=head1 NAME Catalyst::Manual::CatalystAndMoose - How Catalyst 5.8+ and Moose relate =head1 DESCRIPTION Since version 5.8 the core of Catalyst is based on L. Although the developers went through great lengths to allow for a seamless transition, there are still a few things to keep in mind when trying to exploit the power of L in your Catalyst application. This document provides you with a short overview of common caveats and best practices to use L-based classes within Catalyst. =head1 THE CONTEXT CLASS A Moose-ified version of the context class should look like this: package MyApp; use Moose; use Catalyst; $app->config( name => 'MyApp' ); $app->setup( # your roles and plugins ); # method modifiers must be created after setup because otherwise they will # conflict with plugin overrides after 'finalize' => sub{ my $c = shift; $c->log->info( 'done!' ); } You should also be aware, that roles in C<< $c->setup >> are applied after the last plugin with all the benefits of using a single C<< with() >> statement in an ordinary L class and that your class is automatically made immutable for you after the call to setup (method modifiers in your class will work, though). CAVEAT: using roles in C<< $c->setup >> was implemented in Catalyst version 5.80004. In prior versions you might get away with after 'setup_plugins' => sub{ with( # your roles )}; $app->setup( # your plugins ); but this is discouraged and you should upgrade to 5.80004 anyway, because it fixes a few important regression against 5.71 [Q: COULD THIS BE USED TO RESOLVE CONFLICTS IN ROLES?]. =head2 ACCESSORS Most of the request specific attributes like C<$c->stash>, C<$c->request> and C<$c->response> have been converted to L attributes but without type constraints, attribute helpers or builder methods. This ensures that Catalyst 5.8 is fully backwards compatible to applications using the published API of Catalyst 5.7 but slightly limits the gains that could be had by wielding the full power of L attributes. Most of the accessors to information gathered during compile time is managed by C, which is a L-aware version of L but not compatible with L. =head2 ROLES AND METHOD MODIFIERS Since the release of Catalyst version 5.8 the only reason for creating a Catalyst extension as a plugin is to provide backward compatibility to applications still using version 5.7 but even then you should consider building your plugin using L and take advantage of L instead of overriding methods to alter Catalyst's request lifecycle behavior. If backward compatibility is of no concern to you, you could as easily rewrite your plugins as roles and enjoy all the benefits of automatic method re-dispatching of C<< before >> and C<< after >> method modifiers, naming conflict detecting and generally cleaner code. Plugins and roles should never use after 'setup' => sub { ... } # wrong but rely on after 'setup_finalize' => sub { ... } # this will work to run their own setup code if needed. If they need to influence the setup process itself, they can modify C<< setup_dispatcher() >>, C<< setup_engine()>>, C<< setup_stats() >>, C<< setup_components() >> and C<< setup_actions() >>, but this should be done with due consideration and as late as possible. =head1 CONTROLLERS To activate Catalyst's action attributes, Moose-ified controller classes need to extend L at compile time before the actions themselves are declared: package Catalyst::Controller::Root; use Moose; BEGIN{ extends 'Catalyst::Controller'; with( # your controller roles ); } [MORE TO BE DONE!]