[NEW ISSUE] WS-MEX - add the ability for a client to specify the format of the returned data

Right now the GetMetadata operation leaves it up to the service to decide 
which of the three possible forms (EPR, URI or the data itself) is 
returned for each Dialect requested.  This is problematic because there 
may be times when the client needs a particular format to complete its 
work.  For example, if the client wants to update the metadata (using 
Transfer.Put) then it needs an EPR to the Metadata Resource.  But there is 
no way for the client to demand that the GetMetadata operation return an 
EPR at all.

Proposal:
Add a new optional element to the GetMetadata request that specifies the 
formats requested:

  <mex:GetMetadata ?>
    (<mex:Dialect>xs:anyURI</mex:Dialect>
      (<mex:Identifier>xs:anyURI</mex:Identifier>)?
      (<mex:Format>xs:anyURI</mex:Format>)*
    )?
  </mex:GetMetadata>

When not present the default is as current defined - up to the service to 
decide which (and how many) to return. We then need to define 3 URIs for 
each of the formats - eg:
        http://.../mex/format/EPR
        http://.../mex/format/URI
        http://.../mex/format/metadata
for completeness, we could also define the default one too:
        http://.../mex/format/any

If the service is unable to return the requested format then it skips that 
requested format (ie. nothing is returned for that one dialect/format).

thanks
-Doug
______________________________________________________
STSM  |  Web Services Architect  |  IBM Software Group
(919) 254-6905  |  IBM T/L 444-6905  |  dug@us.ibm.com