XML::Twig ignore_elts

[anniyan]

Monks, I have some problem in my coding.

I have the following xml as a input and in that i just want to change the 'title' element with 'tit' everywhere except second sub level title, in the below example it is the title that contains 'second sub level', which should not be changed.

For the above job i tried using ignore_elts method but it converts all the title into tit and when i saw the output it is missing, but i just want the text back in the ouput as i shown below. How to do this?

use strict;
use XML::Twig;

my $sel = 'title';
my $ign = 'title/title/title';
my $twig = XML::Twig->new(
ignore_elts => { "$ign" => 1},
twig_handlers => { "$sel" => \&title},
pretty_print => 'indented'
);

$twig->parsefile('1.xml');

$twig->print;

sub title
{
    my ($twig, $tit) = @_;
    
    $tit->set_gi('tit');
    
}

input:
<?xml version="1.0"?>
<!DOCTYPE stats SYSTEM "stats.dtd">
<stats>
<title id="1">testing<name><snm>Houston</snm>, <fnm>Allan</fnm></name>
+<g>69</g><ppg>20.1</ppg><rpg>3.4</rpg><apg>2.8</apg><blk>14</blk></ti
+tle>
<title id="2">testing<name><snm>Houston</snm>, <fnm>Allan</fnm></name>
+<g>69</g><ppg>20.1</ppg><rpg>3.4</rpg><apg>2.8</apg><blk>14</blk></ti
+tle>
<title id="3">
<name1>Raja m</name1><g>49</g>
    <title>
    testing the sub title in title
    </title>
    <title>
    this is pcdata in subtitle
        <title>
        second sub level
        </title>
    </title>
</title>
</stats>

output:
<?xml version="1.0"?>
<!DOCTYPE stats SYSTEM "stats.dtd">
<stats>
  <tit id="1">testing<name><snm>Houston</snm>, <fnm>Allan</fnm></name>
+<g>69</g><ppg>20.1</ppg><rpg>3.4</rpg><apg>2.8</apg><blk>14</blk></ti
+t>
  <tit id="2">testing<name><snm>Houston</snm>, <fnm>Allan</fnm></name>
+<g>69</g><ppg>20.1</ppg><rpg>3.4</rpg><apg>2.8</apg><blk>14</blk></ti
+t>
  <tit id="3">
    <name1>Raja m</name1>
    <g>49</g>
    <tit>
    testing the sub title in title
    </tit>
    <tit>
    this is pcdata in subtitle
        </tit>
  </tit>
</stats>

Expected output:
<?xml version="1.0"?>
<!DOCTYPE stats SYSTEM "stats.dtd">
<stats>
  <tit id="1">testing<name><snm>Houston</snm>, <fnm>Allan</fnm></name>
+<g>69</g><ppg>20.1</ppg><rpg>3.4</rpg><apg>2.8</apg><blk>14</blk></ti
+t>
  <tit id="2">testing<name><snm>Houston</snm>, <fnm>Allan</fnm></name>
+<g>69</g><ppg>20.1</ppg><rpg>3.4</rpg><apg>2.8</apg><blk>14</blk></ti
+t>
  <tit id="3">
    <name1>Raja m</name1>
    <g>49</g>
    <tit>
    testing the sub title in title
    </tit>
    <tit>
    this is pcdata in subtitle
        <title>
         second sub level
        </title>
   </tit>
  </tit>
</stats>

[Tanktalus]

The ignore_elt parameter doesn't do what you think it does. It tells XML::Twig to pretend that element doesn't even exist. So what you want is to remove that, and then inside the title function, check where you're at. One way is this:

my $twig = XML::Twig->new(
                          twig_handlers => { $sel => \&title},
                          pretty_print => 'indented'
                         );
# ...
sub title
{
    my ($twig, $tit) = @_;

    $tit->set_gi('tit') unless $tit->level('title') == 2;
}

This means XML::Twig will read and parse the title/title/title elements, but when we get there, we check how many levels of title's there are above us, and if that is 2 (that means we're the 3rd), then we don't set_gi.

Good luck.

[mirod]

As Tanktalus mentioned, you cannot use ignore_elt for this.

An other way to do this is to set a twig handler on 'title/title/title' that will just return 0, this will prevent the handler on title to be run:

my $twig = XML::Twig->new( twig_handlers => { $ign => sub { return 0},
                                              $sel => \&title,
                                            },

[anniyan]

mirod that works fine. thank you. Tanktalus thanks for your contribution as well.