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');
58 __PACKAGE__->mk_classdata('_config');
63 # Temporary fix, some components does not pass context to constructor
64 my $arguments = ( ref( $_[-1] ) eq 'HASH' ) ? $_[-1] : {};
66 my $args = $self->merge_config_hashes( $self->config, $arguments );
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 $config = $self->_config || {};
89 my $newconfig = { %{@_ > 1 ? {@_} : $_[0]} };
91 $self->merge_config_hashes( $config, $newconfig )
94 # this is a bit of a kludge, required to make
95 # __PACKAGE__->config->{foo} = 'bar';
96 # work in a subclass. If we don't have the package symbol in the
97 # current class we know we need to copy up to ours, which calling
98 # the setter will do for us.
100 unless ($self->meta->has_package_symbol('$_config')) {
102 $config = $self->merge_config_hashes( $config, {} );
103 $self->_config( $config );
109 sub merge_config_hashes {
110 my ( $self, $lefthash, $righthash ) = @_;
112 return Catalyst::Utils::merge_hashes( $lefthash, $righthash );
117 Catalyst::Exception->throw( message => ( ref $_[0] || $_[0] )
118 . " did not override Catalyst::Component::process" );
123 __PACKAGE__->meta->make_immutable;
130 =head2 new($c, $arguments)
132 Called by COMPONENT to instantiate the component; should return an object
133 to be stored in the application's component hash.
135 =head2 COMPONENT($c, $arguments)
137 If this method is present (as it is on all Catalyst::Component subclasses,
138 it is called by Catalyst during setup_components with the application class
139 as $c and any config entry on the application for this component (for example,
140 in the case of MyApp::Controller::Foo this would be
141 MyApp->config->{'Controller::Foo'}). The arguments are expected to be a
142 hashref and are merged with the __PACKAGE__->config hashref before calling
143 ->new to instantiate the component.
147 =head2 $c->config($hashref)
149 =head2 $c->config($key, $value, ...)
151 Accessor for this component's config hash. Config values can be set as
152 key value pair, or you can specify a hashref. In either case the keys
153 will be merged with any existing config settings. Each component in
154 a Catalyst application has it's own config hash.
158 This is the default method called on a Catalyst component in the dispatcher.
159 For instance, Views implement this action to render the response body
160 when you forward to them. The default is an abstract method.
162 =head2 $c->merge_config_hashes( $hashref, $hashref )
164 Merges two hashes together recursively, giving right-hand precedence.
165 Alias for the method in L<Catalyst::Utils>.
167 =head1 OPTIONAL METHODS
169 =head2 ACCEPT_CONTEXT($c, @args)
171 Catalyst components are normally initalized during server startup, either
172 as a Class or a Instance. However, some components require information about
173 the current request. To do so, they can implement an ACCEPT_CONTEXT method.
175 If this method is present, it is called during $c->comp/controller/model/view
176 with the current $c and any additional args (e.g. $c->model('Foo', qw/bar baz/)
177 would cause your MyApp::Model::Foo instance's ACCEPT_CONTEXT to be called with
178 ($c, 'bar', 'baz')) and the return value of this method is returned to the
179 calling code in the application rather than the component itself.
183 L<Catalyst>, L<Catalyst::Model>, L<Catalyst::View>, L<Catalyst::Controller>.
187 Catalyst Contributors, see Catalyst.pm
191 This program is free software, you can redistribute it and/or modify it under
192 the same terms as Perl itself.