Perl and XPath.

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

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>
[download]

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"; }
[download]

Output:

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

 author="jdporter"

 author="jdporter"


C:\Perl\bin>
[download]

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

Thanks,
~Katie

Comment on Perl and XPath. Select or Download Code

Replies are listed 'Best First'.

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"; }
[download]

[reply]
[d/l]

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";
    }
[download]

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

[reply]
[d/l]

Re: Perl and XPath.
by Jenda (Abbot) 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!

[reply]
[d/l]

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(;;);

[reply]
[d/l]

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

[reply]


Keep It Simple, Stupid
	PerlMonks