Subject: Re: XML DTD update proposition

From: [email-masked]
Date: Mon, 3 Jan 2000 09:46:39 -0500

Philippe:
You point out an interesting design point. That is, is the iCalendar XML 
DTD intended to be an XML object for calendars or an alternate XML 
representation for the standard iCalendar format?
We don't need two standard calendar formats, if at all possible. This 
effort is definitely not an attempt to define a new calendar format. It is 
not an effort to define a new calendar XML application, based on 
iCalendar. I think you would agree.
There is but one standard IETF calendar format. That is iCalendar, defined 
by RFC2445. Hence, this format is an alternative XML representation for 
iCalendar. As such, an implementation will already understand iCalendar 
data types. The recurrence grammar is one of these dozen or so standard 
iCalendar data types. It is called RECUR. 
So, any valid iCalendar implementation (including one that understands a 
new alternative XML representation) will already have support for the 
standard iCalendar data types. There is no need to make interpretation of 
a XML representation of an iCalendar object any harder or more complex for 
an iCalendar implementation.
No, it is not a good idea to create RRULE and EXRULE properties as emply 
element types with the RECUR data type redefined as attributes.
-- Frank

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From: Philippe Lesage <[email-masked]>
Date: Tue, 4 Jan 2000 17:21:49 -0800

> standard iCalendar data types. 

Ok, but it is not a valid reason for preventing the DTD from describing the
data types internal structure.

You imply that the DTD could just have one single element :
<!ELEMENT iCalendar (#PCDATA) > 
Any valid ICal implementation should be able to understand this string....

>There is no need to make interpretation of 

I don't think so. In fact, all this work is done by your favorite xml parser.

> element types with the RECUR data type redefined as attributes.

Best Regards

Philippe.

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From: Doug Royer <[email-masked]>
Date: Sun, 09 Jan 2000 23:35:01 -0800

> data types internal structure.

So what is the point? It seems to me that you are saying you really don't
want to work on iCalendar and add what you think is needed. You just 
want to work with XML? iCalendar is this groups work.

> I don't think so. In fact, all this work is done by your favorite xml parser.

Except when you wish to exchange the data with an iCalendar tool. What
do you do with the extra data?

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From: Philippe Lesage <[email-masked]>
Date: Mon, 10 Jan 2000 01:02:10 -0800

>want to work with XML? iCalendar is this groups work.

As Paul & Michael explained it better than me, other non iCalendar application
might need to exchange data with a XML compliant calendaring server. So
it is really a problem for them if they can't see the RECUR datatype internal
structure for example. The XML representation is for me usefull is only one
case : exchange with non ICal application.

I think it is really an opportunity for this group to define a good Ical
xml format which can be used by any xml aware application. It is just too bad
that each one defines it's one DTD or schema. In this case, everyone lose.