> 4 If there is an attribute information item among the element information
item's [attributes] whose
> [namespace name] is identical to
http://www.w3.org/2001/XMLSchema-instance and whose [local name] is type,
> then all of the following must be true:
>
> My namespace "is not" http://www.w3.org/2001/XMLSchema-instance,
therefore 4.2 "does not apply"

Note that the "whose" refers to the attribute ("xsi:type"), not its value.
When there is an "xsi:type", a schema processor has to, required by the
schema spec, resolve its value to a type definition. There is nothing
Xerces (or any other schema processors) can do here.

In the scenario you described, it seems to me that you shouldn't have used
xsi:type in the first place, for the above reason.

Have you considered my suggestion about using <redefine> at all?

Sandy Gao
Software Developer, IBM Canada
(1-905) 413-3255
[EMAIL PROTECTED]



                                                                       
                      Dean Hiller                                      
                      <[EMAIL PROTECTED]        To:       [EMAIL PROTECTED]
                      m>                       cc:                     
                                               Subject:  Re: dynamic 
validation, is this a bug
                      11/20/2003 02:18                                 
                      PM                                               
                      Please respond to                                
                      xerces-j-user                                    
                                                                       
                                                                       



thanks much sandy, but I am not exactly clear on that part of the spec.  To
make sure we are looking at the same part of the spec.  Here is what I read
and my interpertation below....

4 If there is an attribute information item among the element information
item's [attributes] whose [namespace name] is identical to
http://www.w3.org/2001/XMLSchema-instance and whose [local name] is type,
then all of the following must be true:
4.1 The �normalized value� of that attribute information item must be
�valid� with respect to the built-in QName simple type, as defined by
String Valid (�3.14.4);
4.2 The �local name� and �namespace name� (as defined in QName
Interpretation (�3.15.3)), of the �actual value� of that attribute
information item must resolve to a type definition, as defined in QName
resolution (Instance) (�3.15.4) -- [Definition:]  call this type definition
the local type definition;

Notice #4....the namespace is identical to
http://www.w3.org/2001/XMLSchema-instance and the end saying "all of the
following must be true" referring to 4.1, 4.2...etc.

My namespace "is not" http://www.w3.org/2001/XMLSchema-instance, therefore
4.2 "does not apply"

I actually had this conversation with someone who was on the schema
standards body and I got the impression that this was possible.  Am I
mistaken?  I could not find anywhere in the spec that states a
contradictory statement, neither have I found a supporting one yet.
thanks,
dean


Sandy Gao wrote:




            ie.  if it only knew about a
            car, it would process the car and ignore the Ford specific
            data, or
            Honda specific data depending on what type of car it actually
            received.


      But if your Honda car claims that "I'm a Honda, and you have to treat
      me as
      a Honda" (via xsi:type), then the schema processor has no choice but
      to
      tell you I'm sorry.

      The schema spec is very clear on this. When there is an xsi:type in
      the
      instance document, its value "must resolve to a type definition",
      which
      indicates that if such resolution fails, there is an error.

      You might want to consider <redefine>ing the "standard" schema,
      instead of
      extending it. This way, you don't need to specify "xsi:type" in your
      instance. And you can switch between the "standard" and the
      "redefined"
      schemas using an entity resolver (or grammar pool in Xerces).

      Hope this helps,
      Sandy Gao
      Software Developer, IBM Canada
      (1-905) 413-3255
      [EMAIL PROTECTED]




                            Dean Hiller

                            <[EMAIL PROTECTED]        To:
      [EMAIL PROTECTED]

                            m>                       cc:

                                                     Subject:  Re: dynamic
      validation, is this a bug
                            11/20/2003 10:06

                            AM

                            Please respond to

                            xerces-j-user






          yeah, can't really do that seeing as how the protocol is a
      standard(ie. The whole xsd down below is the standard and we want to
      extend it and add a proprietary feature the protocol doesn't have due
      to
      customer requests), and you know how slow standards change.  I really
      need to accomplish it by extension.  Should I ask the xerces
      developers
      then????
          I personally don't like the any element and much prefer the
      object
      oriented-ness of schemas where you can extend other base types and
      add
      data to them though I haven't gotten them to work yet.  ideally, an
      application would just ignore extra data.  ie.  if it only knew about
      a
      car, it would process the car and ignore the Ford specific data, or
      Honda specific data depending on what type of car it actually
      received.
      thanks,
      dean

      Mike Rawlins wrote:


            At 05:27 PM 11/19/2003 -0700, Dean Hiller wrote:


                  good question.  did a quick grep...processContents is not
                  found in
                  the entire schema(schema is 300 pages).
                  Root element looks like so

                  <xsd:element name="Root" type="RootType/>
                  <xsd:complexType name="RootType">
                       <xsd:sequence>
                           <xsd:element name="Element" type="ElementType"/>
                       </xsd:sequence>
                  </xsd:complexType>

                  <xsd:complexType name="ElementType">
                    <xsd:sequence>
                        <xsd:element name="data1" type="xsd:string"/>
                    </xsd:sequence>
                  </xsd:complexType>


            Hmm, not quite what I was expecting.  If you want to play
            around with
            another approach, you might instead do something like:

            <xsd:complexType name="ElementType">
              <xsd:sequence>
                <xsd:element name="data1" type="xsd:string"/>
                <xsd:any namespace="##any" processContents="skip">
              </xsd:sequence>
            </xsd:complexType>

            Then, in your instance document try:

            <Element>
              <data1>some data</:data1>
              <ava:data2>more data</ava:data2>
            </Element>

            I'm not sure I've got the syntax exactly correct, but this may
            be
            closer to what you want and at least get you started.   This is
            approach, of course, just deals with the instance document and
            schema.   I've had a few problems with a similar approach with
            Xerces,
            but didn't have time to track them down to closure.  However,
            this or
            something similar *should* work.

            Mike

            ---------------------------------------------------------------
            Michael C. Rawlins, Rawlins EC Consulting
            www.rawlinsecconsulting.com
            Using XML with Legacy Business Applications (Addison-Wesley,
            2003)
            www.awprofessional.com/titles/0321154940


            
---------------------------------------------------------------------

            To unsubscribe, e-mail:
            [EMAIL PROTECTED]
            For additional commands, e-mail:
            [EMAIL PROTECTED]





      ---------------------------------------------------------------------
      To unsubscribe, e-mail: [EMAIL PROTECTED]
      For additional commands, e-mail: [EMAIL PROTECTED]





      ---------------------------------------------------------------------
      To unsubscribe, e-mail: [EMAIL PROTECTED]
      For additional commands, e-mail: [EMAIL PROTECTED]






---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to