Catalyst::Component - Catalyst Component Base Class


    # lib/MyApp/Model/
    package MyApp::Model::Something;

    use base 'Catalyst::Component';

    __PACKAGE__->config( foo => 'bar' );

    sub test {
        my $self = shift;
        return $self->{foo};

    sub forward_to_me {
        my ( $self, $c ) = @_;
        $c->response->output( $self->{foo} );


    # Methods can be a request step
    $c->forward(qw/MyApp::Model::Something forward_to_me/);

    # Or just methods
    print $c->comp('MyApp::Model::Something')->test;

    print $c->comp('MyApp::Model::Something')->{foo};


This is the universal base class for Catalyst components (Model/View/Controller).

It provides you with a generic new() for instantiation through Catalyst's component loader with config() support and a process() method placeholder.


new($c, $arguments)

Called by COMPONENT to instantiate the component; should return an object to be stored in the application's component hash.


my $component_instance = $component->COMPONENT($app, $arguments);

If this method is present (as it is on all Catalyst::Component subclasses, it is called by Catalyst during setup_components with the application class as $c and any config entry on the application for this component (for example, in the case of MyApp::Controller::Foo this would be MyApp->config('Controller::Foo' => \%conf). The arguments are expected to be a hashref and are merged with the __PACKAGE__->config hashref before calling ->new to instantiate the component.

You can override it in your components to do custom instantiation, using something like this:

      my ($class, $app, $args) = @_;
      $args = $self->merge_config_hashes($self->config, $args);
      return $class->new($app, $args);



$c->config($key, $value, ...)

Accessor for this component's config hash. Config values can be set as key value pair, or you can specify a hashref. In either case the keys will be merged with any existing config settings. Each component in a Catalyst application has its own config hash.


This is the default method called on a Catalyst component in the dispatcher. For instance, Views implement this action to render the response body when you forward to them. The default is an abstract method.

$c->merge_config_hashes( $hashref, $hashref )

Merges two hashes together recursively, giving right-hand precedence. Alias for the method in Catalyst::Utils.



Catalyst components are normally initialized during server startup, either as a Class or a Instance. However, some components require information about the current request. To do so, they can implement an ACCEPT_CONTEXT method.

If this method is present, it is called during $c->comp/controller/model/view with the current $c and any additional args (e.g. $c->model('Foo', qw/bar baz/) would cause your MyApp::Model::Foo instance's ACCEPT_CONTEXT to be called with ($c, 'bar', 'baz')) and the return value of this method is returned to the calling code in the application rather than the component itself.


Catalyst, Catalyst::Model, Catalyst::View, Catalyst::Controller.


Catalyst Contributors, see


This library is free software. You can redistribute it and/or modify it under the same terms as Perl itself.