CGI::Application::Plugin::AnyTemplate::Base - Base class for templates

METHODS FOR DEVELOPERS

AUTHOR
BUGS
SEE ALSO
COPYRIGHT & LICENSE

NAME

CGI::Application::Plugin::AnyTemplate::Base - Base class for templates

DESCRIPTION

This documentation is mainly for developers who want to write additional Template drivers. For how to use the system, see the docs for the CGI::Application::Plugin::AnyTemplate manpage

METHODS

param

The param method gets and sets values within the template.

    my $template = $self->template->load;

    my @param_names = $template->param();

    my $value = $template->param('name');

    $template->param('name' => 'value');
    $template->param(
        'name1' => 'value1',
        'name2' => 'value2'
    );

It is designed to behave similarly to the param method in other modules like CGI and HTML::Template.

get_param_hash

Returns the template variables as a hash of names and values.

    my %params     = $template->get_param_hash;

In a scalar context, returns a reference to the hash used internally to contain the values:

    my $params_ref = $template->get_param_hash;

clear_params

Clears the values stored in the template:

    $template->param(
        'name1' => 'value1',
        'name1' => 'value2'
    );
    $template->clear_params;
    $template->param(
        'name_foo' => 'value_bar',
    );

    # params are now:
        'name_foo' => 'value_bar',

output

Returns the template with all the values filled in.

    return $template->output();

You can also supply names and values to the template at this stage:

    return $template->output('name' => 'value', 'name2' => 'value2');

Before the template output is generated, the template_pre_process hook is called. Any callbacks that you register to this hook will be called before each template is processed. Register a template_pre_process callback as follows:

    $self->add_callback('template_pre_process', \&my_tmpl_pre_process);

Pre-process callbacks will be passed a reference to the $template object, and can can modify the parameters passed into the template by using the param method:

    sub my_tmpl_pre_process {
        my ($self, $template) = @_;

        # Change the internal template parameters by reference
        my $params = $template->get_param_hash;

        foreach my $key (keys %$params) {
            $params{$key} = to_piglatin($params{$key});
        }

        # Can also set values using the param method
        $template->param('foo', 'bar');

After the template output is generated, the template_post_process hook is called. You can register a template_post_process callback as follows:

    $self->add_callback('template_post_process', \&my_tmpl_post_process);

Any callbacks that you register to this hook will be called after each template is processed, and will be passed both a reference to the template object and a reference to the output generated by the template. This allows you to modify the output of the template:

    sub my_tmpl_post_process {
        my ($self, $template, $output_ref) = @_;

        $$output_ref =~ s/foo/bar/;
    }

When you call the output method, any components embedded in the template are run. See EMBEDDED COMPONENTS, below.

filename

If the template was loaded from a file, the filename method returns the template filename.

string_ref

If the template was loaded from a string, the string_ref method returns a reference to the string.

object

Returns a reference to the underlying template driver, e.g. the HTML::Template object or the Template::Toolkit object.

DOCS FOR TEMPLATE MODULE DEVELOPERS

The following documentation is of interest primarly for developers who wish to add support for a new type of Template system.

METHODS FOR DEVELOPERS

initialize

This method is called by the controller at load to create the driver-specific subclass of CGI::Application::Plugin::AnyTemplate

This is a virtual method and must be defined in the subclass.

The following paramters are passed to the driver and available as keys of the driver's $self object:

     'driver_config' => ...    # hashref of driver-specific config
     'native_config' => ...    # hashref of native template system specific config
     'include_paths' => ...    # listref of template include paths
     'filename'      => ...    # template filename
     'webapp'        => ...    # reference to the current CGI::Application $self

driver_config_keys

When it creates the driver object, CGI::Application::Plugin::AnyTemplate has to separate the driver_config from the native_config.

driver_config_params should return a list of parameters that are specific to the driver_config and not the native template system config.

For instance, the user can specify

    $self->template->config(
        HTMLTemplate => {
              embed_tag_name    => 'embed',
              global_vars       => 1,
              die_on_bad_params => 0,
              cache             => 1
        },
    );

The parameters global_vars, die_on_bad_params, and cache are all specific to the HTML::Template manpage. These are considered native parameters.

But embed_tag_name configures the CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplate subclass. This is considered a driver parameter.

Therefore 'embed_tag_name' should be included in the list of params returned by driver_config_params.

Example driver_config_params:

    sub driver_config_keys {
        'template_extension',
        'embed_tag_name'
    }

default_driver_config

Should return a hash of default values for driver_config_params.

For instance:

    sub default_driver_config {
        {
            template_extension => '.foo',
            embed_tag_name     => 'embed',
        };
    }

render_template

This method must be overriden in a subclass. It has the responsibility of filling the template in $self->filename with the values in $self->param via the appropriate template system, and returning the output as either a string or a reference to a string.

It also must manage embedding nested components.

AUTHOR

Michael Graham, <mag-perl@occamstoothbrush.com>

BUGS

Please report any bugs or feature requests to bug-cgi-application-plugin-anytemplate@rt.cpan.org, or through the web interface at http://rt.cpan.org. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

COPYRIGHT & LICENSE

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

CGI::Application::Plugin::AnyTemplate::Base - Base class for templates