Perl and XPath.

Hi all.

I'm currently in the process of teaching myself how to use XPath and Perl to parse XML documents (most notably, the chatterbox feed). After reading the documentation, I felt compelled to inquire about removing the attribute name in the output (please see below):

<?xml version="1.0" encoding="ISO-8859-1"?>
<CHATTER>
<INFO site="http://perlmonks.org/" sitename="PerlMonks" ticker_id="158
+34" gentimeGMT="2007-01-05 
23:29:59" xmlstyle="old" xmlmaker="XML::Fling 1.001" count="3" lastid=
+"419432">
Rendered by the Chatterbox XML Ticker</INFO>
<message user_id="22609" author="tye" time="20070105182057">
is "this proxy" that you mentioned relatively new?</message>
<message user_id="170442" author="jdporter" time="20070105182124">
is that a problem?</message>
<message user_id="170442" author="jdporter" time="20070105182217">
oh, sorry. yes, looks like [merlyn|he] is having a problem.</message>
</CHATTER>
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By using the short program provided by the module's author and what I had already gleaned from various online tutorials, I was able to display the value of each 'author' attribute:

#!/usr/bin/perl
use warnings;
use strict;

use XML::XPath;
use XML::XPath::XMLParser;
    
    my $xp = XML::XPath->new(filename => 'pm.xml');
    
    my $nodeset = $xp->find('//@author'); # find all authors
    
    foreach my $node ($nodeset->get_nodelist) {
        print XML::XPath::XMLParser::as_string($node), "\n\n"; } 
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Output:

C:\Perl\bin>perl test.pl
 author="tye"

 author="jdporter"

 author="jdporter"


C:\Perl\bin>
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Is there a method I'm unaware of that will display only the value(s) and omit the atttribute 'name='(?)

Thanks,
~Katie

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Re: Perl and XPath.
by jettero (Monsignor) on Jan 06, 2007 at 01:02 UTC

I use the following in a project (real path obscured):

    for my $pattern ($path->findnodes("thingy/something", $top)) {
        my $file = $path->findvalue('@file',   $pattern)->value;
        my $num  = $path->findvalue('@number', $pattern)->value;

        print "number is $num and file is $file\n";
    }
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If there's a better way, I'd like to know it. I find the XML::XPath to be a little awkward to use, but I think I'm missing something.

-Paul

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Re: Perl and XPath.
by duckyd (Hermit) on Jan 06, 2007 at 01:09 UTC


    foreach my $node ($nodeset->get_nodelist) {
        print $node->getNodeValue, "\n\n"; }

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Re: Perl and XPath.
by murugu (Curate) on Jan 07, 2007 at 08:55 UTC

#!/usr/bin/perl
use warnings;
use strict;
my $a = do {local $/; <DATA>};

use XML::XPath;
use XML::XPath::XMLParser;
    
    my $xp = XML::XPath->new(xml => $a);
    
    my $nodeset = $xp->find('//@author'); # find all authors
    

    foreach my $node ($nodeset->get_nodelist) {
        print $node->getNodeValue."\n\n"; } 
[download]

Regards,
Murugesan Kandasamy
use perl for(;;);

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Re^2: Perl and XPath.

by Anonymous Monk on Aug 02, 2007 at 22:00 UTC

Is it possible to use getNodeValue if you want to get values from multiple attributes at a single level in the tree. For example <id = "2" name = "Jim" Date = "Today" > So in my $node variable I have all of the values. How can I use getNodeValue to access them individually

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Re: Perl and XPath.
by Jenda (Monsignor) on Jan 08, 2007 at 00:27 UTC

use XML::Rules;
my $parser = XML::Rules->new(
 rules => {
  message => sub {
    print $_[1]->{author}, "\n\n";
   }
 }
);
$parser->parse('pm.xml');
[download]

Oh, you wanted XPath, never mind ;-)

Jenda
Support Denmark!
Defend the free world!

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