[Tutor] Injecting Data into XML Files

[William O'Higgins Witteman]

I am wrestling with the incredibly vast array of XML parsing and writing
documentation, and I'm not seeing (or perhaps not understanding) what
I'm looking for.  Here's the situation:

I have a large number of XML documents to add data to.  They are
currently skeletal documents, looking like this:

<?xml version="1.0" ?>
<!DOCTYPE rdf:RDF SYSTEM "local.dtd">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
   <rdf:Description rdf:about="local_file">
      <tagname></tagname>
      <anothertagname></anothertagname>
      ...

What I want is to open each document and inject some data between
specific sets of tags.  I've been able to parse these documents, but I am
not seeing how to inject data between tags so I can write it back to the
file.  Any pointers are appreciated.  Thanks.
-- 

yours,

William