Marc Hadley's Blog

WADL Revision

I got some useful feedback following the publication of the original version of the Web Application Description Language (WADL) and have revised the specification accordingly. Thanks particularly to Mark Nottingham and Philippe Le Hegaret for their useful comments, many of which are addressed in the latest version of the WADL specification (PDF) and WADL schema

Changes since the previous version:

• Resources may now be nested. This allows the resources to be specified in a tree that closely parallels typical URI structures
• I've added global operation groups as a lexical shortcut to specifying the same set of operations for multiple resources. This isn't quite a resource typing capability as requested by Mark but provides much the same functionality (IMO)
• URIs are now used to refer to WADL components instead of XML QNames
• Clarified escaping requirements for URIs with embedded parameters
• Assorted other clarifications and additional explanatory text

Still to do:

• Specify the extensibility model including scope and inheritance
• Investigate registering a media type for WADL documents

The W3C has just created a mailing list for discussion of Web description, if you have comments or thoughts about WADL or similarly targetted description languages then why not join the list and share your ideas.

Comments

• Hi Marc,

  I'm obviously late in jumping on this WADL train (just learned of its existence through the "RestFul Webservices" book (by Richardson and Ruby)

  Anyway, the clear parallelism between WADL and WSDL made me wonder if there has been (to your knowledge) any effort to work towards a UDDI like equivalent as well: some way of organizing service registry and discovery.

  I'm still new to WADL (have to complete reading the spec) but this could be as straightfoward as some kind of Google search specialized in WADL files. (Which should be a service having it's own WADL description of course)

  Possibly together with some convention (naively thinking along the lines of /robots.txt) for letting web hosts publish their service descriptions...

  Posted by: mpo on July 10, 2007 at 11:34 PM

• Hi Marc,

  Also a little late to WADL, but after writing an article on the subject, I got some feedback from Leigh L. Klotz over on the W3C XForms mailing list, who noticed some relation to WADL and XForms.
  I also think there might be some working relation, here is the thread on WADL and XForms : http://lists.w3.org/Archives/Public/www-forms/2007Jul/0029.html
  Would appreciate your thoughts and feedback on the thread.
  
  
  

  Posted by: drubio on July 25, 2007 at 11:17 PM

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