Catalyst::Manual::ActiUser3Contributed Perl DocumeCatalyst::Manual::Actions(3)NAMECatalyst::Manual::Actions - Catalyst Reusable Actions
DESCRIPTION
This section of the manual describes the reusable action system in
Catalyst, how such actions work, descriptions of some existing ones,
and how to write your own. Reusable actions are attributes on Catalyst
methods that allow you to decorate your method with functions running
before or after the method call. This can be used to implement
commonly used action patterns, while still leaving you full freedom to
customize them.
USING ACTIONS
This is pretty simple. Actions work just like the normal dispatch
attributes you are used to, like Local or Private:
sub Hello :Local :ActionClass('SayBefore') {
$c->res->output( 'Hello '.$c->stash->{what} );
}
In this example, we expect the SayBefore action to magically populate
stash with something relevant before "Hello" is run. In the next
section we'll show you how to implement it. If you want it in a
namespace other than Catalyst::Action you can prefix the action name
with a '+', for instance '+Foo::SayBefore', or if you just want it
under your application namespace instead, use MyAction, like
MyAction('SayBefore').
WRITING YOUR OWN ACTIONS
Implementing the action itself is almost as easy. Just use
Catalyst::Action as a base class and decorate the "execute" call in the
Action class:
package Catalyst::Action::MyAction;
use Moose;
use namespace::autoclean;
extends 'Catalyst::Action';
before 'execute' => sub {
my ( $self, $controller, $c, $test ) = @_;
$c->stash->{what} = 'world';
};
after 'execute' => sub {
my ( $self, $controller, $c, $test ) = @_;
$c->stash->{foo} = 'bar';
};
__PACKAGE__->meta->make_immutable;
Pretty simple, huh?
ACTION ROLES
You can only have one action class per action, which can be somewhat
inflexible.
The solution to this is to use Catalyst::Controller::ActionRole, which
would make the example above look like this:
package Catalyst::ActionRole::MyActionRole;
use Moose::Role;
before 'execute' => sub {
my ( $self, $controller, $c, $test ) = @_;
$c->stash->{what} = 'world';
};
after 'execute' => sub {
my ( $self, $controller, $c, $test ) = @_;
$c->stash->{foo} = 'bar';
};
1;
and this would be used in a controller like this:
package MyApp::Controller::Foo;
use Moose;
use namespace::autoclean;
BEGIN { extends 'Catalyst::Controller::ActionRole'; }
sub foo : Does('MyActionRole') {
my ($self, $c) = @_;
}
1;
EXAMPLE ACTIONS
Catalyst::Action::RenderView
This is meant to decorate end actions. It's similar in operation to
Catalyst::Plugin::DefaultEnd, but allows you to decide on an action
level rather than on an application level where it should be run.
Catalyst::Action::REST
Provides additional syntax for dispatching based upon the HTTP method
of the request.
EXAMPLE ACTIONROLES
Catalyst::ActionRole::ACL
Provides ACLs for role membership by decorating your actions.
AUTHORS
Catalyst Contributors, see Catalyst.pm
COPYRIGHT
This library is free software. You can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.2 2011-02-16 Catalyst::Manual::Actions(3)