Linux Certif

Toute la documentation sur la certification Linux LPI

CGI::Application::Plugin::AnyTemplate::Driver::TemplateToolkit.3pm

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.

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, "<mag-perl@occamstoothbrush.com>"

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.