Chris Malley wrote: > > See the SOAP 1.2 spec at http://www.w3.org/TR/2001/WD-soap12-20010709. > As stated towards the end of Section 5.1: > > "9. A NULL value or a default value MAY be represented by omission > of the accessor element. A NULL value MAY also be indicated by > an accessor element containing the attribute xsi:null with value > '1' or possibly other application-dependent attributes and values." > > So the treatment of 'null' is left up to the implementation, > since "MAY" indicates that these are only suggestions. > I believe that Apache SOAP 2.2 takes the 'xsi:null' approach.
You are correct. One ramification of this is that there is no way using the RPCProvider to get Apache SOAP 2.2 to omit the return element. This may cause interoperability problems with other web services which do not expect to see a response. The RPCProvider in Apache xml-axis distinguishes between methods who are declared to return void, and methods who happen to return null in this one instance. If anyone listening is interested in interoperability issues, you might want to take a look at http://www.apache.org/~rubys/ApacheClientInterop.html and some of the web pages which it is linked to. It has been an interesting journey. I have found that sending only valid SOAP messages is not sufficient. Nor is being able to consume every message that you can produce. The harder problem is being able to produce messages to a required specification, and to consume every possible response. It appears that this journey is one that will take a while - exploring all of the edge cases and finding new nooks and cranies. - Sam Ruby
