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RE: change the question slightly maybe...schemas, leveraging their object orientedness??

From: Dare Obasanjo <dareo@microsoft.com>
Date: Sat, 18 Oct 2003 12:20:56 -0700
Message-ID: <830178CE7378FC40BC6F1DDADCFDD1D1D51656@RED-MSG-31.redmond.corp.microsoft.com>
To: "Dean Hiller" <dhiller@avaya.com>, "Dean Hiller" <dhiller@avaya.com>
Cc: <xmlschema-dev@w3.org>

It depends. Does the program perform schema validation? If it does then it'll error since the type  xsd2:MyExtendedAddress cannot be located. On the other hand if it doesn;'t then you are fine but then again you don't need a schema to actually get this behavior. 


From: xmlschema-dev-request@w3.org on behalf of Dean Hiller
Sent: Sat 10/18/2003 12:14 PM
To: Dean Hiller
Cc: xmlschema-dev@w3.org
Subject: change the question slightly maybe...schemas, leveraging their object orientedness??

This is a yes or no question.  Just a little long on the xml explaining....

XSD 1....
<complexType name="Address">
    <sequence><element name="name" type="string"/></sequence>

<element name="PurchaseOrder">
    <complexType><sequence><element name="shipTo"

XSD 2...
<complexType name="MyExtendedAddress">
      <extension base="XSD1:Address">
             <element name="state" type="string"/>

   <shipTo xsi:type="xsd2:MyExtendedAddress">

A program that only has the old XSD1 should only get notified of the
name, not the state when XML 1 comes in.  Is that correct???  YES or NO


Dean Hiller wrote:

> Anybody? please??
> thanks,
> dean
> Dean Hiller wrote:
>> If I have some xml implementating schema A.xsd
>> <superclass>
>>    <someElement/>
>> </superclass>
>> And then I write B.xsd which extends A.xsd and the xml looks
>> something like this
>> <subclass xmnls="......A.xsd">
>>     <someElement/>
>>     <anAddedElement/>
>> </subclass>
>> BUT, I must be missing something.  There is now a program A which
>> only knows about A.xsd.  It should be able to receive the xml that
>> adheres to B.xsd and just skip the unknown elements and only deal
>> with the known ones(ie someElement).  The problem is there seems to
>> be nothing to tell the parser that subclass extends superclass unless
>> you know of B.xsd.
>> I thought the idea of extensions was object-orientedness.  The
>> subclass should be able to be read by program A as the superclass. 
>> (ie. program A knows about a car, and we created a Ford car, so
>> program A can still see it as a car).  I am afraid that a parser will
>> puke at this since it does not adhere to A.xsd.  There must be
>> something else in the xml I am missing?????
>> Also, how would I write the xsd and xml for this?  I wish the
>> tutorial explained more in this area.  I would say this is by far the
>> most important part of xsd's.  Extension without breaking previous
>> programs. Previous programs just ignore additional data.
>> thanks,
>> dean
Received on Saturday, 18 October 2003 15:24:03 UTC

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