Catalyst::View::TT - Template View Class

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NAME

Catalyst::View::TT - Template View Class

SYNOPSIS

# use the helper to create View myapp_create.pl view TT TT

# configure in lib/MyApp.pm

    MyApp->config(
        name     => 'MyApp',
        root     => MyApp->path_to('root');,
        'View::TT' => {
            # any TT configurations items go here
            INCLUDE_PATH => [
              MyApp->path_to( 'root', 'src' ), 
              MyApp->path_to( 'root', 'lib' ), 
            ],
            PRE_PROCESS        => 'config/main',
            WRAPPER            => 'site/wrapper',
            TEMPLATE_EXTENSION => '.tt',

            # two optional config items
            CATALYST_VAR => 'Catalyst',
            TIMER        => 1,
        },
    );
         
# render view from lib/MyApp.pm or lib/MyApp::C::SomeController.pm
    
    sub message : Global {
        my ( $self, $c ) = @_;
        $c->stash->{template} = 'message.tt2';
        $c->stash->{message}  = 'Hello World!';
        $c->forward('MyApp::V::TT');
    }

# access variables from template

    The message is: [% message %].
    
    # example when CATALYST_VAR is set to 'Catalyst'
    Context is [% Catalyst %]          
    The base is [% Catalyst.req.base %] 
    The name is [% Catalyst.config.name %] 
    
    # example when CATALYST_VAR isn't set
    Context is [% c %]
    The base is [% base %]
    The name is [% name %]

DESCRIPTION

This is the Catalyst view class for the Template Toolkit. Your application should defined a view class which is a subclass of this module. The easiest way to achieve this is using the myapp_create.pl script (where myapp should be replaced with whatever your application is called). This script is created as part of the Catalyst setup.

    $ script/myapp_create.pl view TT TT

This creates a MyApp::V::TT.pm module in the lib directory (again, replacing MyApp with the name of your application) which looks something like this:

    package FooBar::V::TT;
    
    use strict;
     use base 'Catalyst::View::TT';

    __PACKAGE__->config->{DEBUG} = 'all';

Now you can modify your action handlers in the main application and/or controllers to forward to your view class. You might choose to do this in the end() method, for example, to automatically forward all actions to the TT view class.

    # In MyApp or MyApp::Controller::SomeController
    
    sub end : Private {
        my( $self, $c ) = @_;
        $c->forward('MyApp::V::TT');
    }

CONFIGURATION

There are a three different ways to configure your view class. The first way is to call the config() method in the view subclass. This happens when the module is first loaded.

    package MyApp::V::TT;
    
    use strict;
    use base 'Catalyst::View::TT';

    MyApp::V::TT->config({
        INCLUDE_PATH => [
            MyApp->path_to( 'root', 'templates', 'lib' ),
            MyApp->path_to( 'root', 'templates', 'src' ),
        ],
        PRE_PROCESS  => 'config/main',
        WRAPPER      => 'site/wrapper',
    });

The second way is to define a new() method in your view subclass. This performs the configuration when the view object is created, shortly after being loaded. Remember to delegate to the base class new() method (via $self->NEXT::new() in the example below) after performing any configuration.

    sub new {
        my $self = shift;
        $self->config({
            INCLUDE_PATH => [
                MyApp->path_to( 'root', 'templates', 'lib' ),
                MyApp->path_to( 'root', 'templates', 'src' ),
            ],
            PRE_PROCESS  => 'config/main',
            WRAPPER      => 'site/wrapper',
        });
        return $self->NEXT::new(@_);
    }
 
The final, and perhaps most direct way, is to define a class
item in your main application configuration, again by calling the
uniquitous C<config()> method.  The items in the class hash are
added to those already defined by the above two methods.  This happens
in the base class new() method (which is one reason why you must
remember to call it via C<NEXT> if you redefine the C<new()> method in a
subclass).

    package MyApp;
    
    use strict;
    use Catalyst;
    
    MyApp->config({
        name     => 'MyApp',
        root     => MyApp->path_to('root'),
        'V::TT' => {
            INCLUDE_PATH => [
                MyApp->path_to( 'root', 'templates', 'lib' ),
                MyApp->path_to( 'root', 'templates', 'src' ),
            ],
            PRE_PROCESS  => 'config/main',
            WRAPPER      => 'site/wrapper',
        },
    });

Note that any configuration items defined by one of the earlier methods will be overwritten by items of the same name provided by the latter methods.

DYNAMIC INCLUDE_PATH

Sometimes it is desirable to modify INCLUDE_PATH for your templates at run time.


Additional paths can be added to the start of INCLUDE_PATH via the stash as
follows:

    $c->stash->{additional_template_paths} =
        [$c->config->{root} . '/test_include_path'];

If you need to add paths to the end of INCLUDE_PATH, there is also an include_path() accessor available:

    push( @{ $c->view('TT')->include_path }, qw/path/ );

Note that if you use include_path() to add extra paths to INCLUDE_PATH, you MUST check for duplicate paths. Without such checking, the above code will add ``path'' to INCLUDE_PATH at every request, causing a memory leak.

A safer approach is to use include_path() to overwrite the array of paths rather than adding to it. This eliminates both the need to perform duplicate checking and the chance of a memory leak:

    @{ $c->view('TT')->include_path } = qw/path another_path/;

RENDERING VIEWS

The view plugin renders the template specified in the template item in the stash.

    sub message : Global {
        my ( $self, $c ) = @_;
        $c->stash->{template} = 'message.tt2';
        $c->forward('MyApp::V::TT');
    }

If a class item isn't defined, then it instead uses the current match, as returned by $c->match. In the above example, this would be message.

The items defined in the stash are passed to the Template Toolkit for use as template variables.

sub message : Global { sub default : Private { my ( $self, $c ) = @_; $c->stash->{template} = 'message.tt2'; $c->stash->{message} = 'Hello World!'; $c->forward('MyApp::V::TT'); }

A number of other template variables are also added:

    c      A reference to the context object, $c
    base   The URL base, from $c->req->base()
    name   The application name, from $c->config->{ name }

These can be accessed from the template in the usual way:

<message.tt2>:

    The message is: [% message %]
    The base is [% base %]
    The name is [% name %]

The output generated by the template is stored in $c->response->output.

TEMPLATE PROFILING

METHODS

new: The constructor for the TT view. Sets up the template provider, and reads the application config.
process: Renders the template specified in $c->stash->{template} or $c->action (the private name of the matched action. Template variables are set up from the contents of $c->stash, augmented with base set to $c->req->base, c to $c and name to $c->config->{name}. Alternately, the CATALYST_VAR configuration item can be defined to specify the name of a template variable through which the context reference ($c) can be accessed. In this case, the c, base and name variables are omitted. Output is stored in $c->response->output.
template_vars: Returns a list of keys/values to be used as the variables in the template.

HELPERS

The the Catalyst::Helper::View::TT manpage and the Catalyst::Helper::View::TTSite manpage helper modules are provided to create your view module. There are invoked by the myapp_create.pl script:

    $ script/myapp_create.pl view TT TT

    $ script/myapp_create.pl view TT TTSite

The the Catalyst::Helper::View::TT manpage module creates a basic TT view module. The the Catalyst::Helper::View::TTSite manpage module goes a little further. It also creates a default set of templates to get you started. It also configures the view module to locate the templates automatically.

AUTHORS

Sebastian Riedel, sri@cpan.org

Marcus Ramberg, mramberg@cpan.org

Jesse Sheidlower, jester@panix.com

Andy Wardley, abw@cpan.org

COPYRIGHT

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

Catalyst::View::TT - Template View Class