XSLT, 2nd Edition

Linking Parts of an XML Document

To illustrate the value of linking, we’ll use a document that defines several <component> and <part> elements. Each <component> uses some number of <part>s. Because our XML document contains ID and IDREF values, we can link different parts of the document together.

Here’s how our document looks:

<?xml version="1.0"?>
<!-- parts-list1.xml -->
<!DOCTYPE parts-list [
...
]>

<parts-list>
  <component component-id="C28392-33-TT">
    <name>Turnip Twaddler</name>
    <partref refid="P81952-26-PK"/>
    <partref refid="P86679-52-SP"/>
    <partref refid="P81472-68-FD"/>
    <partref refid="P88107-39-GT"/>
  </component>
...
  <component component-id="C28772-63-OB">
    <name>Olive Bruiser</name>
    <partref refid="P80228-21-PT"/>
    <partref refid="P82387-85-PA"/>
  </component>

  <part part-id="P80228-21-PT">
    <name>Pitter</name>
  </part>
...
  <part part-id="P86994-25-RC">
    <name>Ribbon Curler</name>
  </part>
</parts-list>

Our first task will be to look at each <component> and list the names of the <part>s that it uses. Each of the refid attributes of each of the <partref> elements refers to the id attribute of a <part> element.