Proposed note on recommending extensions

Per my action item (2004-11-10: DBooth will produce text for the spec
re: slide 12 of his presentation. ),
here is proposed text to add as a Note to Part 1 sec 6.1.1 after the
paragraph beginning "If a WSDL document declares an extension . . . .".

A key purpose of an extension is to formally indicate (i.e., in a
machine-processable way) that a particular feature or convention is
supported or required.  This enables toolkits that understand the
extension to engage it automatically, while toolkits that do not yet
understand a required extension may be able to flag it to an operator
for manual support.

If a Web service requires the client to follow a particular convention
that is likely to be automatable in WSDL toolkits, then that convention
SHOULD be indicated in the WSDL document as a wsdl:required extension,
rather than just being conveyed out of band, even if that convention is
not currently implemented in WSDL toolkits.  

This practice will help prevent interoperability problems that could
arise if one toolkit requires a particular convention that is not
indicated in the WSDL document, while another toolkit does not realize
that that convention is required.  It will also help facilitate future
automatic processing by WSDL toolkits.  


David Booth
W3C Fellow / Hewlett-Packard

Received on Thursday, 16 December 2004 15:27:27 UTC