http://www.perlmonks.org?node_id=28388

doran has asked for the wisdom of the Perl Monks concerning the following question:

I have some XML files stored. Occasionally, I'll receive "update" XML files from other machines. I need to replace the content of existing nodes (and their children) with the incoming update. I don't need to keep any existing data in the replaced nodes, but I do need to keep the data in any other nodes. Also, I need to keep the order of the tags in the updated file the same as in the original file.

Here's an example of the results I'm looking for. In it, I want to update everything in the <jobs> node and below.

Given this "old" XML:

<root> <info> <name>Joe Bleugh</name> <badge_id>1234</badge_id> <phone_ext>987</phone_ext> </info> <jobs> <chore> <desc>Wash Dishes</desc> <due>8-17-2000</due> </chore> <chore> <desc>Paint House</desc> <due>9-20-2000</due> </chore> </jobs> </root>
And this Update:
<root> <info> <badge_id>1234</badge_id> </info> <jobs> <chore> <desc>Mow Lawn</desc> <due>8-20-2000</due> </chore> <chore> <desc>Buy Car</desc> <due>10-1-2000</due> </chore> </jobs> </root>
I want to produce:
<root> <info> <name>Joe Bleugh</name> <badge_id>1234</badge_id> <phone_ext>987</phone_ext> </info> <jobs> <chore> <desc>Mow Lawn</desc> <due>8-20-2000</due> </chore> <chore> <desc>Buy Car</desc> <due>10-1-2000</due> </chore> </jobs> </root>
Where none of the data outside the <jobs> node gets altered, but everything within it does get replaced.

So my question isn't whether it can be done (of course it can) but rather about what's the best, easiest way of doing it. XML::Simple doesn't seem quite robust enough, whereas XML::Parser doesn't make it too easy. XML::Twig looks like it can do this, but my eyes started to cross after a couple of pages worth of docs. Before I went too much further reading anything at CPAN with the letters XML attached, I thought I'd ask here and see what y'all thought. Is there a module that's particularly well suited for this or do I just need to sit down with a Big Brew and write a bunch of subroutines for XML:Parser to go through?

Thanks, of course, for any insights.
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