[%# # IMPORTANT NOTE # This documentation is generated automatically from source # templates. Any changes you make here may be lost. # # The 'docsrc' documentation source bundle is available for download # from http://www.template-toolkit.org/docs.html and contains all # the source templates, XML files, scripts, etc., from which the # documentation for the Template Toolkit is built. -%] [% META book = 'Modules' page = 'Template' %] [% WRAPPER toc; PROCESS tocitem title ="SYNOPSIS " subs = []; PROCESS tocitem title ="DESCRIPTION" subs = []; PROCESS tocitem title ="METHODS" subs = [ "new(\\%config)", "process(\$template, \\%vars, \$output, %options)", "error()", "service()", "context()" ]; PROCESS tocitem title ="CONFIGURATION SUMMARY" subs = [ "Template Style and Parsing Options", "Template Files and Blocks", "Template Variables", "Runtime Processing Options", "Caching and Compiling Options", "Plugins and Filters", "Compatibility, Customisation and Extension" ]; PROCESS tocitem title ="DIRECTIVE SUMMARY" subs = []; PROCESS tocitem title ="AUTHOR" subs = []; PROCESS tocitem title ="VERSION" subs = []; PROCESS tocitem title ="COPYRIGHT" subs = []; END %] [% WRAPPER section title="SYNOPSIS " -%]
  use Template;
  # some useful options (see below for full list)
  my $config = {
      INCLUDE_PATH => '/search/path',  # or list ref
      INTERPOLATE  => 1,               # expand "$var" in plain text
      POST_CHOMP   => 1,               # cleanup whitespace 
      PRE_PROCESS  => 'header',        # prefix each template
      EVAL_PERL    => 1,               # evaluate Perl code blocks
  # create Template object
  my $template = Template->new($config);
  # define template variables for replacement
  my $vars = {
      var1  => $value,
      var2  => \%hash,
      var3  => \@list,
      var4  => \&code,
      var5  => $object,
  # specify input filename, or file handle, text reference, etc.
  my $input = 'myfile.html';
  # process input template, substituting variables
  $template->process($input, $vars)
      || die $template->error();
[%- END %] [% WRAPPER section title="DESCRIPTION" -%]

This documentation describes the Template module which is the direct Perl interface into the Template Toolkit. It covers the use of the module and gives a brief summary of configuration options and template directives. Please see [% ttlink('Template::Manual') -%] for the complete reference manual which goes into much greater depth about the features and use of the Template Toolkit. The [% ttlink('Template::Tutorial') -%] is also available as an introductory guide to using the Template Toolkit.

[%- END %] [% WRAPPER section title="METHODS" -%][% WRAPPER subsection title = "new(\\%config)" -%]

The new() constructor method (implemented by the Template::Base base class) instantiates a new Template object. A reference to a hash array of configuration items may be passed as a parameter.

    my $tt = Template->new({
    	INCLUDE_PATH => '/usr/local/templates',
	    EVAL_PERL    => 1,
    }) || die $Template::ERROR, "\n";

A reference to a new Template object is returned, or undef on error. In the latter case, the error message can be retrieved by calling error() as a class method (e.g. 'Template->error()') or by examining the $ERROR package variable directly (e.g. '$Template::ERROR').

    my $tt = Template->new(\%config)
        || die Template->error(), "\n";
    my $tt = Template->new(\%config)
        || die $Template::ERROR, "\n";

For convenience, configuration items may also be specified as a list of items instead of a hash array reference. These are automatically folded into a hash array by the constructor.

    my $tt = Template->new(INCLUDE_PATH => '/tmp', POST_CHOMP => 1)
	|| die $Template::ERROR, "\n";
[%- END %] [% WRAPPER subsection title = "process(\$template, \\%vars, \$output, %options)" -%]

The process() method is called to process a template. The first parameter indicates the input template as one of: a filename relative to INCLUDE_PATH, if defined; a reference to a text string containing the template text; or a file handle reference (e.g. IO::Handle or sub-class) or GLOB (e.g. \*STDIN), from which the template can be read. A reference to a hash array may be passed as the second parameter, containing definitions of template variables.

    $text = "[% tt_start_tag %] INCLUDE header [% tt_end_tag %]\nHello world!\n[% tt_start_tag %] INCLUDE footer [% tt_end_tag %]";
    # filename
        || die $tt->error(), "\n";
    # text reference
        || die $tt->error(), "\n";
    # GLOB
        || die $tt->error(), "\n";
    [% tt_start_tag %] INCLUDE header [% tt_end_tag %]
    This is a template defined in the __END__ section which is 
    accessible via the DATA "file handle".
    [% tt_start_tag %] INCLUDE footer [% tt_end_tag %]

By default, the processed template output is printed to STDOUT. The process() method then returns 1 to indicate success. A third parameter may be passed to the process() method to specify a different output location. This value may be one of: a plain string indicating a filename which will be opened (relative to OUTPUT_PATH, if defined) and the output written to; a file GLOB opened ready for output; a reference to a scalar (e.g. a text string) to which output/error is appended; a reference to a subroutine which is called, passing the output as a parameter; or any object reference which implements a 'print' method (e.g. IO::Handle, Apache::Request, etc.) which will be called, passing the generated output as a parameter.


    # output filename
    $tt->process('welcome.tt2', $vars, 'welcome.html')
        || die $tt->error(), "\n";
    # reference to output subroutine
    sub myout {
    	my $output = shift;
    $tt->process('welcome.tt2', $vars, \&myout)
        || die $tt->error(), "\n";
    # reference to output text string
    my $output = '';
    $tt->process('welcome.tt2', $vars, \$output)
        || die $tt->error(), "\n";
    print "output: $output\n";

In an Apache/mod_perl handler:

    sub handler {
	my $req = shift;
	# direct output to Apache::Request via $req->print($output)
	$tt->process($file, $vars, $req) || do {
	    return SERVER_ERROR;
	return OK;

After the optional third output argument can come an optional reference to a hash or a list of (name, value) pairs providing further options for the output. The only option currently supported is "binmode" which, when set to any true value will ensure that files created (but not any existing file handles passed) will be set to binary mode.

    # either: hash reference of options
    $tt->process($infile, $vars, $outfile, { binmode => 1 })
        || die $tt->error(), "\n";
    # or: list of name, value pairs
    $tt->process($infile, $vars, $outfile, binmode => 1)
        || die $tt->error(), "\n";

Alternately, the binmode argument can specify a particular IO layer such as ":utf8".

    $tt->process($infile, $vars, $outfile, binmode => ':utf8')
        || die $tt->error(), "\n";

The OUTPUT configuration item can be used to specify a default output location other than \*STDOUT. The OUTPUT_PATH specifies a directory which should be prefixed to all output locations specified as filenames.

    my $tt = Template->new({
    	OUTPUT      => sub { ... },       # default
	    OUTPUT_PATH => '/tmp',
    }) || die Template->error(), "\n";
    # use default OUTPUT (sub is called)
    $tt->process('welcome.tt2', $vars)
        || die $tt->error(), "\n";
    # write file to '/tmp/welcome.html'
    $tt->process('welcome.tt2', $vars, 'welcome.html')
        || die $tt->error(), "\n";

The process() method returns 1 on success or undef on error. The error message generated in the latter case can be retrieved by calling the error() method. See also [% ttlink('CONFIGURATION SUMMARY') -%] which describes how error handling may be further customised.

[%- END %] [% WRAPPER subsection title = "error()" -%]

When called as a class method, it returns the value of the $ERROR package variable. Thus, the following are equivalent.

    my $tt = Template->new()
        || die Template->error(), "\n";
    my $tt = Template->new()
        || die $Template::ERROR, "\n";

When called as an object method, it returns the value of the internal _ERROR variable, as set by an error condition in a previous call to process().

        || die $tt->error(), "\n";

Errors are represented in the Template Toolkit by objects of the Template::Exception class. If the process() method returns a false value then the error() method can be called to return an object of this class. The type() and info() methods can called on the object to retrieve the error type and information string, respectively. The as_string() method can be called to return a string of the form "$type - $info". This method is also overloaded onto the stringification operator allowing the object reference itself to be printed to return the formatted error string.

    $tt->process('somefile') || do {
    	my $error = $tt->error();
	    print "error type: ", $error->type(), "\n";
    	print "error info: ", $error->info(), "\n";
	    print $error, "\n";
[%- END %] [% WRAPPER subsection title = "service()" -%]

The Template module delegates most of the effort of processing templates to an underlying Template::Service object. This method returns a reference to that object.

[%- END %] [% WRAPPER subsection title = "context()" -%]

The Template::Service module uses a core Template::Context object for runtime processing of templates. This method returns a reference to that object and is equivalent to $template->service->context();

[%- END %] [%- END %] [% WRAPPER section title="CONFIGURATION SUMMARY" -%]

The following list gives a short summary of each Template Toolkit configuration option. See [% ttlink('Template::Manual::Config') -%] for full details.

[% WRAPPER subsection title = "Template Style and Parsing Options" -%] [%- END %] [% WRAPPER subsection title = "Template Files and Blocks" -%] [%- END %] [% WRAPPER subsection title = "Template Variables" -%] [%- END %] [% WRAPPER subsection title = "Runtime Processing Options" -%] [%- END %] [% WRAPPER subsection title = "Caching and Compiling Options" -%] [%- END %] [% WRAPPER subsection title = "Plugins and Filters" -%] [%- END %] [% WRAPPER subsection title = "Compatibility, Customisation and Extension" -%] [%- END %] [%- END %] [% WRAPPER section title="DIRECTIVE SUMMARY" -%]

The following list gives a short summary of each Template Toolkit directive. See [% ttlink('Template::Manual::Directives') -%] for full details.

[%- END %] [% WRAPPER section title="AUTHOR" -%]

Andy Wardley <abw@wardley.org>

[% ttlink('http://wardley.org/', 'http://wardley.org/') -%]

[%- END %] [% WRAPPER section title="VERSION" -%]

Template Toolkit version 2.19, released on 27 April 2007.

[%- END %] [% WRAPPER section title="COPYRIGHT" -%]
  Copyright (C) 1996-2007 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.

[%- END %]