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Parts 1 and 2 Treat Defaults Inconsistently with Eachother

From: Arthur Ryman <ryman@ca.ibm.com>
Date: Fri, 19 May 2006 17:23:08 -0400
To: www-ws-desc@w3.org
Message-ID: <OF4ABF2B49.5AE68699-ON85257173.0071BA45-85257173.00757D4E@ca.ibm.com>
In Part 1 the <interface> element has a styleDefault attribute but there 
is no corresponding property in the component model. The styleDefault 
attribute is only used to determine the {style} property on the Interface 
Operation component via the XML mapping rules

However, in Part 2 there are four default attributes and they do get 
mapped to component model properties:
{soap mep default}
{http transfer coding default}
{http method default}
{http query parameter separator default}

These default properties are matched up with corresponding non-default 
properties on the component model:
{soap mep}
{http transfer coding}
{http method}
{http query parameter separator}

The "actual" values of the property in the message are defined by the 
binding rules, not the XML mapping. I find this confusing. It also has the 
disadvantage that it removes the rules from the component model  so the 
component model builder can't evaluate them. It just copies the XML 
attributes into the component model. Instead a message builder has to have 
this logic.

The Part 1 approach makes the component model simpler since the "actual" 
value of the property is computed and stored in the component model.

However, the Part 2 approach is also good because it makes WSDL generation 
simpler. For example, suppose you have the same style on several 
operations. It would be simpler to specify the default in the component 
model and serialize the WSDL with the style ommitted on the operations 
that matched the default.

I propose that we improve the spec by using the best aspects of Part 1 and 
2, and make them consistent. This requires the following changes:

1.In Part 1, add a {style default} property to the Interface component.
2. In Part 2, specify the rules for the properties in the XML mapping 
instead of the message binding, e.g. {http method} is determined by the 
actual value of the attribute if present, or the {http method default} if 
present, or is GET if the operation is safe, and it POST otherwise. This 
way, e.g. {http method} is the actual value used in the message.

Arthur Ryman,
IBM Software Group, Rational Division

blog: http://ryman.eclipsedevelopersjournal.com/
phone: +1-905-413-3077, TL 969-3077
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Received on Friday, 19 May 2006 21:23:20 GMT

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