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Re: [SOAP Encoding Issue] Multi-reference 'id' attribute - NOT a real ID

From: Asir S Vedamuthu <asirv@webmethods.com>
Date: Wed, 17 Oct 2001 09:21:47 -0400
Message-ID: <004a01c1570e$ac4869b0$883c010a@webmethods.com>
To: "Williams, Stuart" <skw@hplb.hpl.hp.com>, <xml-dist-app@w3.org>
Stuart,

XML Schema type ID is not the same as XML 1.0 type ID. The following
functions do not operate on XML Schema type ID (I am not saying they have
to),

(a) id ("array-1")
(b) xpointer(id("array-1")) - [2]

[1] http://www.w3.org/TR/xpath#function-id
[2] http://www.w3.org/TR/xptr/#bare-names

Regards,

Asir
----- Original Message -----
From: "Williams, Stuart" <skw@hplb.hpl.hp.com>
To: "'Asir S Vedamuthu'" <asirv@webmethods.com>; <xml-dist-app@w3.org>
Sent: Tuesday, October 16, 2001 5:21 AM
Subject: RE: [SOAP Encoding Issue] Multi-reference 'id' attribute - NOT a
real ID


Asir,

How does this square with:

"SOAP uses unqualified attribute information items with a local name of id
and a type of ID in the http://www.w3.org/2001/XMLSchema namespace to
specify the unique identifier of an encoded element. "

Also from Part 2 Section 2, 'Relation to XML'

Thanks,

Stuart

> -----Original Message-----
> From: Asir S Vedamuthu [mailto:asirv@webmethods.com]
> Sent: 15 October 2001 21:34
> To: xml-dist-app@w3.org
> Subject: [SOAP Encoding Issue] Multi-reference 'id' attribute - NOT a
> real ID
>
>
> Issue
>
> Unqualified attribute named 'id' and of type 'ID' per the XML 1.0
> specification DOES NOT MEAN that it is of type ID !!
>
> Part 2, Section 4.1 'Rules for Encoding Types in XML' [1],
> rule 5 says that
> a multi-reference value is encoded as an independent element
> containing a
> local, unqualified attribute named 'id' and of type 'ID' per
> the XML 1.0
> specification.
>
> Part 2, Section 2 'Relation to XML' [2] says that a SOAP
> message MUST NOT
> contain a Document Type Declaration (DTD).
>
> [From Processing Model Workshop] In general, XML processes
> can be classified
> into two categories: bootstrap and application processes. XML
> Information
> Set is the basic unit of processing. Bootstrap process comes first.
> Bootstrap process applies processing rules from XML 1.0, XML
> Namespaces and
> XML Base. XML Information Set is available after bootstrapping.
>
> During the bootstrap processing, if there is a DTD, the
> bootstrap process
> will consume it. It is the DTD that tells the bootstrap
> process that 'id'
> attribute is of type XML 1.0 ID. A SOAP message cannot
> contain a DTD and ID
> processing never happens.
>
> A schema document MAY be used to describe the payload. This schema may
> describe that an unqualified attribute named 'id' is of type
> 'ID'. But,
> schema does not play a role in the bootstrap process. And,
> SOAP does not
> mandate using a schema aware processor,
> post-schema-validation-infoset and
> [ID / IDREF table] [3]
>
> Lets say a SOAP decoder uses DOM Level 2 Core API to traverse a SOAP
> message. Decoder will use the [4] Document.getElementById(in DOMString
> elementId); DOM specifies one constraint on this method - "The DOM
> implementation must have information that says which
> attributes are of type
> ID. Attributes with the name "ID" are not of type ID unless
> so defined.
> Implementations that do not know whether attributes are of
> type ID or not
> are expected to return null"
>
> The conclusion here is that multi-reference representation's
> 'id' attribute
> is not a real XML 1.0 ID. This means,
>
> (a) Implementations must use additional code to simulate XML 1.0 ID
> (b) It fails to satisfy Usage Scenario S21 [5]. 'Cos,
> implementations must
> parse the entire document to construct an id and bearing
> element information
> item table.
>
> [1] http://www.w3.org/TR/2001/WD-soap12-part2-20011002/#encrules
> [2] http://www.w3.org/TR/2001/WD-soap12-part2-20011002/#reltoxml
> [3] http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#sic-id
> [4] http://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-getElBId
> [5] http://www.w3.org/TR/2001/WD-xmlp-reqs-20010319/#S21
>
> Regards,
>
> Asir S Vedamuthu
>
> webMethods, Inc.
> 703-460-2513 or asirv@webmethods.com
> http://www.webmethods.com/
>
Received on Wednesday, 17 October 2001 09:18:05 GMT

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