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Re: Implications of XML 1.1 for WSDL 2.0

From: Jean-Jacques Moreau <jean-jacques.moreau@crf.canon.fr>
Date: Fri, 14 May 2004 15:28:00 +0200
Message-ID: <40A4C960.5000708@crf.canon.fr>
To: Mark Nottingham <mark.nottingham@bea.com>
Cc: Arthur Ryman <ryman@ca.ibm.com>, www-ws-desc@w3.org

Mark, I've pointed this out earlier; see [1].
Arthur, there's also the issue that XML Schema is (today) XML 1.0 only; 
also see [1].

JJ.

[1] <http://lists.w3.org/Archives/Public/www-ws-desc/2004May/0011.html>

Mark Nottingham wrote:

>
> Note that the XMLP WG is just finalising its decision for this issue 
> as it impacts SOAP 1.2; it would be good if the approaches were 
> co-ordinated (apologies if this was already well-known).
>
>
> On May 12, 2004, at 10:41 AM, Arthur Ryman wrote:
>
>>
>> This note completes my action item of 2004-04-29.
>>
>> The WSDL 2.0 spec is written in terms of the XML Infoset. The Infoset 
>> spec was recently revised [1] to cover XML 1.1. There are at least 
>> two changes in XML 1.1 that affect the Infoset:
>>
>> 1. The set of legal values for character data has increased. However, 
>> on closer reading of the Infoset spec, it defines a character code as 
>> any number in the ISO 10646 range of 0 to #x10FFFF, even though not 
>> all of these are legal XML codes. So in this case there is no problem 
>> since the Infoset spec is general enough to describe even documents 
>> that are not well-formed XML 1.1, i.e. that contain illegal character 
>> codes.
>>
>> 2. The set of legal values for characters that may appear in element 
>> names, attributes names, enumerated attribute values, targets of 
>> processing instructions, etc., has increased. The Infoset spec 
>> doesn't define these, instead saying that it takes whatever an XML 
>> parser hands it.
>>
>> There are also changes to Namespaces that are reflected in the new 
>> Infoset spec.
>>
>> My conclusion is that the Infoset spec is loose in the sense that it 
>> doesn't nail down every aspect of an Infoset. That is fine for the 
>> Infoset spec, but I do NOT think it is fine for WSDL 2.0, since in 
>> practice systems will be interchanging concrete documents using XML 
>> 1.0 or XML 1.1. If we are not clear on this, then we will probably 
>> hit interoperability problems when XML 1.1 gets adopted.
>>
>> I think there are two extreme approaches and probably some 
>> intermediate cases.
>>
>> Case 1. We state that WSDL 2.0 MUST use  XML 1.0 only. This means 
>> WSDL 2.0 documents MUST use XML 1.0 and that any imported or included 
>> document MUST also use XML 1.0.
>>
>> Case 2. We state that WSDL 2.0 MAY use either XML 1.0 or XML 1.1 and 
>> that conformant processors MUST support both, and any combination of 
>> versions for all imported or included documents.
>>
>> Case 1 has the advantage of simplicity and ease of implementation. 
>> However, it denies the benefits of XML 1.1 which may be significant 
>> to some users. For example, ease of authoring on IBM-compatible 
>> mainframes (NEL), and the flexibility to use more international 
>> characters in names.
>>
>> Case 2 has the disadvantage that it is harder to implement since 
>> there are not a lot of XML 1.1 parsers in production yet. It has the 
>> benefit of making the features of XML 1.1 available.
>>
>> I suspect that even if we adopt Case 2 that WS-I will issue a Profile 
>> that specifies Case 1.
>>
>> [1]  http://www.w3.org/TR/xml-infoset/
>>
>>  Arthur Ryman,
>>  Rational Desktop Tools Development
>>
>>  phone: +1-905-413-3077, TL 969-3077
>>  assistant: +1-905-413-2411, TL 969-2411
>>  fax: +1-905-413-4920, TL 969-4920
>>  mobile: +1-416-939-5063
>>  intranet: http://w3.torolab.ibm.com/DRY6/
>
>
> -- 
> Mark Nottingham   Principal Technologist
> Office of the CTO   BEA Systems
>
Received on Friday, 14 May 2004 09:29:14 GMT

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