Template::TAL::ValueParser - parse attribute values

Template-TAL documentation Contained in the Template-TAL distribution.

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NAME

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Template::TAL::ValueParser - parse attribute values

SYNOPSIS

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  my $string = "path:/foo/bar/0/baz";
  my $value = Template::TAL::ValueParser->value( $string );

DESCRIPTION

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This module is responsible for parsing the values of attributes in templates, and returning them. It can also split multiple values up into a list, using semicolons as list seperators. The way that values are parsed is based very strongly on TALES (http://www.zope.org/Wikis/DevSite/Projects/ZPT/TALES) but the actual TALES spec is provided by the language module Template::TAL::Language::TALES.

METHODS

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split( string )

commands in 'string' can be split by ';' characters, with raw semicolons represented as ';;'. This command splits the string on the semicolons, and de-escapes the ';;' pairs. For instance:

  foo; bar; baz;; narf

splits to:

  ['foo', 'bar', 'baz; narf']

Not technically part of TALES, I think, but really useful for TAL anyway.

value( expression, context arrayref, plugin arrayref )

parse a TALES expression in the first param, such as

  string:Hello there
  path:/a/b/c

using the passed contexts (in order) to look up path values. Contexts should be hashes, and we will look in each context for a defined key of the given path until we find one.

(note - I need the multiple contexts code because TAL lets you set globals in define statements, so I need a local context, and a global context)

The plugins value should be an arrayref of language plugins to ask about the various types of string. At a minimum, this should probably include Template::TAL::Language::TALES, or the module won't do a lot.

COPYRIGHT

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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.

Template-TAL documentation Contained in the Template-TAL distribution. 
package Template::TAL::ValueParser;
use warnings;
use strict;
use Carp qw( croak );


sub split {
  my ($class, $string) = @_;
  # TODO this is _hokey_. Do it properly.
  $string =~ s/;;/\x{12345}/g;
  my @list = grep {$_} split(/\s*;\s*/, $string);
  s/\x{12345}/;/g for @list;
  return @list;
}


sub value {
  my ($class, $exp, $contexts, $plugins) = @_;
  Carp::croak("contexts must be arrayref, not ".ref($contexts)) unless ref($contexts) eq 'ARRAY';
  my ($type, $string) = $exp =~ /^\s*(?:(\w+):\s*)?(.*)/;
  $type ||= "path";
  my $sub = "process_tales_$type";
  for my $plugin (@{ $plugins || [] }) {
    if ($plugin->can($sub)) {
      return $plugin->$sub($string, $contexts, $plugins );
    }
  }
  die "unknown TALES type '$type'\n";
}


1;