Template::Parser(3pm)

NAME
Template::Parser - LALR(1) parser for compiling template documents

SYNOPSIS
    use Template::Parser;

    $parser   = Template::Parser->new(\%config);
    $template = $parser->parse($text)
        || die $parser->error(), "\n";

DESCRIPTION
The "Template::Parser" module implements a LALR(1) parser and associated methods for parsing template documents into Perl code.

PUBLIC METHODS

  new(\%params)
The new() constructor creates and returns a reference to a new "Template::Parser" object.

A reference to a hash may be supplied as a parameter to provide configuration values. See "CONFIGURATION OPTIONS" below for a summary of these options and Template::Manual::Config for full details.

    my $parser = Template::Parser->new({
        START_TAG => quotemeta('<+'),
        END_TAG   => quotemeta('+>'),
    });

  parse($text)
The parse() method parses the text passed in the first parameter and returns a reference to a hash array of data defining the compiled representation of the template text, suitable for passing to the Template::Document new() constructor method. On error, undef is returned.

    $data = $parser->parse($text)
        || die $parser->error();

The $data hash reference returned contains a "BLOCK" item containing the compiled Perl code for the template, a "DEFBLOCKS" item containing a reference to a hash array of sub-template "BLOCK"s defined within in the template, and a "METADATA" item containing a reference to a hash array of metadata values defined in "META" tags.

CONFIGURATION OPTIONS
The "Template::Parser" module accepts the following configuration options. Please see Template::Manual::Config for further details on each option.

  START_TAG, END_TAG
The START_TAG and END_TAG options are used to specify character sequences or regular expressions that mark the start and end of a template directive.

    my $parser = Template::Parser->new({
        START_TAG => quotemeta('<+'),
        END_TAG   => quotemeta('+>'),
    });

  TAG_STYLE
The TAG_STYLE option can be used to set both START_TAG and END_TAG according to pre-defined tag styles.

    my $parser = Template::Parser->new({
        TAG_STYLE => 'star',     # [* ... *]
    });

  PRE_CHOMP, POST_CHOMP
The PRE_CHOMP and POST_CHOMP can be set to remove any whitespace before or after a directive tag, respectively.

    my $parser = Template::Parser-E<gt>new({
        PRE_CHOMP  => 1,
        POST_CHOMP => 1,
    });

  INTERPOLATE
The INTERPOLATE flag can be set to allow variables to be embedded in plain text blocks.

    my $parser = Template::Parser->new({
        INTERPOLATE => 1,
    });

Variables should be prefixed by a "$" to identify them, using curly braces to explicitly scope the variable name where necessary.

    Hello ${name},

    The day today is ${day.today}.

  ANYCASE
The ANYCASE option can be set to allow directive keywords to be specified in any case.

    # with ANYCASE set to 1
    [% INCLUDE foobar %]    # OK
    [% include foobar %]    # OK
    [% include = 10   %]    # ERROR, 'include' is a reserved word

  GRAMMAR
The GRAMMAR configuration item can be used to specify an alternate grammar for the parser. This allows a modified or entirely new template language to be constructed and used by the Template Toolkit.

    use MyOrg::Template::Grammar;

    my $parser = Template::Parser->new({
        GRAMMAR = MyOrg::Template::Grammar->new();
    });

By default, an instance of the default Template::Grammar will be created and used automatically if a "GRAMMAR" item isn't specified.

  DEBUG
The DEBUG option can be used to enable various debugging features of the "Template::Parser" module.

    use Template::Constants qw( :debug );

    my $template = Template->new({
        DEBUG => DEBUG_PARSER | DEBUG_DIRS,
    });

AUTHOR
Andy Wardley <abw@wardley.org> <http://wardley.org/>

COPYRIGHT
Copyright (C) 1996-2022 Andy Wardley. All Rights Reserved.

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

The main parsing loop of the "Template::Parser" module was derived from a standalone parser generated by version 0.16 of the "Parse::Yapp" module. The following copyright notice appears in the "Parse::Yapp" documentation.

    The Parse::Yapp module and its related modules and shell
    scripts are copyright (c) 1998 Francois Desarmenien,
    France. All rights reserved.

    You may use and distribute them under the terms of either
    the GNU General Public License or the Artistic License, as
    specified in the Perl README file.

SEE ALSO
Template, Template::Grammar, Template::Directive