1 package Catalyst::Component;
5 use MooseX::Adopt::Class::Accessor::Fast;
10 with 'MooseX::Emulate::Class::Accessor::Fast';
11 with 'Catalyst::ClassData';
16 Catalyst::Component - Catalyst Component Base Class
20 # lib/MyApp/Model/Something.pm
21 package MyApp::Model::Something;
23 use base 'Catalyst::Component';
25 __PACKAGE__->config( foo => 'bar' );
33 my ( $self, $c ) = @_;
34 $c->response->output( $self->{foo} );
39 # Methods can be a request step
40 $c->forward(qw/MyApp::Model::Something forward_to_me/);
43 print $c->comp('MyApp::Model::Something')->test;
45 print $c->comp('MyApp::Model::Something')->{foo};
49 This is the universal base class for Catalyst components
50 (Model/View/Controller).
52 It provides you with a generic new() for instantiation through Catalyst's
53 component loader with config() support and a process() method placeholder.
57 __PACKAGE__->mk_classdata('_plugins');
60 my ( $orig, $self) = @_;
62 # Temporary fix, some components does not pass context to constructor
63 my $arguments = ( ref( $_[-1] ) eq 'HASH' ) ? $_[-1] : {};
65 my $args = $self->merge_config_hashes( $self->config, $arguments );
66 $self->$orig( $args );
72 my ( $self, $c ) = @_;
74 # Temporary fix, some components does not pass context to constructor
75 my $arguments = ( ref( $_[-1] ) eq 'HASH' ) ? $_[-1] : {};
76 if( my $next = $self->next::can ){
77 my $class = blessed $self || $self;
78 my ($next_package) = Class::MOP::get_code_info($next);
79 warn "There is a COMPONENT method resolving after Catalyst::Component in ${next_package}. This behavior is deprecated and will stop working in future releases.";
80 return $next->($self, $arguments);
82 return $self->new($c, $arguments);
87 my $class = blessed $self || $self;
90 my $meta = $class->meta;
91 if( $meta->has_package_symbol('$config') ){
92 $config = ${ $meta->get_package_symbol('$config') };
94 foreach my $super ( $meta->linearized_isa ) {
95 my $super_meta = Moose::Meta::Class->initialize($super);
96 if( $super_meta->has_package_symbol('$config') ){
97 $config = ${ $super_meta->get_package_symbol('$config') };
98 unless( @_ ){ #don't copy and write it twice
99 $config = $class->merge_config_hashes( $config, {} );
100 $meta->add_package_symbol('$config', \ $config);
107 unless( defined $config ){
109 $meta->add_package_symbol('$config', \ $config) unless @_;
113 my $from_args = { %{@_ > 1 ? {@_} : $_[0]} };
114 my $new_config = $class->merge_config_hashes( $config, $from_args);
115 $meta->add_package_symbol('$config', \ $new_config);
121 sub merge_config_hashes {
122 my ( $self, $lefthash, $righthash ) = @_;
124 return Catalyst::Utils::merge_hashes( $lefthash, $righthash );
129 Catalyst::Exception->throw( message => ( ref $_[0] || $_[0] )
130 . " did not override Catalyst::Component::process" );
134 __PACKAGE__->meta->make_immutable;
141 =head2 new($c, $arguments)
143 Called by COMPONENT to instantiate the component; should return an object
144 to be stored in the application's component hash.
146 =head2 COMPONENT($c, $arguments)
148 If this method is present (as it is on all Catalyst::Component subclasses,
149 it is called by Catalyst during setup_components with the application class
150 as $c and any config entry on the application for this component (for example,
151 in the case of MyApp::Controller::Foo this would be
152 MyApp->config->{'Controller::Foo'}). The arguments are expected to be a
153 hashref and are merged with the __PACKAGE__->config hashref before calling
154 ->new to instantiate the component.
158 =head2 $c->config($hashref)
160 =head2 $c->config($key, $value, ...)
162 Accessor for this component's config hash. Config values can be set as
163 key value pair, or you can specify a hashref. In either case the keys
164 will be merged with any existing config settings. Each component in
165 a Catalyst application has it's own config hash.
169 This is the default method called on a Catalyst component in the dispatcher.
170 For instance, Views implement this action to render the response body
171 when you forward to them. The default is an abstract method.
173 =head2 $c->merge_config_hashes( $hashref, $hashref )
175 Merges two hashes together recursively, giving right-hand precedence.
176 Alias for the method in L<Catalyst::Utils>.
178 =head1 OPTIONAL METHODS
180 =head2 ACCEPT_CONTEXT($c, @args)
182 Catalyst components are normally initalized during server startup, either
183 as a Class or a Instance. However, some components require information about
184 the current request. To do so, they can implement an ACCEPT_CONTEXT method.
186 If this method is present, it is called during $c->comp/controller/model/view
187 with the current $c and any additional args (e.g. $c->model('Foo', qw/bar baz/)
188 would cause your MyApp::Model::Foo instance's ACCEPT_CONTEXT to be called with
189 ($c, 'bar', 'baz')) and the return value of this method is returned to the
190 calling code in the application rather than the component itself.
194 L<Catalyst>, L<Catalyst::Model>, L<Catalyst::View>, L<Catalyst::Controller>.
198 Sebastian Riedel, C<sri@cpan.org>
199 Marcus Ramberg, C<mramberg@cpan.org>
200 Matt S Trout, C<mst@shadowcatsystems.co.uk>
204 This program is free software, you can redistribute it and/or modify it under
205 the same terms as Perl itself.