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

Dear wise monks ... I pull out a couple of lists if ip address from my XML data 
my $xp                  = XML::XPath->new(xml => $fpdomaininfo );
my $nodeset             = $xp->find('//cidr-map');
foreach my $node ($nodeset->get_nodelist) {
        my $node_name           = $node->findvalue ( '@name' ) -> stri
+ng_value;
        my $ips_as_string       = $node->string_value;
... make changes to ips_as_string ...
}

[download]
Then I make changes to these list, then I want to put the data back into my xml data, but I cannot figure out what path I am suppose to use in the setNodeText call. I have tried this like ... 
my $path = '//cidr-map[@name]=';
$path .= "\"$node_name\";
$xp->setNodeText( $path, $ips_as_string );

[download]
... and ... 
my $path = '//cidr-map/cidr-map-to[@name]=';
$path .= "\"$node_name\";
$xp->setNodeText( $path, $ips_as_string );

[download]
... the xml looks like this ... 
...
<cidr-map name="Internal test" default-datacenter="Default Datacenter"
+>
<cidr-map-to name="AKA Edge">
<blocks>127.0.241.174 127.0.0.181</blocks>
</cidr-map-to>
</cidr-map>
<cidr-map name="Prod Internal Actual" default-datacenter="Default Data
+center">
<cidr-map-to name="AKA Edge">
<blocks>127.0.12.1 10.0.0.1 198.168.1.1</blocks>
</cidr-map-to>
</cidr-map>
...

[download]
.. and other ham fist-ed attempts while I grasp at straws. I cannot figure out for the life me what $path I should use in the setNodeText call. Can you all help? Thanks!

Replies are listed 'Best First'.
Re: Trouble using setNodeText()
by wind (Priest) on Apr 06, 2011 at 20:15 UTC
    Using XML::Twig, the below script takes your ip blocks and reverses their order: 
    use XML::Twig;
use strict;

my $xml = do {local $/; <DATA>};

my $twig = XML::Twig->new(
    keep_spaces => 1,
);
$twig->parse($xml);

foreach my $node ($twig->findnodes(q{//cidr-map-to[@name='AKA Edge']/b
+locks})) {
    $node->set_text(join ' ', reverse split ' ', $node->text());
}

$twig->print();

__DATA__
<root>
<cidr-map name="Internal test" default-datacenter="Default Datacenter"
+>
<cidr-map-to name="AKA Edge">
<blocks>127.0.241.174 127.0.0.181</blocks>
</cidr-map-to>
</cidr-map>
<cidr-map name="Prod Internal Actual" default-datacenter="Default Data
+center">
<cidr-map-to name="AKA Edge">
<blocks>127.0.12.1 10.0.0.1 198.168.1.1</blocks>
</cidr-map-to>
</cidr-map>
</root>

    [download]
[reply]
[d/l]
Re: Trouble using setNodeText()
by Anonymous Monk on Apr 06, 2011 at 21:00 UTC
    . and other ham fist-ed attempts while I grasp at straws. I cannot figure out for the life me what $path I should use in the setNodeText call.

    Small program to test one function, like (this should probably be 3 different programs) 

    #!/usr/bin/perl --

use strict;
use warnings;

use XML::XPath;

Main( @ARGV );
exit( 0 );

sub Main {
    use XML::XPath;

    my $xc = XML::XPath->new(xml  => SampleXML() );
    print "ORIGINAL XML\n";
    print $xc->findnodes_as_string('/'), "\n\n";
    
    print "//blocks MATCHES MANY NODES \n";
    $xc->setNodeText( '//blocks', ' blah blah ' );
    print $xc->findnodes_as_string('/'), "\n\n";
    
    print '//cidr-map-to[@name="AKA Edge"]/blocks MATCHES MANY NODES',
+ "\n";
    $xc->setNodeText( '//cidr-map-to[@name="AKA Edge"]/blocks', ' aha 
+42 ' );
    print $xc->findnodes_as_string('/'), "\n\n";
    
    print '//cidr-map[2]/cidr-map-to/blocks  MATCHES ONE NODE', "\n";
    $xc->setNodeText( '/Product/cidr-map[2]/cidr-map-to/blocks', ' eur
+eka ' );
    $xc->setNodeText( '//cidr-map[2]/cidr-map-to/blocks', ' eureka ' )
+;
    $xc->setNodeText( '//cidr-map[@name="Prod Internal Actual"]/cidr-m
+ap-to/blocks', ' eureka ' );
    
    print $xc->findnodes_as_string('/'), "\n\n";
}


sub SampleXML {
    return <<'__XML__';
<?xml version="1.0"?>
<Product>
  <cidr-map default-datacenter="Default Datacenter" name="Internal tes
+t">
    <cidr-map-to name="AKA Edge">
      <blocks>127.0.241.174 127.0.0.181</blocks>
    </cidr-map-to>
  </cidr-map>
  <cidr-map default-datacenter="Default Datacenter" name="Prod Interna
+l Actual">
    <cidr-map-to name="AKA Edge">
      <blocks>127.0.12.1 10.0.0.1 198.168.1.1</blocks>
    </cidr-map-to>
  </cidr-map>
</Product>
__XML__
}

__END__
ORIGINAL XML
<Product>
  <cidr-map default-datacenter="Default Datacenter" name="Internal tes
+t">
    <cidr-map-to name="AKA Edge">
      <blocks>127.0.241.174 127.0.0.181</blocks>
    </cidr-map-to>
  </cidr-map>
  <cidr-map default-datacenter="Default Datacenter" name="Prod Interna
+l Actual">
    <cidr-map-to name="AKA Edge">
      <blocks>127.0.12.1 10.0.0.1 198.168.1.1</blocks>
    </cidr-map-to>
  </cidr-map>
</Product>

//blocks MATCHES MANY NODES 
<Product>
  <cidr-map default-datacenter="Default Datacenter" name="Internal tes
+t">
    <cidr-map-to name="AKA Edge">
      <blocks> blah blah </blocks>
    </cidr-map-to>
  </cidr-map>
  <cidr-map default-datacenter="Default Datacenter" name="Prod Interna
+l Actual">
    <cidr-map-to name="AKA Edge">
      <blocks> blah blah </blocks>
    </cidr-map-to>
  </cidr-map>
</Product>

//cidr-map-to[@name="AKA Edge"]/blocks MATCHES MANY NODES
<Product>
  <cidr-map default-datacenter="Default Datacenter" name="Internal tes
+t">
    <cidr-map-to name="AKA Edge">
      <blocks> aha 42 </blocks>
    </cidr-map-to>
  </cidr-map>
  <cidr-map default-datacenter="Default Datacenter" name="Prod Interna
+l Actual">
    <cidr-map-to name="AKA Edge">
      <blocks> aha 42 </blocks>
    </cidr-map-to>
  </cidr-map>
</Product>

//cidr-map[2]/cidr-map-to/blocks  MATCHES ONE NODE
<Product>
  <cidr-map default-datacenter="Default Datacenter" name="Internal tes
+t">
    <cidr-map-to name="AKA Edge">
      <blocks> aha 42 </blocks>
    </cidr-map-to>
  </cidr-map>
  <cidr-map default-datacenter="Default Datacenter" name="Prod Interna
+l Actual">
    <cidr-map-to name="AKA Edge">
      <blocks> eureka </blocks>
    </cidr-map-to>
  </cidr-map>
</Product>

    [download]
    Read http://w3schools.com/xpath/default.asp for gentle introduction to xpath.
[reply]
[d/l]

Back to Seekers of Perl Wisdom