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- To: "Simon St.Laurent" <email@example.com>,<firstname.lastname@example.org>
- Subject: RE: [xml-dev] headers (was ERH on Web Services
- From: "Don Box" <email@example.com>
- Date: Sun, 9 Feb 2003 12:09:00 -0800
- Thread-index: AcLQbYrvWSPcKBVbQG6n9FqylgxISgAB7irU
- Thread-topic: [xml-dev] headers (was ERH on Web Services
The inability for an XML entity to "contain" another XML entity (along with a text declaration, doctype decl, etc) has less to do with SOAP than it has to do with XML core. There are several ways to do it (independent from SOAP), but few people are thrilled with the results. Relating this to SOAP's prohitibion on DTDs is a red herring IMO.
As for yet another layer to add headers, the world should be used to it by now. HTTP introduced its own header mechanism despite the fact that TCP supported header extensions back in the 1980's. By now, people should be used to seeing protocols that attempt to avoid unneccessary dependencies on adjacent layers.
From: Simon St.Laurent [mailto:firstname.lastname@example.org]
Sent: Sun 2/9/2003 11:01 AM
Subject: RE: [xml-dev] headers (was ERH on Web Services
email@example.com (Don Box) writes:
>Most of the SOAP spec is dedicated to the processing model of the
>"mashed header/body" of a SOAP envelope. Check out part 1 of the
>current SOAP/1.2 spec for more details.
I'm aware of what SOAP does. I just think it's a bad idea.
>FWIW, SOAP headers were introduced back in the 1990's to allow for
>orthogonal extensibility over app-specific payloads. As for SOAP vs.
>MIME vs. HTTP headers, SOAP tries to generalize the concept of an
>intermediary to allow more flexibility in forming a message path. I
>believe this is a non-goal for MIME and rather is left for HTTP, SMTP,
>etc. to invent for themselves.
I think SOAP has made a gigantic mistake in this regard, and its
insistence on an envelope has created new problems for XML like the
recurring need to subset XML that pops up on TAG. ("You can't stuff a
whole XML document with DOCTYPE into this 'envelope' we created, so
let's chop up the contents into bits we can digest.")
Developing a protocol that used XML for headers might well have made
sense. Developing a protocol that slaps headers and content into a
single XML document as children of an envelope is very different.
It's especially unfortunate given that HTTP already had a history of
using (MIME-based) headers for message path management, and SOAP still
most frequently rides inside of that.
Not like I can stop it of course, but marveling at SOAP's ghastliness is
an entertaining sport, one that seems unlikely to disappear.
Ring around the content, a pocket full of brackets
Errors, errors, all fall down!
http://simonstl.com -- http://monasticxml.org
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