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1 | package Catalyst::Component; |
2 | |
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3 | use Moose; |
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4 | use Class::MOP; |
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5 | use Class::MOP::Object; |
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6 | use Catalyst::Utils; |
cb89a296 |
7 | use Class::C3::Adopt::NEXT; |
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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<< $self->config >> inside a component is strongly |
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64 | not recommended - the correctly merged config should have already been |
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65 | passed to the constructor and stored in attributes - accessing |
66 | the config accessor directly from an instance is likely to get the |
67 | wrong values (as it only holds the class wide config, not things loaded |
68 | from the config file!) |
69 | |
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70 | =cut |
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71 | |
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72 | __PACKAGE__->mk_classdata('_plugins'); |
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73 | __PACKAGE__->mk_classdata('_config'); |
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74 | |
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75 | has catalyst_component_name => ( is => 'ro' ); # Cannot be required => 1 as context |
d2598ac8 |
76 | # class @ISA component - HATE |
06eea452 |
77 | # Naughty modules like Catalyst::View::JSON try to write to _everything_, |
e65d000f |
78 | # so spit a warning, ignore that (and try to do the right thing anyway) here.. |
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79 | around catalyst_component_name => sub { |
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80 | my ($orig, $self) = (shift, shift); |
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81 | 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 @_; |
06eea452 |
82 | return $self->$orig() || blessed($self); |
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83 | }; |
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84 | |
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85 | sub BUILDARGS { |
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86 | my $class = shift; |
87 | my $args = {}; |
88 | |
89 | if (@_ == 1) { |
90 | $args = $_[0] if ref($_[0]) eq 'HASH'; |
91 | } elsif (@_ == 2) { # is it ($app, $args) or foo => 'bar' ? |
92 | if (blessed($_[0])) { |
93 | $args = $_[1] if ref($_[1]) eq 'HASH'; |
94 | } elsif (Class::MOP::is_class_loaded($_[0]) && |
95 | $_[0]->isa('Catalyst') && ref($_[1]) eq 'HASH') { |
96 | $args = $_[1]; |
7a5ed4ef |
97 | } else { |
98 | $args = +{ @_ }; |
99 | } |
100 | } elsif (@_ % 2 == 0) { |
101 | $args = +{ @_ }; |
102 | } |
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103 | |
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104 | return $class->merge_config_hashes( $class->config, $args ); |
2ef59958 |
105 | } |
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106 | |
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107 | sub COMPONENT { |
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108 | my ( $class, $c ) = @_; |
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109 | |
110 | # Temporary fix, some components does not pass context to constructor |
111 | my $arguments = ( ref( $_[-1] ) eq 'HASH' ) ? $_[-1] : {}; |
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112 | if ( my $next = $class->next::can ) { |
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113 | my ($next_package) = Class::MOP::get_code_info($next); |
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114 | warn "There is a COMPONENT method resolving after Catalyst::Component in ${next_package}.\n"; |
115 | warn "This behavior can no longer be supported, and so your application is probably broken.\n"; |
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116 | warn "Your linearized isa hierarchy is: " . join(', ', @{ mro::get_linear_isa($class) }) . "\n"; |
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117 | warn "Please see perldoc Catalyst::Upgrading for more information about this issue.\n"; |
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118 | } |
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119 | return $class->new($c, $arguments); |
22247e54 |
120 | } |
121 | |
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122 | sub config { |
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123 | my $self = shift; |
df960201 |
124 | # Uncomment once sane to do so |
125 | #Carp::cluck("config method called on instance") if ref $self; |
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126 | my $config = $self->_config || {}; |
127 | if (@_) { |
128 | my $newconfig = { %{@_ > 1 ? {@_} : $_[0]} }; |
129 | $self->_config( |
130 | $self->merge_config_hashes( $config, $newconfig ) |
131 | ); |
132 | } else { |
133 | # this is a bit of a kludge, required to make |
134 | # __PACKAGE__->config->{foo} = 'bar'; |
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135 | # work in a subclass. |
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136 | # TODO maybe this should be a ClassData option? |
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137 | my $class = blessed($self) || $self; |
138 | my $meta = Class::MOP::get_metaclass_by_name($class); |
fc9ec364 |
139 | unless (${ $meta->get_or_add_package_symbol('$_config') }) { |
c03aaf03 |
140 | # Call merge_hashes to ensure we deep copy the parent |
141 | # config onto the subclass |
142 | $self->_config( Catalyst::Utils::merge_hashes($config, {}) ); |
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143 | } |
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144 | } |
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145 | return $self->_config; |
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146 | } |
147 | |
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148 | sub merge_config_hashes { |
149 | my ( $self, $lefthash, $righthash ) = @_; |
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150 | |
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151 | return Catalyst::Utils::merge_hashes( $lefthash, $righthash ); |
152 | } |
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153 | |
154 | sub process { |
155 | |
156 | Catalyst::Exception->throw( message => ( ref $_[0] || $_[0] ) |
157 | . " did not override Catalyst::Component::process" ); |
158 | } |
159 | |
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160 | sub expand_modules { |
161 | my ($class, $component) = @_; |
162 | return Devel::InnerPackage::list_packages( $component ); |
163 | } |
164 | |
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165 | __PACKAGE__->meta->make_immutable; |
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166 | |
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167 | 1; |
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168 | |
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169 | __END__ |
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170 | |
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171 | =head1 METHODS |
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172 | |
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173 | =head2 new($app, $arguments) |
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174 | |
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175 | Called by COMPONENT to instantiate the component; should return an object |
176 | to be stored in the application's component hash. |
177 | |
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178 | =head2 COMPONENT |
179 | |
180 | C<< my $component_instance = $component->COMPONENT($app, $arguments); >> |
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181 | |
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182 | If this method is present (as it is on all Catalyst::Component subclasses), |
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183 | it is called by Catalyst during setup_components with the application class |
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184 | as $app and any config entry on the application for this component (for example, |
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185 | in the case of MyApp::Controller::Foo this would be |
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186 | C<< MyApp->config('Controller::Foo' => \%conf >>). |
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187 | |
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188 | The arguments are expected to be a hashref and are merged with the |
189 | C<< __PACKAGE__->config >> hashref before calling C<< ->new >> |
190 | to instantiate the component. |
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191 | |
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192 | You can override it in your components to do custom construction, using |
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193 | something like this: |
194 | |
195 | sub COMPONENT { |
196 | my ($class, $app, $args) = @_; |
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197 | $args = $class->merge_config_hashes($class->config, $args); |
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198 | return $class->new($app, $args); |
199 | } |
200 | |
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201 | =head2 $c->config |
202 | |
203 | =head2 $c->config($hashref) |
204 | |
205 | =head2 $c->config($key, $value, ...) |
206 | |
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207 | Accessor for this component's config hash. Config values can be set as |
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208 | key value pair, or you can specify a hashref. In either case the keys |
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209 | will be merged with any existing config settings. Each component in |
210 | a Catalyst application has its own config hash. |
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211 | |
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212 | The component's config hash is merged with any config entry on the |
213 | application for this component and passed to C<new()> (as mentioned |
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214 | above at L</COMPONENT>). The recommended practice to access the merged |
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215 | config is to use a Moose attribute for each config entry on the |
216 | receiving component. |
217 | |
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218 | =head2 $c->process() |
219 | |
220 | This is the default method called on a Catalyst component in the dispatcher. |
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221 | For instance, Views implement this action to render the response body |
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222 | when you forward to them. The default is an abstract method. |
223 | |
224 | =head2 $c->merge_config_hashes( $hashref, $hashref ) |
225 | |
226 | Merges two hashes together recursively, giving right-hand precedence. |
227 | Alias for the method in L<Catalyst::Utils>. |
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228 | |
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229 | =head2 $c->expand_modules( $setup_component_config ) |
230 | |
231 | Return a list of extra components that this component has created. By default, |
232 | it just looks for a list of inner packages of this component |
233 | |
234 | =cut |
235 | |
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236 | =head1 OPTIONAL METHODS |
237 | |
238 | =head2 ACCEPT_CONTEXT($c, @args) |
239 | |
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240 | Catalyst components are normally initialized during server startup, either |
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241 | as a Class or a Instance. However, some components require information about |
242 | the current request. To do so, they can implement an ACCEPT_CONTEXT method. |
243 | |
244 | If this method is present, it is called during $c->comp/controller/model/view |
245 | with the current $c and any additional args (e.g. $c->model('Foo', qw/bar baz/) |
246 | would cause your MyApp::Model::Foo instance's ACCEPT_CONTEXT to be called with |
247 | ($c, 'bar', 'baz')) and the return value of this method is returned to the |
248 | calling code in the application rather than the component itself. |
249 | |
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250 | =head1 SEE ALSO |
251 | |
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252 | L<Catalyst>, L<Catalyst::Model>, L<Catalyst::View>, L<Catalyst::Controller>. |
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253 | |
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254 | =head1 AUTHORS |
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255 | |
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256 | Catalyst Contributors, see Catalyst.pm |
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257 | |
258 | =head1 COPYRIGHT |
259 | |
536bee89 |
260 | This library is free software. You can redistribute it and/or modify it under |
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261 | the same terms as Perl itself. |
262 | |
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263 | =cut |