/ 
CGI-Application-Plugin-AnyTemplate-0.18
River stage one • 2 direct dependents • 2 total dependents
/ CGI::Application::Plugin::AnyTemplate::Driver::TemplateToolkit

NAME

CGI::Application::Plugin::AnyTemplate::Driver::TemplateToolkit - Template::Toolkit plugin to AnyTemplate

DESCRIPTION

This is a driver for CGI::Application::Plugin::AnyTemplate, which provides the implementation details specific to rendering templates via the Template::Toolkit templating system.

All AnyTemplate drivers are designed to be used the same way. For general usage instructions, see the documentation of CGI::Application::Plugin::AnyTemplate.

EMBEDDED COMPONENT SYNTAX (Template::Toolkit)

The Template::Toolkit syntax for embedding components is:

[% CGIAPP.embed("some_run_mode", param1, param2, 'literal string3') %]

This can be overridden by the following configuration variables:

embed_tag_name       # default 'CGIAPP'

For instance by setting the following values in your configuration file:

embed_tag_name       'MYAPP'

Then the embedded component tag will look like:

[% MYAPP.embed("some_run_mode") %]

TT OBJECT CACHING (singleton support)

Introduction

In a persistent environment, rather than creating a Template::Toolkit object each time you fill a template, it is much more efficient to load a single Template::Toolkit object and use this object to render all of your templates.

However, in a persistent environment, you may have several different applications running, and they all might need to set different Template::Toolkit options (such as POST_CHOMP, etc.).

By default, when the TemplateToolkit driver creates a Template::Toolkit object, it caches it. From that point on, whenever the same application needs a Template::Toolkit object, the driver uses the cached object rather than creating a new one.

Multiple Applications in a Shared Persistent Environment

An attempt is made to prevent different applications from sharing the same TT object.

Internally, the TT objects are stored in a private hash keyed by the web application's class name.

You can explicitly specify the class name when you call config:

$self->template->config(
    type          => 'TemplateToolkit',
    TemplateToolkit => {
        storage_class => 'My::Project',
    },
);

If you don't specify the class name, then the package containing the subroutine that called config is used. For instance:

package My::Project;
sub setup {
    my $self = shift;
    $self->template->config(                 # My::Project is used to store
        type          => 'TemplateToolkit',  # cached TT object
    );
}

A typical CGI::Application module hierarchy looks like this:

CGI::Application
    My::Project
        My::Webapp

In this hierarchy, it makes sense to store the cached TT object in My::Project. To make this happen, either call $self->template->config from within My::Project, or explicitly name the storage_class when you call $self->template->config.

Disabling TT Object Caching

You can disable Template::Toolkit object caching entirely by providing a false value to the object_caching driver config parameter:

$self->template->config(
    type          => 'TemplateToolkit',
    TemplateToolkit => {
        object_caching => 0,
    },
);

TT Object Caching and Include Paths

The include_paths driver config parameter is not cached; it is set every time you call $self->template->load. So you can safely used cached TT objects even if the applications sharing the TT object need different include_paths.

CONFIGURATION

The CGI::Application::Plugin::AnyTemplate::Driver::TemplateToolkit driver accepts the following config parameters:

embed_tag_name

The name of the tag used for embedding components. Defaults to CGIAPP.

template_extension

If auto_add_template_extension is true, then CGI::Application::Plugin::AnyTemplate will append the value of template_extension to filename. By default the template_extension is .xhtml.

emulate_associate_query

This feature is now deprecated and will be removed in a future release.

If this config parameter is true, then CGI::Application::Plugin::AnyTemplate::Driver::TemplateToolkit will copy all of the webapp's query params into the template.

This is similar to what would happen if you used HTML::Template's associate feature with the webapp's query object:

my $driver = HTML::Template->new(
    associate => $self->query,
);

By default emulate_associate_query is false.

object_caching

Whether or not to cache the Template::Toolkit object in a persistent environment

By default, object_caching is enabled.

See "TT OBJECT CACHING (singleton support)", above.

storage_class

What class to use as the storage key when object caching is enabled.

By default, storage_class defaults to the package containing the subroutine that called $self->template->config.

See "TT OBJECT CACHING (singleton support)", above.

All other configuration parameters are passed on unchanged to Template::Toolkit.

CONFIGURING UTF-8 TEMPLATES

AnyTemplate does NOT support Template::Toolkit's binmode option at runtime:

# not possible with AnyTemplate
$tt->process($infile, $vars, $outfile, { binmode => 1 })
    || die $tt->error(), "\n";

# not possible with AnyTemplate
$tt->process($infile, $vars, $outfile, binmode => 1)
    || die $tt->error(), "\n";

# not possible with AnyTemplate
$tt->process($infile, $vars, $outfile, binmode => ':utf8')
    || die $tt->error(), "\n";

Instead, use the ENCODING option in the initial config:

$self->template->config(
    default_type => 'TemplateToolkit',
    TemplateToolkit => { 
        ENCODING => 'UTF-8' 
    }
);

If you have a mix of encodings in your templates, use a separate AnyTemplate configuration for each encoding:

$self->template('ascii')->config(
    default_type => 'TemplateToolkit',
);
$self->template('utf-8')->config(
    default_type => 'TemplateToolkit',
    TemplateToolkit => { 
        ENCODING => 'UTF-8' 
    }
);

required_modules

The required_modules function returns the modules required for this driver to operate. In this case: Template.

DRIVER METHODS

initialize

Initializes the TemplateToolkit driver. See the docs for CGI::Application::Plugin::AnyTemplate::Base for details.

render_template

Fills the Template::Toolkit object with $self->param

If the param emulate_associate_query is true, then set params for each of $self->{'webapp'}->query, mimicking HTML::Template's associate mechanism.

Also set up a CGI::Application::Plugin::AnyTemplate::ComponentHandler object so that the CGIAPP.embed callback will work.

Returns the output of the filled template as a string reference.

See the docs for CGI::Application::Plugin::AnyTemplate::Base for details.

SEE ALSO

CGI::Application::Plugin::AnyTemplate
CGI::Application::Plugin::AnyTemplate::Base
CGI::Application::Plugin::AnyTemplate::ComponentHandler
CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplate
CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplateExpr
CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplatePluggable
CGI::Application::Plugin::AnyTemplate::Driver::Petal

CGI::Application

Template::Toolkit
HTML::Template

HTML::Template::Pluggable
HTML::Template::Plugin::Dot

Petal

Exporter::Renaming

CGI::Application::Plugin::TT

ACKNOWLEDGEMENTS

Thanks to Cees Hek for discussing the issues of caching in a persistent environment. And also for his excellent CGI::Application::Plugin::TT module, from which I stole ideas and some code: especially the bit about how to change the include path in a TT object after you've initialized it.

AUTHOR

Michael Graham, <mgraham@cpan.org>

COPYRIGHT & LICENSE

Copyright 2005 Michael Graham, All Rights Reserved.

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