not only do applications lack this ability, there are also quite a few contexts where MIME labelling is used that don't support parameters, period. So in all these cases you end up being reduced to a single dispatch path for everything that's based on XML. As I say, its a total nonstarter. > (4) Yet another parameter "optinfo" or "ADD-PARAM" This has all the problems of (3). Ned Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA17453 for ietf-xml-mime-bks; Sun, 4 Apr 1999 23:16:46 -0700 (PDT) Received: from smtp.gatewaymail.net (root@smtp.gatewaymail.net [207.34.179.250]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA17449 for ; Sun, 4 Apr 1999 23:16:46 -0700 (PDT) Received: from a2a00204 (a2a00204.intergate.bconnected.net [209.53.8.6]) by smtp.gatewaymail.net (8.8.7/8.8.7) with SMTP id HAA09706; Mon, 5 Apr 1999 07:15:23 -0700 Message-Id: <3.0.32.19990404231404.00c716a0@pop.intergate.bc.ca> X-Sender: tbray@pop.intergate.bc.ca X-Mailer: Windows Eudora Pro Version 3.0 (32) Date: Sun, 04 Apr 1999 23:17:02 -0700 To: "Larry Masinter" , "MURATA Makoto" , From: Tim Bray Subject: RE: Starting the ietf-xml-mime mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 11:09 PM 4/4/99 PDT, Larry Masinter wrote: >In general, you cannot solve the problem of "dispatch to the appropriate >handler" by modifying MIME, since finding the appropriate handler is >platform and installation dependent. Although you don't say so, I believe you are arguing against the desirability of an additional media type parameter. Right? -T. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA17411 for ietf-xml-mime-bks; Sun, 4 Apr 1999 23:12:09 -0700 (PDT) Received: from sh.w3.mag.keio.ac.jp (sh.w3.mag.keio.ac.jp [133.27.194.41]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id XAA17407 for ; Sun, 4 Apr 1999 23:12:07 -0700 (PDT) Received: from enoshima (dhcp-100-206.mag.keio.ac.jp [133.27.195.206]) by sh.w3.mag.keio.ac.jp (8.9.0/3.6W-W3C/Keio) with SMTP id PAA02575; Mon, 5 Apr 1999 15:12:19 +0900 (JST) Message-Id: <199904050612.PAA02575@sh.w3.mag.keio.ac.jp> X-Sender: duerst@sh.w3.mag.keio.ac.jp X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3-J (32) Date: Mon, 05 Apr 1999 14:35:56 +0900 To: MURATA Makoto From: "Martin J. Duerst" Subject: Re: Starting the ietf-xml-mime mailing list Cc: ietf-xml-mime@imc.org In-Reply-To: <199904050333.AA00171@archlute.apsdc.ksp.fujixerox.co.jp> References: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 12:33 99/04/05 +0900, MURATA Makoto wrote: > Paul Hoffman / IMC wrote: > > OK, we've got about 30 people who signed up for the list. I think the first > > order of business is for someone to say what is incorrect and/or lacking in > > RFC 2376. > > Here it is. I will also post my summary of the discussion at the xml-dev > mailing list very soon. > (3) A new parameter "externalid" for text/xml and application/xml > > This parameter specifies the externalID from the DOCTYPE of the XML > document (if the DOCTYPE is present). Examples would be: > > Content-type: text/xml; > externalid="http://www.foo.com/whizzy.dtd" > or > Content-type: application/xml; charset="utf-16be"; > externalid="-//IETF//DTD vCard v3.0//EN" > Note: None of the above proposals handle non-monolithic XML documents very well, > since different islands of non-monolithic XML documents belong to different > namespaces and thus different schemata. For example, the MIME parser cannot > invoke vCard applications if the vCard is embeded by the namespace mechanism. I think this will become more and more important, and we should try to find a solution that doesn't exclude it. On first sight, it doesn't look so difficult: Define one parameter, maybe named "namespaces", that lists, comma-separated, all the namespaces used in the document. The DOCTYPE, if present, counts as one. The DOCTYPE, or the namespace of the root element, is listed first. If other description mechanisms (schemas,...) are defined, the URIs used for them can also be used. If I'm overlooking something, please tell me. Regards, Martin. #-#-# Martin J. Du"rst, World Wide Web Consortium #-#-# mailto:duerst@w3.org http://www.w3.org Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id XAA17385 for ietf-xml-mime-bks; Sun, 4 Apr 1999 23:09:25 -0700 (PDT) Received: from alpha.xerox.com (firewall-user@alpha.Xerox.COM [13.1.64.93]) by mail.proper.com (8.8.8/8.8.5) with SMTP id XAA17380 for ; Sun, 4 Apr 1999 23:09:20 -0700 (PDT) Received: from thelma.parc.xerox.com ([13.1.100.28]) by alpha.xerox.com with SMTP id <52150(1)>; Sun, 4 Apr 1999 23:09:43 PDT Received: from copper.parc.xerox.com ([13.0.211.121]) by thelma.parc.xerox.com with SMTP id <98053>; Sun, 4 Apr 1999 23:09:32 PDT From: "Larry Masinter" To: "MURATA Makoto" , Subject: RE: Starting the ietf-xml-mime mailing list Date: Sun, 4 Apr 1999 23:09:03 PDT Message-ID: <000b01be7f2a$cdef0420$79d3000d@copper.parc.xerox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-reply-to: <199904050333.AA00171@archlute.apsdc.ksp.fujixerox.co.jp> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: > 1. Problem statement > > We would like the MIME parser to be able to dispatch different sorts > of XML documents to different applications, such as specialized > programs that handle just one type of XML document. Because MIME > parsers do not look inside the MIME parts, identifiying the sort of > documents must be done in the MIME headers. However, neither text/xml > nor application/xml allow such information. > > 2. Possible solutions > > Three approaches have been proposed. They are (1) specialized media > types such as text/calendar, (2) a top-level media type xml and its > subtypes such as xml/calendar, and (3) a new parameter "externalid" of > text/xml and applcation/xml. You left out the obvious one: for some kinds of media, it is necessary for the handler of the MIME media type to actually dispatch to one of several possible media type handlers. Rather than fixing MIME, which does the job of labelling data adequately, why not fix the software? In general, you cannot solve the problem of "dispatch to the appropriate handler" by modifying MIME, since finding the appropriate handler is platform and installation dependent. Some elements of this argument were taking place in a discussion with the W3C HTML working group, which was considering registering "text/xhtml" as a way of representing the XMLified version of HTML. MIME types are also used in some instances in "content negotiation" (prospectively telling a recipient what something would be if it were to be subsequently retrieved), as well as in "content labelling". New media types and media parameters don't help much with either, unfortunately. Many current implementations of content dispatch don't allow dispatch based on media type parameters, in any case. E.g., you can't select one handler for "text/plain;charset=us-ascii" and a different one for "text/plain;charset=utf8", even though you might have a more desirable ascii-only editor and a slower or fuller Unicode-based editor installed. So adding more parameters doesn't really help for content-dispatch with current implementations. And adding more MIME types for each kind of combination of XML seems like a recipe for disaster. If we have html, xhtml, html-netscape, html-microsoft, html-optimized-for-msie-on-windows-nt50, each with slightly different definitions, would they get separate MIME types? The same arguments apply for profiles of TIFF, and probably apply to profiles of Postscript. Postscript-2-laserwriter-fonts isn't a separate MIME type from Postscript-1, even though in situations, you might have the capability of displaying one but only printing the other. Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id UAA14789 for ietf-xml-mime-bks; Sun, 4 Apr 1999 20:38:29 -0700 (PDT) Received: from smtp.gatewaymail.net (root@smtp.gatewaymail.net [207.34.179.250]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id UAA14784; Sun, 4 Apr 1999 20:38:28 -0700 (PDT) Received: from a2a00204 (a2a00204.intergate.bconnected.net [209.53.8.6]) by smtp.gatewaymail.net (8.8.7/8.8.7) with SMTP id EAA09623; Mon, 5 Apr 1999 04:37:16 -0700 Message-Id: <3.0.32.19990404203656.00c71cc0@pop.intergate.bc.ca> X-Sender: tbray@pop.intergate.bc.ca X-Mailer: Windows Eudora Pro Version 3.0 (32) Date: Sun, 04 Apr 1999 20:38:54 -0700 To: Paul Hoffman / IMC , ietf-xml-mime@imc.org From: Tim Bray Subject: Re: Starting the ietf-xml-mime mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: At 08:04 PM 4/4/99 -0700, Paul Hoffman / IMC wrote: >OK, we've got about 30 people who signed up for the list. I think the first >order of business is for someone to say what is incorrect and/or lacking in >RFC 2376. And just to save folks a couple of keyclicks, that's at http://www.cis.ohio-state.edu/htbin/rfc/rfc2376.html -Tim Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id UAA14446 for ietf-xml-mime-bks; Sun, 4 Apr 1999 20:33:27 -0700 (PDT) Received: from mx.fujixerox.co.jp (firewall-user@mx.fujixerox.co.jp [202.32.191.10]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id UAA14439 for ; Sun, 4 Apr 1999 20:33:26 -0700 (PDT) Received: by mx.fujixerox.co.jp; id MAA20657; Mon, 5 Apr 1999 12:33:54 +0900 (JST) Received: from ns1.fujixerox.co.jp(129.249.118.101) by mx.fujixerox.co.jp via smap (V3.1) id xma020502; Mon, 5 Apr 99 12:33:17 +0900 Received: from kspgwy.ksp.fujixerox.co.jp (kspmailer [129.249.213.100]) by ns1.fujixerox.co.jp (8.9.3/3.7W99033010) with ESMTP id MAA17304; Mon, 5 Apr 1999 12:31:10 +0900 (JST) Received: from sun386i.apsdc.ksp.fujixerox.co.jp (sun386i.apsdc.ksp.fujixerox.co.jp [129.249.240.113]) by kspgwy.ksp.fujixerox.co.jp (8.9.1a/3.6W) with SMTP id MAA14263; Mon, 5 Apr 1999 12:33:15 +0900 (JST) Received: from archlute.apsdc.ksp.fujixerox.co.jp (archlute.apsdc.ksp.fujixerox.co.jp [129.249.240.52]) by sun386i.apsdc.ksp.fujixerox.co.jp (8.6.9+2.4W/3.4Wbeta3) with SMTP id MAA26949; Mon, 5 Apr 1999 12:31:17 +0900 Message-Id: <199904050333.AA00171@archlute.apsdc.ksp.fujixerox.co.jp> From: MURATA Makoto Date: Mon, 05 Apr 1999 12:33:03 +0900 To: ietf-xml-mime@imc.org Subject: Re: Starting the ietf-xml-mime mailing list In-Reply-To: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> MIME-Version: 1.0 X-Mailer: AL-Mail32 Version 1.01 Content-Type: text/plain; charset=us-ascii Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: Paul Hoffman / IMC wrote: > OK, we've got about 30 people who signed up for the list. I think the first > order of business is for someone to say what is incorrect and/or lacking in > RFC 2376. Here it is. I will also post my summary of the discussion at the xml-dev mailing list very soon. Makoto ------------------------------------------------------------- Needs more information in the MIME header! (DRAFT) MURATA Makoto, Paul Hoffman, Frank Dawson, Jim Whitehead 1. Problem statement We would like the MIME parser to be able to dispatch different sorts of XML documents to different applications, such as specialized programs that handle just one type of XML document. Because MIME parsers do not look inside the MIME parts, identifiying the sort of documents must be done in the MIME headers. However, neither text/xml nor application/xml allow such information. 2. Possible solutions Three approaches have been proposed. They are (1) specialized media types such as text/calendar, (2) a top-level media type xml and its subtypes such as xml/calendar, and (3) a new parameter "externalid" of text/xml and applcation/xml. (1) Specialized mime types For each specialized applications of XML, we introduce a new subtype. It may introduce more parameters and might even have some added security consideration. This is the approach that has been assumed by the authors of RFC2376. Pros: Each application will be documented by some RFC. Cons: When the MIME parser does not know of such a subtype, the only available fallback is text/plain or application/octet-stream. That is, the MIME parser cannot invoke generic XML parsers/viewers, but has to display the document as a plain text file or save the document in a file. Each specialized application will require a new subtype registration, which takes a lot of time and therefore can have long delays. (2) New top-level media type xml and its subtypes Pros: Fallback to "xml/plain" allows the use of generic XML parsers/viewers. We can also lift the line termination rule of the top-level media type "text". Cons: It is extremely difficult to register a new top-level media type and therefore can have long delays (practically, who wants to do this?). The default behavior is probably not a good enough reason. Each specialized application will require a new subtype registration, which takes a lot of time and therefore can have long delays. (3) A new parameter "externalid" for text/xml and application/xml This parameter specifies the externalID from the DOCTYPE of the XML document (if the DOCTYPE is present). Examples would be: Content-type: text/xml; externalid="http://www.foo.com/whizzy.dtd" or Content-type: application/xml; charset="utf-16be"; externalid="-//IETF//DTD vCard v3.0//EN" Pros: This is probably the easiest solution which also provides XML-specific fallback. Requires no registration with a central authority. Other parameters can be added in the future when we have new schemata or when we find new usage patterns for DTDs. The definitions for those parameters can define which sets of parameters can appear together. Cons: DTD's do not necessarily exist. For example, RFD metadata do not have DTD's. The use of DTD's to choose applications might be an abuse of DTD's. Moreover, some DTD's might be handled by many different programs on a system, such as by a specialized processor and one or more XML browsers. On the other hand, some applications (such as XML browsers) handle a variety of DTD's. There will be new schemata that will probably overshadow DTD's, and these schemata may not use externalIDs the same way they are used in today's DTDs. (4) Yet another parameter "optinfo" or "ADD-PARAM" On top of (3), provide yet another parameter "optinfo" (list of name-value pairs) or "ADD-PARAM" (plain text) for additional information. Pros: Some applications of XML require even more appliction-specfic information so as to launch appropriate software tools. For example, if iCalendar information is captured by an XML DTD, the text/xml or application/xml MIME header has to mimick "method", "component", and "optinfo" of text/icalendar. (The latest internet draft for text/icalendar is available at: ftp://ftp.isi.edu/internet-drafts/draft-ietf-calsch-ical-12.txt) If this parameter is not available, people will abuse the parameter "externalid" by providing different names for the same DTD so as to express more information. This parameter stops such abuse. Cons: The "optinfo" parameter makes it difficult for a simple MIME parser to know what to expect in the parameter. The "ADD-PARAM" parameter does not have this problem, but does not have enough expressiveness. Note: None of the above proposals handle non-monolithic XML documents very well, since different islands of non-monolithic XML documents belong to different namespaces and thus different schemata. For example, the MIME parser cannot invoke vCard applications if the vCard is embeded by the namespace mechanism. Makoto Fuji Xerox Information Systems Tel: +81-44-812-7230 Fax: +81-44-812-7231 E-mail: murata@apsdc.ksp.fujixerox.co.jp Received: (from majordomo@localhost) by mail.proper.com (8.8.8/8.8.5) id UAA11753 for ietf-xml-mime-bks; Sun, 4 Apr 1999 20:04:05 -0700 (PDT) Received: from aum (ip11.proper.com [165.227.249.11]) by mail.proper.com (8.8.8/8.8.5) with ESMTP id UAA11746 for ; Sun, 4 Apr 1999 20:04:04 -0700 (PDT) Message-Id: <4.2.0.32.19990404200153.00c6a820@mail.imc.org> X-Sender: phoffman@mail.imc.org X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.32 (Beta) Date: Sun, 04 Apr 1999 20:04:32 -0700 To: ietf-xml-mime@imc.org From: Paul Hoffman / IMC Subject: Starting the ietf-xml-mime mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-ietf-xml-mime@imc.org Precedence: bulk List-Archive: List-Unsubscribe: OK, we've got about 30 people who signed up for the list. I think the first order of business is for someone to say what is incorrect and/or lacking in RFC 2376. --Paul Hoffman, Director --Internet Mail Consortium