Paul
responded to yesterday's post to explain the need for the new
W3C XML Schema Patterns for Databinding Working Group, which he chairs. He points out that the move by the WS-I to deprecate encoding in favor of literal schema was based on a reasonable argument (that there is no spec for how to translate an XSD in a WSDL - which describes a tree of named structural types - into an input to SOAP encoding - which acts on a graph of unnamed structural types) but that the end result made interop harder because it opened up the door to using all of XSD. I disagree. The WSDL spec opened the door to using all of XSD for both encoded and literal bindings. The work that SOAPbuilders did provided a set of test cases for mapping common types and structures. It did not, however, address questions like “how do you map substitution groups to code using an encoded binding”,
something that is completely legal according to WSDL. In other words, the shift from encoding to literal in no way widened the number of databinding cases we had to be concerned about. That's a red herring. The real problem has been the lack of SOAPbuilders-style test suites to cover more of XSD or the lack of a formal specification that narrows XSD to a more easily supported subset (an option that the WS-I discarded).
Posted
Dec 09 2005, 09:07 AM
by
tim-ewald