NAME

Template::Plugins - Plugin provider module

SYNOPSIS

    use Template::Plugins;
    
    $plugin_provider = Template::Plugins->new(\%options);
    
    ($plugin, $error) = $plugin_provider->fetch($name, @args);

DESCRIPTION

The "Template::Plugins" module defines a provider class which can be used to load and instantiate Template Toolkit plugin modules.

METHODS

new(\%params)

Constructor method which instantiates and returns a reference to a "Template::Plugins" object. A reference to a hash array of configuration items may be passed as a parameter. These are described below.

Note that the Template front-end module creates a "Template::Plugins" provider, passing all configuration items. Thus, the examples shown below in the form:

    $plugprov = Template::Plugins->new({
        PLUGIN_BASE => 'MyTemplate::Plugin',
        LOAD_PERL   => 1,
        ...
    });

can also be used via the Template module as:

    $ttengine = Template->new({
        PLUGIN_BASE => 'MyTemplate::Plugin',
        LOAD_PERL   => 1,
        ...
    });

as well as the more explicit form of:

    $plugprov = Template::Plugins->new({
        PLUGIN_BASE => 'MyTemplate::Plugin',
        LOAD_PERL   => 1,
        ...
    });
    
    $ttengine = Template->new({
        LOAD_PLUGINS => [ $plugprov ],
    });

fetch($name, @args)

Called to request that a plugin of a given name be provided. The relevant module is first loaded (if necessary) and the load() class method called to return the factory class name (usually the same package name) or a factory object (a prototype). The new() method is then called as a class or object method against the factory, passing all remaining parameters.

Returns a reference to a new plugin object or "($error, STATUS_ERROR)" on error. May also return "(undef, STATUS_DECLINED)" to decline to serve the request. If "TOLERANT" is set then all errors will be returned as declines.

CONFIGURATION OPTIONS

The following list summarises the configuration options that can be provided to the "Template::Plugins" new() constructor. Please consult Template::Manual::Config for further details and examples of each configuration option in use.

PLUGINS

The PLUGINS option can be used to provide a reference to a hash array that maps plugin names to Perl module names.

    my $plugins = Template::Plugins->new({
        PLUGINS => {
            cgi => 'MyOrg::Template::Plugin::CGI',
            foo => 'MyOrg::Template::Plugin::Foo',
            bar => 'MyOrg::Template::Plugin::Bar',
        },  
    });

PLUGIN_BASE

If a plugin is not defined in the PLUGINS hash then the PLUGIN_BASE is used to attempt to construct a correct Perl module name which can be successfully loaded.

    # single value PLUGIN_BASE
    my $plugins = Template::Plugins->new({
        PLUGIN_BASE => 'MyOrg::Template::Plugin',
    });

    # multiple value PLUGIN_BASE
    my $plugins = Template::Plugins->new({
        PLUGIN_BASE => [   'MyOrg::Template::Plugin',
                           'YourOrg::Template::Plugin'  ],
    });

LOAD_PERL

The LOAD_PERL option can be set to allow you to load regular Perl modules (i.e. those that don't reside in the "Template::Plugin" or another user-defined namespace) as plugins.

If a plugin cannot be loaded using the PLUGINS or PLUGIN_BASE approaches then, if the LOAD_PERL is set, the provider will make a final attempt to load the module without prepending any prefix to the module path.

Unlike regular plugins, modules loaded using LOAD_PERL do not receive a Template::Context reference as the first argument to the "new()" constructor method.

TOLERANT

The TOLERANT flag can be set to indicate that the "Template::Plugins" module should ignore any errors encountered while loading a plugin and instead return "STATUS_DECLINED".

DEBUG

The DEBUG option can be used to enable debugging messages for the "Template::Plugins" module by setting it to include the "DEBUG_PLUGINS" value.

    use Template::Constants qw( :debug );
    
    my $template = Template->new({
        DEBUG => DEBUG_FILTERS | DEBUG_PLUGINS,
    });

TEMPLATE TOOLKIT PLUGINS

Please see Template::Manual::Plugins For a complete list of all the plugin modules distributed with the Template Toolkit.

AUTHOR

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

COPYRIGHT

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