Trying to use XML::Twig

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

I might be approaching my problem from a remedial point of view. I have included a simple example xml file similar to my real data file. I have a simple working perl script to read it. My problem arises because I have a varying number of products under each group. I can use first_child to get the first one, but I don't know how to get each 'product' after that. From the documentation, I decided to determine how many of them there are using within_element.

The documentation also says you must use generate_ns_name(NAME,URI) to define $gs. I can't find an example of calling generate_ns_name or within_element.

My xml file looks like this:
========company.xml=======
<comany>
<group>
    <name>dev group 1</name>
    <product>product 1</product>
    <product>product 2</product>
    <product>product 3</product>
    <product>product 4</product>
</group>
<group>
    <name>dev group 2</name>
    <product>product 1</product>
    <product>product 2</product>
</group>
</company>
[download]

========company.pl========
#!/bin/perl -w

use strict;
use XML::Twig;

my $field= 'group';

my $twig= new XML::Twig;

$twig->parsefile( "company.xml"); # build the twig

my $root= $twig->root;            # get the root of the twig
my @group = $root->children;      # get the list

foreach my $my_group (@group)     # the sorted list
{ 
   print "\nGroup Name: ",$my_group->first_child("name")->text;
   print "\nGroup Name: ",$my_group->first_child("product")->text;
}
================
[download]

Thanks,
Patrick
patrick_breithaupt( at )mentorg.com

Edit kudra, 2001-09-24 Removed cpde tags around text

Comment on Trying to use XML::Twig Select or Download Code

Replies are listed 'Best First'.
Re: Trying to use XML::Twig by mirod (Canon) on Sep 21, 2001 at 20:11 UTC
To find out how many `product` are in $nameyou can just do `my $nb_product= $name->children( 'product');` (that's `children` in scalar context, in list context you would of course get the list of `product` children). As for the name space question could you please explain a little more what you want to do and what you have tried so far, I am pretty sure there is nothing about name spaces in the XML::Twig documentation. This post brought to you courtesy of tonio	[reply] [d/l]
Re: Re: Trying to use XML::Twig by Novitiatus (Novice) on Sep 21, 2001 at 21:41 UTC
Thanks, I'm back from eating my gruel... http://www.standards.ieee.org/resources/spasystem/twig/twig_dev.html That is where I saw the within_element($gi) Call Expat within_element method. Returns the number of times the given name appears in the context list. If namespace processing is being used and you want to check against a name that may be in a namespace, then use the generate_ns_name method to create the $gi argument. Usefull when using the TwigRoots option.	[reply]
Re: Re: Re: Trying to use XML::Twig by mirod (Canon) on Sep 21, 2001 at 22:03 UTC
Consider this a bad case of cut'n paste. The doc for `within_element` is from the original XML::Parser::Expat method. In fact this method should only be used during the parsing, if you are using the `twig_roots` option, to get information about the original document, not the view on it defined by `twig_roots`... if that makes any sense. Basically you should use `$elt->ancestors( $gi)` in scalar context to getthe number of ancestors of type `$gi` for the element $elt. Which does not look like what you wanted anyway ;--( Thanks for letting me know about this silly documentation bit though, I will fix it in the next release.	[reply]