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158c88c0 |
1 | package Catalyst::Component; |
2 | |
a7caa492 |
3 | use Moose; |
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4 | use Class::MOP; |
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5 | use Class::MOP::Object; |
e8b9f2a9 |
6 | use Catalyst::Utils; |
cb89a296 |
7 | use Class::C3::Adopt::NEXT; |
5d02e790 |
8 | use Devel::InnerPackage (); |
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9 | use MRO::Compat; |
10 | use mro 'c3'; |
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11 | use Scalar::Util 'blessed'; |
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12 | use namespace::clean -except => 'meta'; |
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13 | |
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14 | with 'MooseX::Emulate::Class::Accessor::Fast'; |
15 | with 'Catalyst::ClassData'; |
16 | |
17 | |
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18 | =head1 NAME |
19 | |
20 | Catalyst::Component - Catalyst Component Base Class |
21 | |
22 | =head1 SYNOPSIS |
23 | |
24 | # lib/MyApp/Model/Something.pm |
25 | package MyApp::Model::Something; |
26 | |
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27 | use base 'Catalyst::Component'; |
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28 | |
29 | __PACKAGE__->config( foo => 'bar' ); |
30 | |
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31 | has foo => ( |
32 | is => 'ro', |
33 | ); |
34 | |
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35 | sub test { |
36 | my $self = shift; |
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37 | return $self->foo; |
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38 | } |
39 | |
40 | sub forward_to_me { |
41 | my ( $self, $c ) = @_; |
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42 | $c->response->output( $self->foo ); |
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43 | } |
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44 | |
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45 | 1; |
46 | |
47 | # Methods can be a request step |
48 | $c->forward(qw/MyApp::Model::Something forward_to_me/); |
49 | |
50 | # Or just methods |
51 | print $c->comp('MyApp::Model::Something')->test; |
52 | |
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53 | print $c->comp('MyApp::Model::Something')->foo; |
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54 | |
55 | =head1 DESCRIPTION |
56 | |
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57 | This is the universal base class for Catalyst components |
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58 | (Model/View/Controller). |
59 | |
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60 | It provides you with a generic new() for component construction through Catalyst's |
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61 | component loader with config() support and a process() method placeholder. |
62 | |
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63 | B<Note> that calling C<< $self->config >> inside a component is strongly |
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64 | not recommended - the correctly merged config should have already been |
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65 | passed to the constructor and stored in attributes - accessing |
66 | the config accessor directly from an instance is likely to get the |
67 | wrong values (as it only holds the class wide config, not things loaded |
68 | from the config file!) |
69 | |
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70 | =cut |
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71 | |
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72 | __PACKAGE__->mk_classdata('_plugins'); |
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73 | __PACKAGE__->mk_classdata('_config'); |
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74 | |
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75 | has catalyst_component_name => ( is => 'ro' ); # Cannot be required => 1 as context |
d2598ac8 |
76 | # class @ISA component - HATE |
77 | # Make accessor callable as a class method, as we need to call setup_actions |
78 | # on the application class, which we don't have an instance of, ewwwww |
e65d000f |
79 | # Also, naughty modules like Catalyst::View::JSON try to write to _everything_, |
80 | # so spit a warning, ignore that (and try to do the right thing anyway) here.. |
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81 | around catalyst_component_name => sub { |
d2598ac8 |
82 | my ($orig, $self) = (shift, shift); |
8f6cebb2 |
83 | Carp::cluck("Tried to write to the catalyst_component_name accessor - is your component broken or just mad? (Write ignored - using default value.)") if scalar @_; |
e65d000f |
84 | blessed($self) ? $self->$orig() || blessed($self) : $self; |
d2598ac8 |
85 | }; |
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86 | |
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87 | sub BUILDARGS { |
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88 | my $class = shift; |
89 | my $args = {}; |
90 | |
91 | if (@_ == 1) { |
92 | $args = $_[0] if ref($_[0]) eq 'HASH'; |
93 | } elsif (@_ == 2) { # is it ($app, $args) or foo => 'bar' ? |
94 | if (blessed($_[0])) { |
95 | $args = $_[1] if ref($_[1]) eq 'HASH'; |
96 | } elsif (Class::MOP::is_class_loaded($_[0]) && |
97 | $_[0]->isa('Catalyst') && ref($_[1]) eq 'HASH') { |
98 | $args = $_[1]; |
7a5ed4ef |
99 | } else { |
100 | $args = +{ @_ }; |
101 | } |
102 | } elsif (@_ % 2 == 0) { |
103 | $args = +{ @_ }; |
104 | } |
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105 | |
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106 | return $class->merge_config_hashes( $class->config, $args ); |
2ef59958 |
107 | } |
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108 | |
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109 | sub COMPONENT { |
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110 | my ( $class, $c ) = @_; |
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111 | |
112 | # Temporary fix, some components does not pass context to constructor |
113 | my $arguments = ( ref( $_[-1] ) eq 'HASH' ) ? $_[-1] : {}; |
1b79e199 |
114 | if ( my $next = $class->next::can ) { |
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115 | my ($next_package) = Class::MOP::get_code_info($next); |
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116 | warn "There is a COMPONENT method resolving after Catalyst::Component in ${next_package}.\n"; |
117 | warn "This behavior can no longer be supported, and so your application is probably broken.\n"; |
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118 | warn "Your linearized isa hierarchy is: " . join(', ', @{ mro::get_linear_isa($class) }) . "\n"; |
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119 | warn "Please see perldoc Catalyst::Upgrading for more information about this issue.\n"; |
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120 | } |
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121 | return $class->new($c, $arguments); |
22247e54 |
122 | } |
123 | |
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124 | sub config { |
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125 | my $self = shift; |
df960201 |
126 | # Uncomment once sane to do so |
127 | #Carp::cluck("config method called on instance") if ref $self; |
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128 | my $config = $self->_config || {}; |
129 | if (@_) { |
130 | my $newconfig = { %{@_ > 1 ? {@_} : $_[0]} }; |
131 | $self->_config( |
132 | $self->merge_config_hashes( $config, $newconfig ) |
133 | ); |
134 | } else { |
135 | # this is a bit of a kludge, required to make |
136 | # __PACKAGE__->config->{foo} = 'bar'; |
edffeb5a |
137 | # work in a subclass. |
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138 | # TODO maybe this should be a ClassData option? |
e106a59f |
139 | my $class = blessed($self) || $self; |
140 | my $meta = Class::MOP::get_metaclass_by_name($class); |
fc9ec364 |
141 | unless (${ $meta->get_or_add_package_symbol('$_config') }) { |
c03aaf03 |
142 | # Call merge_hashes to ensure we deep copy the parent |
143 | # config onto the subclass |
144 | $self->_config( Catalyst::Utils::merge_hashes($config, {}) ); |
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145 | } |
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146 | } |
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147 | return $self->_config; |
158c88c0 |
148 | } |
149 | |
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150 | sub merge_config_hashes { |
151 | my ( $self, $lefthash, $righthash ) = @_; |
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152 | |
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153 | return Catalyst::Utils::merge_hashes( $lefthash, $righthash ); |
154 | } |
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155 | |
156 | sub process { |
157 | |
158 | Catalyst::Exception->throw( message => ( ref $_[0] || $_[0] ) |
159 | . " did not override Catalyst::Component::process" ); |
160 | } |
161 | |
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162 | sub expand_modules { |
163 | my ($class, $component) = @_; |
164 | return Devel::InnerPackage::list_packages( $component ); |
165 | } |
166 | |
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167 | __PACKAGE__->meta->make_immutable; |
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168 | |
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169 | 1; |
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170 | |
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171 | __END__ |
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172 | |
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173 | =head1 METHODS |
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174 | |
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175 | =head2 new($app, $arguments) |
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176 | |
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177 | Called by COMPONENT to instantiate the component; should return an object |
178 | to be stored in the application's component hash. |
179 | |
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180 | =head2 COMPONENT |
181 | |
182 | C<< my $component_instance = $component->COMPONENT($app, $arguments); >> |
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183 | |
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184 | If this method is present (as it is on all Catalyst::Component subclasses), |
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185 | it is called by Catalyst during setup_components with the application class |
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186 | as $app and any config entry on the application for this component (for example, |
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187 | in the case of MyApp::Controller::Foo this would be |
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188 | C<< MyApp->config('Controller::Foo' => \%conf >>). |
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189 | |
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190 | The arguments are expected to be a hashref and are merged with the |
191 | C<< __PACKAGE__->config >> hashref before calling C<< ->new >> |
192 | to instantiate the component. |
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193 | |
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194 | You can override it in your components to do custom construction, using |
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195 | something like this: |
196 | |
197 | sub COMPONENT { |
198 | my ($class, $app, $args) = @_; |
2a787673 |
199 | $args = $class->merge_config_hashes($class->config, $args); |
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200 | return $class->new($app, $args); |
201 | } |
202 | |
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203 | =head2 $c->config |
204 | |
205 | =head2 $c->config($hashref) |
206 | |
207 | =head2 $c->config($key, $value, ...) |
208 | |
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209 | Accessor for this component's config hash. Config values can be set as |
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210 | key value pair, or you can specify a hashref. In either case the keys |
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211 | will be merged with any existing config settings. Each component in |
212 | a Catalyst application has its own config hash. |
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213 | |
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214 | The component's config hash is merged with any config entry on the |
215 | application for this component and passed to C<new()> (as mentioned |
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216 | above at L</COMPONENT>). The recommended practice to access the merged |
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217 | config is to use a Moose attribute for each config entry on the |
218 | receiving component. |
219 | |
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220 | =head2 $c->process() |
221 | |
222 | This is the default method called on a Catalyst component in the dispatcher. |
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223 | For instance, Views implement this action to render the response body |
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224 | when you forward to them. The default is an abstract method. |
225 | |
226 | =head2 $c->merge_config_hashes( $hashref, $hashref ) |
227 | |
228 | Merges two hashes together recursively, giving right-hand precedence. |
229 | Alias for the method in L<Catalyst::Utils>. |
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230 | |
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231 | =head2 $c->expand_modules( $setup_component_config ) |
232 | |
233 | Return a list of extra components that this component has created. By default, |
234 | it just looks for a list of inner packages of this component |
235 | |
236 | =cut |
237 | |
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238 | =head1 OPTIONAL METHODS |
239 | |
240 | =head2 ACCEPT_CONTEXT($c, @args) |
241 | |
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242 | Catalyst components are normally initialized during server startup, either |
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243 | as a Class or a Instance. However, some components require information about |
244 | the current request. To do so, they can implement an ACCEPT_CONTEXT method. |
245 | |
246 | If this method is present, it is called during $c->comp/controller/model/view |
247 | with the current $c and any additional args (e.g. $c->model('Foo', qw/bar baz/) |
248 | would cause your MyApp::Model::Foo instance's ACCEPT_CONTEXT to be called with |
249 | ($c, 'bar', 'baz')) and the return value of this method is returned to the |
250 | calling code in the application rather than the component itself. |
251 | |
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252 | =head1 SEE ALSO |
253 | |
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254 | L<Catalyst>, L<Catalyst::Model>, L<Catalyst::View>, L<Catalyst::Controller>. |
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255 | |
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256 | =head1 AUTHORS |
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257 | |
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258 | Catalyst Contributors, see Catalyst.pm |
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259 | |
260 | =head1 COPYRIGHT |
261 | |
536bee89 |
262 | This library is free software. You can redistribute it and/or modify it under |
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263 | the same terms as Perl itself. |
264 | |
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265 | =cut |