XSLT - replace value in one node with the value from it's preceeding sibling

Question

Hi There, I'm trying to write an XSLT transformation which will replace the value in one node with the value of it's preceding sibling. Then return the entire document transformed :)

Find the occurrences of

<package:packageDownloadLocator>http://myunwantedurl&lt;/package:packageDownloadLocator&gt;

and replace with the text value of it's proceeding sibling

<package:packagePreviewLocator>http://myurl.com&lt;/package:packagePreviewLocator&gt;

Thanks for any help or suggestions

Note: The node to be found does not always exist in each record.

From this:

    <?xml version="1.0"?>
<SRW:searchRetrieveResponse xmlns:SRW="http://www.loc.gov/zing/srw/" xmlns:DIAG="http://www.loc.gov/zing/srw/diagnostics" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:package="info:srw/extension/13/package-v1.0">
<SRW:records>
<SRW:record>
   <SRW:recordData>
    <dc:dc>
     <dc:title xml:lang="en">Opportunities for involvement for service users and carers at the Open University in Scotland</dc:title>
     <dc:description xml:lang="en">Booklet explaining the different ways service users or carers can assist</dc:description>
     <dc:publisher>Open University</dc:publisher>
     <dc:format>application/pdf</dc:format>
     <dc:type>Narrative Text</dc:type>
     <dc:rights xml:lang="en">Copyright Open University, 2009</dc:rights>
     <dc:subject>health and health care, health care, nursing</dc:subject>
    </dc:dc>
   </SRW:recordData>
   <SRW:extraRecordData>
    <package:packagePreviewLocator>http://myurl.com&lt;/package:packagePreviewLocator&gt;
    <package:packageDownloadLocator>http://myunwantedurl&lt;/package:packageDownloadLocator&gt;
    <record:record xmlns:record="http://srw.o-r-g.org/schemas/rec/1.0/"&gt;
     <record:lastModified>2009-09-29</record:lastModified>
     <record:created>2009-09-29</record:created>
    </record:record>
   </SRW:extraRecordData>
  </SRW:record>
 </SRW:records>
</SRW:searchRetrieveResponse>

To this:

<?xml version="1.0"?>
<SRW:searchRetrieveResponse xmlns:SRW="http://www.loc.gov/zing/srw/" xmlns:DIAG="http://www.loc.gov/zing/srw/diagnostics" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:package="info:srw/extension/13/package-v1.0">
<SRW:records>
<SRW:record>
   <SRW:recordData>
    <dc:dc>
     <dc:title xml:lang="en">Opportunities for involvement for service users and carers at the Open University in Scotland</dc:title>
     <dc:description xml:lang="en">Booklet explaining the different ways service users or carers can assist</dc:description>
     <dc:publisher>Open University</dc:publisher>
     <dc:format>application/pdf</dc:format>
     <dc:type>Narrative Text</dc:type>
     <dc:rights xml:lang="en">Copyright Open University, 2009</dc:rights>
     <dc:subject>health and health care, health care, nursing</dc:subject>
    </dc:dc>
   </SRW:recordData>
   <SRW:extraRecordData>
    <package:packagePreviewLocator>http://myurl.com&lt;/package:packagePreviewLocator&gt;
    <package:packageDownloadLocator>http://myurl.com&lt;/package:packageDownloadLocator&gt;
    <record:record xmlns:record="http://srw.o-r-g.org/schemas/rec/1.0/"&gt;
     <record:lastModified>2009-09-29</record:lastModified>
     <record:created>2009-09-29</record:created>
    </record:record>
   </SRW:extraRecordData>
  </SRW:record>
 </SRW:records>
</SRW:searchRetrieveResponse>

Answer 1

Read up on the "Identity Transformation" (Google it, there's a good page at Wikipedia). All you need is an identity transform plus a template that matches the tag you want to change. You'll also have to decide if you want any preceding sibling, or a specific preceding tag (and what to do if there's no preceding sibling).