Subject: Re: Proposal: WebDAV and transaction

From: "B. Shadgar" <[email-masked]>
Date: Wed, 11 Sep 2002 18:26:50 +0100

"Roy T. Fielding" wrote:

> I'll try to explain.  It is fundamental to HTTP that intermediaries
> are able to inspect the method of an HTTP request in order to
determine
> the semantics of a request, and thereby its associated access control
> and/or authentication requirements.  What you are suggesting is that
> we bypass that feature in HTTP via a new syntax that tunnels arbitrary

> methods within XML via HTTP, effectively bypassing all of the benefits

> of using HTTP in the first place.
>
> Sound familiar? It should, since this is the same objection that I
have
> frequently given to the use of SOAP for tunneling arbitrary semantics
> though an HTTP POST method.
>
> Transactions can be accomplished by using a request to ask the server
> for a transaction context, possibly multi-level, and then sending
> the sequence of requests with a calculated transaction-request-id
> in the header fields, to each the server responds with 202 Accepted
> or an error, and finalized with a commit or abort method, to which
> the server responds with the appropriate message for the entire
> commit.  Such a transaction mechanism accomplishes the same thing
> without violating the requirements of HTTP.

Thanks for your explanation. You have open a new view to me. But I
am thinking is this way stateless or not?

Regards,

Bita

---

From: "Roy T. Fielding" <[email-masked]>
Date: Thu, 12 Sep 2002 15:34:29 +0200

> am thinking is this way stateless or not?

As stateless as possible given that we are talking about transactions.
Each request contains all of the information necessary to understand
that request, which is the only issue left given that a transaction
implies that the requests are stored for committal rather than applied
immediately.  In other words, it is just as stateless as one method
containing lots of requests.

....Roy