OASIS ebXML Messaging Services TC

Re: [ebxml-msg] Issue 56: Specification / Schema conflict resolution

  • 1.  Re: [ebxml-msg] Issue 56: Specification / Schema conflict resolution

    Posted 02-17-2002 02:35
    Dick,
    
    Sorry to return to an issue after it's a little cold.
    
    I agree completely where the document and specification overlap they should
    agree.  However, the schema contains information not in the document and
    visa versa.  In addition, we're not going to be perfect.   Our comments on
    the Description element and the SequenceNumber datatype shouldn't be taken
    to mean we've found every place the two things don't match.
    
    I don't agree the document should win simply because we discussed it more in
    our group.  As a group, we should be publishing a schema and a document
    which form a unified answer to the question of "how do I send an ebXML
    document?"  We must ratify both.  We must also understand how the schema
    will be used and recognise that use in our document.
    
    While some XML parsers may cache copies of the schema, what we publish at
    the location described in the document is a normative part of our overall
    protocol description.  The interesting thing is how a receiving application
    could possibly override the behaviour of the XML parser to meet the terms of
    the document.  Since the SOAP processor and it's embedded XML parser (in a
    layered approach using a generic SOAP processor) or an XML parser alone
    (feeding information to a somehow mixed MSH and SOAP processor) will process
    the document before the code of an ebXML Messaging handler, the message
    should be validated against the schema before the MSH starts doing its work.
    Certainly, code could be written to send a message that won't validate
    against the schema but the receiver will have a hard time using code to get
    past the validation error.
    
    I generally see the document as describing (referencing and explaining) the
    normative information in the schema for the areas the two things overlap.
    The layers in an MSH implementation sitting on top of an XML parser (and,
    likely, a SOAP processor) are what developers can directly control.  They
    have to take the schema as a given.  That's why it "wins" if there should
    ever be a conflict now or in the future.
    
    thanx,
        doug