NAME

       Catalyst::ActionRole::ACL - User role-based authorization action class

SYNOPSIS

        package MyApp::Controller::Foo;
        use Moose;
        use namespace::autoclean;

        BEGIN { extends 'Catalyst::Controller' }

        sub foo
        :Local
        :Does(ACL)
        :RequiresRole(admin)
        :ACLDetachTo(denied)
        {
            my ($self, $c) = @_;
            ...
        }

        sub denied :Private {
            my ($self, $c) = @_;

            $c->res->status('403');
            $c->res->body('Denied!');
        }

DESCRIPTION

       Provides a reusable action role for user role-based authorization.  ACLs are applied via
       the assignment of attributes to application action subroutines.

REQUIRED ATTRIBUTES

       Failure to include the following required attributes will result in an exception when the
       ACL::Role action's constructor is called.

   ACLDetachTo
       The name of an action to which the request should be detached if it is determined that
       ACLs are not satisfied for this user and the resource he is attempting to access.

   RequiresRole and AllowedRole
       The action must include at least one of these attributes, otherwise the Role::ACL
       constructor will throw an exception.

Processing of ACLs

       One or more roles may be associated with an action.

       User roles are fetched via the invocation of the context "user" object's "roles" method.

       Roles specified with the RequiresRole attribute are checked before roles specified with
       the AllowedRole attribute.

       The mandatory ACLDetachTo attribute specifies the name of the action to which execution
       will detach on access violation.

       ACLs may be applied to chained actions so that different roles are required or allowed for
       each link in the chain (or no roles at all).

       ACLDetachTo allows us to short-circuit traversal of an action chain as soon as access is
       denied to one of the actions in the chain by its ACL.

   Examples
        # this is an invalid action
        sub broken
        :Local
        :Does(ACL)
        {
            my ($self, $c) = @_;
            ...
        }

        This action will cause an exception because it's missing the ACLDetachTo attribute
        and has neither a RequiresRole nor an AllowedRole attribute. A Role::ACL action
        must include at least one RequiresRole or AllowedRole attribute.

        sub foo
        :Local
        :Does(ACL)
        :RequiresRole(admin)
        :ACLDetachTo(denied)
        {
            my ($self, $c) = @_;
            ...
        }

       This action may only be executed by users with the 'admin' role.

        sub bar :Local
        :Does(ACL)
        :RequiresRole(admin)
        :AllowedRole(editor)
        :AllowedRole(writer)
        :ACLDetachTo(denied)
        {
            my ($self, $c) = @_;
            ...
        }

       This action requires that the user has the 'admin' role and either the 'editor' or
       'writer' role (or both).

        sub easy :Local
        :Does(ACL)
        :AllowedRole(admin)
        :AllowedRole(user)
        :ACLDetachTo(denied)
        {
            my ($self, $c) = @_;
            ...
        }

       Any user with either the 'admin' or 'user' role may execute this action.

WRAPPED METHODS

   "BUILD( $args )"
       Throws an exception if parameters are missing or invalid.

   "execute( $controller, $c )"
       Overrides &Catalyst::Action::execute.

       In order for delegation to occur, the context 'user' object must exist (authenticated
       user) and the "can_visit" method must return a true value.

       See Catalyst::Action

   "can_visit( $c )"
       Return true if the authenticated user can visit this action.

       This method is useful for determining in advance if a user can execute a given action.

AUTHOR

       David P.C. Wollmann <converter42@gmail.com>

CONTRIBUTORS

       Converted from an action class to an action role by Tomas Doran (t0m)

BUGS

       This is new code. Find the bugs and report them, please.

COPYRIGHT & LICENSE

       Copyright 2009 by David P.C. Wollmann

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