XPath search qn

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

Hi perl monks. I have an XML file as below, storing attributes of a list of files.


<file>
<name>test.doc</name>
<userprop>
  <nameprop>Effective Date</nameprop> 
  <valueprop>16-Dec-2003</valueprop> 
</userprop>
<userprop>
  <nameprop>Owner</nameprop> 
  <valueprop>Adrian.Johnston</valueprop> 
</userprop>
<userprop>
  <nameprop>Version</nameprop> 
  <valueprop>v1.3</valueprop> 
</userprop>
</file>
<file>
...
</file>
[download]

So if I would require all the files with version "v1.3", I would have to extract all "nameprop" nodes as below, and if the string is "Version", i'll get the equivalent string of valueprop and then do a comparison.

my $nodeset = $xpath->find('//file/userprop/nameprop');
...
$valu_node = $xpath->find('../valueprop',$node)->get_node(1);
[download]

However, if the XML for userprops was stored as attributes as below :


<userprop name="Version">v1.3</userprop>
[download]

Then, I could have taken easier XPath search of :


my $nodeset = $xpath->find('//file/userprop/[@name='v1.3]');
[download]

to derive all the version nodes. And then if they are "v1.3", I print out the file name. So qn is, is there any simple way to use XPath if my XML format is using sub-elements for "userprop", as in the first listing above. Thanks.

Comment on XPath search qn Select or Download Code

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Re: XPath search qn by pizza_milkshake (Monk) on May 05, 2004 at 05:38 UTC
well, i figured out a way to perform tests on more than one child node, but it ain't pretty. i'd stick with attributes. update: updated the path to suck less. i learned a decent amount about xpath by doing this! :) #!perl -l use strict; use warnings; use XML::XPath; my $xp = XML::XPath->new("xml" => do { undef $/; <DATA> }); my $path = q{//userprop[nameprop='Version' and valueprop='v1.3']/ances +tor::file}; my $nodes = $xp->find($path); for my $node ($nodes->get_nodelist) { print XML::XPath::XMLParser::as_string($node); } __DATA__ <files> <file> <name>test.doc</name> <userprop> <valueprop>v1.3</valueprop> <nameprop>Version</nameprop> </userprop> </file> <file> <name>test.doc</name> <userprop> <nameprop>Version</nameprop> <valueprop>v1.4</valueprop> </userprop> </file> </files> [download] perl -e"\$_=qq/nwdd\x7F^n\x7Flm{{llql0}qs\x14/;s/./chr(ord$&^30)/ge;print"	[reply] [d/l]
Re: Re: XPath search qn by Justudo (Novice) on May 05, 2004 at 08:08 UTC
I'd stick to attributes too if I had a choice! :) But your code is useful. Thanks. However, what if I want to do something like a wildcard search on 'v1.3' or 'v1.31' etc. ? I tried : `my $nodes = $xp->find(q{/files/file/userprop/nameprop[text()='Version' +]/../valueprop[text()='v1.3\|v1.31']/ancestor::file});` [download] AND `my $nodes = $xp->find(q{/files/file/userprop/nameprop[text()='Version' +]/../valueprop[text()='v1.3*']/ancestor::file});` [download] Both did not work. Is it also possible to do a range search ? Like substr(text(),1,2) > 1.3 to get all version greater than 'v1.3'. Or even a date search ?	[reply] [d/l] [select]
Re: XPath search qn by dakkar (Hermit) on May 05, 2004 at 12:08 UTC
`//file[userprop[nameprop='Version']/valueprop=2]` [download] Which means: take every `file` element whose `userprop` child (whose `nameprop` child has a content of `'Version'`) has a `valueprop` child with a content of `2` Or, put more clearly, you can nest node-tests (the things inside the brackets) -- dakkar - Mobilis in mobile Most of my code is tested... Perl is strongly typed, it just has very few types (Dan)	[reply] [d/l]
Re: Re: XPath search qn by pizza_milkshake (Monk) on May 05, 2004 at 14:16 UTC
ah, i'd been looking for the ability to perform more than one test at the same level and not finding it. i will update my code. thanks! perl -e"\$_=qq/nwdd\x7F^n\x7Flm{{llql0}qs\x14/;s/./chr(ord$&^30)/ge;print"	[reply]