XML parser that sorts elements?

[jmike at alum.mit.edu]

Hi everyone,

I am a total newbie to XML parsing.  I've written a couple of toy
examples under the instruction of tutorials available on the web.

The problem I want to solve is this.  I have an XML snippet (in a
string) that looks like this:

<booga foo="1" bar="2">
  <well>hello</well>
  <blah>goodbye</blah>
</booga>

and I want to alphabetize not only the attributes of an element, but I
also want to alphabetize the elements in the same scope:

<booga bar="2" foo="1">
  <blah>goodbye</blah>
  <well>hello</well>
</booga>

I've found a "Canonizer" class, that subclasses saxlib.HandlerBase, and
played around with it and vaguely understand what it's doing.  But what
I get out of it is

<booga bar="2" foo="1">
  <well>hello</well>
  <blah>goodbye</blah>
</booga>

in other words it sorts the attributes of each element, but doesn't
touch the order of the elements.

How can I sort the elements?  I think I want to subclass the parser, to
present the elements to the content handler in different order, but I
couldn't immediately find any examples of the parser being subclassed.

Thanks for any pointers!
  --JMike