/ 
Template-TAL-0.91
River stage zero No dependents
/ Template::TAL::Language

NAME

Template::TAL::Language - base class for Template::TAL languages

SYNOPSIS

my $tal = Template::TAL->new();
$tal->add_language(MyLanguage->new);
$tal->process( $template, $data );

DESCRIPTION

To be as flexible as possible, the tag handling in Template::TAL is implemented as Language modules, which declare the namespace and the tags that they wish to handle, and are called from the 'process_tag_node' method of Template::TAL::Template. So far, there is only one implemented language, Template::TAL::Language::TAL, and there is no easy way of changing which languages are loaded by Template::TAL in it's normal use, though I expect this to change in the near future. Specifically, when Template::TAL::Language::METAL is ready, support for adding Language modules will get a lot better.

SUBCLASSING

Assuming you want to create a new Language, subclass this module, and override the namespace and tags methods, and provide process_tag_XXX methods for every tag your language contains. For instance:

package MyLanguage;
use base qw( Template::TAL::Language );

sub namespace { 'http://foo.bar' }
sub tags {qw( bar )}
sub process_tag_bar {
  my ($self, $parent, $element, $value, $local_context, $global_context);
  return (); # just remove the node
}

When loaded, this will apply to the template

<html xmlns:test="http://foo.bar">
  <fred test:bar="1">this element will be removed</fred>
</html>

METHODS

Override these methods in a subclass

new()

creates a new instance

namespace

return the namespace of the tags this module implements

tags

return a list of tags in that namespace, in processing order, that this module handles.

process_tag_<tagname>( caller, element, value, local_context, global_context )

called to process tags with the given tagname. The params are

element - the XML::LibXML::Element being processed
value - the string value of the attribute
local_context - the local context hash, use this for preference
global_context - the global context hash

Certian tag names, eg 'omit-tag', contain '-' characters, which will be converted to '_' characters for the method call, so define process_tag_omit_tag { .. }.

COPYRIGHT

Written by Tom Insam, Copyright 2005 Fotango Ltd. All Rights Reserved

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.