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repeating element names in single XML vocabulary

• To: xml-dev@l...
• Subject: repeating element names in single XML vocabulary
• From: Lyndon J B Nixon <nixon@f...>
• Date: Wed, 27 Feb 2002 12:55:03 +0100

hi all,

although it seems intuitively wrong to use the same name for two different 
elements in the same XML vocabulary, I have been struggling with finding 
convincing arguments for avoiding this practice. Take this example:

<MyXML>
         <Part1>
                 .....
         </Part1>
         <Part2>
                 <PartsInventory>
                         <Part1>....</Part1>
                         <Part2>....</Part2>
                 </PartsInventory>
         </Part2>
</MyXML>

In the schema it is possible to differentiate the elements so that a parser 
can apply the correct schema definition for both (see code below).
As can as I can ascertain, one can still make use of all the various XML 
standards (DOM, XSLT, XPath, ..) provided
(1)  the parser is instructed to begin parsing within the first Part2 
element (and hence unambiguously deals with the Part1 and Part2
elements it encounters)
(2)  operations on a Part1 or Part2 element is qualified (e.g. only Part1 
elements which are children of PartsInventory, all Part2 elements
  which are not children of MyXML)

So, is the worst result of repeating element names that someone writing 
code to operate with this XML vocabulary may need to add
a little bit more of code? Or have I overlooked a "killer" argument against?

  thanks in advance

  lyndon

<element name="MyXML">
       <complexType>
          <sequence>
             <element name="Part1" minOccurs="0">
                ...
             </element>
            <element name="Part2" minOccurs="0">
                <complexType>
                   <choice minOccurs="0" maxOccurs="unbounded">
                      <element ref="PartsInventory"/>
                   </choice>
                </complexType>
             </element>
          </sequence>
       </complexType>
    </element>

     <element name="PartsInventory">
       <complexType>
          <all>
             <element ref="Part1" minOccurs="0"/>
             <element ref="Part2" minOccurs="0"/>
          </all>
       </complexType>
    </element>

    <element name="Part1">
                ...
    </element>

    <element name="Part2">
                ...
    </element>


Lyndon J B Nixon ... MAGIC Centre, FHG FOKUS ... Berlin, Germany
"what is now proved was once only imagined" - william blake
PhD Student, Integration of Internet with MPEG-4 & MPEG-7

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