Commit | Line | Data |
fcd84ca9 |
1 | |
2 | package Moose; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
ecb1297a |
7 | use 5.008; |
8 | |
fb4fcfee |
9 | our $VERSION = '0.57'; |
75b95414 |
10 | $VERSION = eval $VERSION; |
d44714be |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
fcd84ca9 |
12 | |
21f1e231 |
13 | use Scalar::Util 'blessed'; |
c0b37457 |
14 | use Carp 'confess', 'croak', 'cluck'; |
fcd84ca9 |
15 | |
5bd4db9b |
16 | use Moose::Exporter; |
7f18097c |
17 | |
ecfea998 |
18 | use Class::MOP 0.65; |
ef1d5f4b |
19 | |
c0e30cf5 |
20 | use Moose::Meta::Class; |
7415b2cb |
21 | use Moose::Meta::TypeConstraint; |
7c13858b |
22 | use Moose::Meta::TypeCoercion; |
78cd1d3b |
23 | use Moose::Meta::Attribute; |
ddd0ec20 |
24 | use Moose::Meta::Instance; |
c0e30cf5 |
25 | |
0779da92 |
26 | use Moose::Object; |
27 | |
d67145ed |
28 | use Moose::Meta::Role; |
0779da92 |
29 | use Moose::Meta::Role::Composite; |
30 | use Moose::Meta::Role::Application; |
31 | use Moose::Meta::Role::Application::RoleSummation; |
32 | use Moose::Meta::Role::Application::ToClass; |
33 | use Moose::Meta::Role::Application::ToRole; |
34 | use Moose::Meta::Role::Application::ToInstance; |
d67145ed |
35 | |
7415b2cb |
36 | use Moose::Util::TypeConstraints; |
d7d8a8c7 |
37 | use Moose::Util (); |
a15dff8d |
38 | |
c245d69b |
39 | sub throw_error { |
40 | # FIXME This |
41 | shift; |
42 | goto \&confess |
43 | } |
4c0b3599 |
44 | |
5bd4db9b |
45 | sub extends { |
97a93056 |
46 | my $class = shift; |
3d544ed5 |
47 | |
5bd4db9b |
48 | croak "Must derive at least one class" unless @_; |
9bcfbab1 |
49 | |
5bd4db9b |
50 | my @supers = @_; |
51 | foreach my $super (@supers) { |
52 | Class::MOP::load_class($super); |
53 | croak "You cannot inherit from a Moose Role ($super)" |
54 | if $super->can('meta') && |
55 | blessed $super->meta && |
56 | $super->meta->isa('Moose::Meta::Role') |
c92c1205 |
57 | } |
5bee491d |
58 | |
26fbace8 |
59 | |
86dd5d11 |
60 | |
5bd4db9b |
61 | # this checks the metaclass to make sure |
62 | # it is correct, sometimes it can get out |
63 | # of sync when the classes are being built |
50d5df60 |
64 | my $meta = Moose::Meta::Class->initialize($class)->_fix_metaclass_incompatability(@supers); |
5bd4db9b |
65 | $meta->superclasses(@supers); |
66 | } |
a3c7e2fe |
67 | |
5bd4db9b |
68 | sub with { |
97a93056 |
69 | my $class = shift; |
aedcb7d9 |
70 | Moose::Util::apply_all_roles(Class::MOP::Class->initialize($class), @_); |
5bd4db9b |
71 | } |
9bcfbab1 |
72 | |
5bd4db9b |
73 | sub has { |
97a93056 |
74 | my $class = shift; |
5bd4db9b |
75 | my $name = shift; |
76 | croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1; |
77 | my %options = @_; |
78 | my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; |
aedcb7d9 |
79 | Class::MOP::Class->initialize($class)->add_attribute( $_, %options ) for @$attrs; |
5bd4db9b |
80 | } |
9bcfbab1 |
81 | |
5bd4db9b |
82 | sub before { |
97a93056 |
83 | my $class = shift; |
5bd4db9b |
84 | Moose::Util::add_method_modifier($class, 'before', \@_); |
85 | } |
86 | |
87 | sub after { |
97a93056 |
88 | my $class = shift; |
5bd4db9b |
89 | Moose::Util::add_method_modifier($class, 'after', \@_); |
90 | } |
91 | |
92 | sub around { |
97a93056 |
93 | my $class = shift; |
5bd4db9b |
94 | Moose::Util::add_method_modifier($class, 'around', \@_); |
95 | } |
96 | |
97 | sub super { |
98 | return unless our $SUPER_BODY; $SUPER_BODY->(our @SUPER_ARGS); |
99 | } |
9bcfbab1 |
100 | |
5bd4db9b |
101 | sub override { |
97a93056 |
102 | my $class = shift; |
5bd4db9b |
103 | my ( $name, $method ) = @_; |
aedcb7d9 |
104 | Class::MOP::Class->initialize($class)->add_override_method_modifier( $name => $method ); |
5bd4db9b |
105 | } |
9bcfbab1 |
106 | |
5bd4db9b |
107 | sub inner { |
108 | my $pkg = caller(); |
109 | our ( %INNER_BODY, %INNER_ARGS ); |
110 | |
111 | if ( my $body = $INNER_BODY{$pkg} ) { |
112 | my @args = @{ $INNER_ARGS{$pkg} }; |
113 | local $INNER_ARGS{$pkg}; |
114 | local $INNER_BODY{$pkg}; |
115 | return $body->(@args); |
116 | } else { |
117 | return; |
ce265cc3 |
118 | } |
5bd4db9b |
119 | } |
9bcfbab1 |
120 | |
5bd4db9b |
121 | sub augment { |
97a93056 |
122 | my $class = shift; |
5bd4db9b |
123 | my ( $name, $method ) = @_; |
aedcb7d9 |
124 | Class::MOP::Class->initialize($class)->add_augment_method_modifier( $name => $method ); |
ce265cc3 |
125 | } |
9bcfbab1 |
126 | |
5bd4db9b |
127 | sub make_immutable { |
97a93056 |
128 | my $class = shift; |
5bd4db9b |
129 | cluck "The make_immutable keyword has been deprecated, " . |
130 | "please go back to __PACKAGE__->meta->make_immutable\n"; |
aedcb7d9 |
131 | Class::MOP::Class->initialize($class)->make_immutable(@_); |
5bd4db9b |
132 | } |
9bcfbab1 |
133 | |
aedcb7d9 |
134 | Moose::Exporter->setup_import_methods( |
97a93056 |
135 | with_caller => [ |
136 | qw( extends with has before after around override augment make_immutable ) |
137 | ], |
138 | as_is => [ |
139 | qw( super inner ), |
5bd4db9b |
140 | \&Carp::confess, |
141 | \&Scalar::Util::blessed, |
142 | ], |
143 | ); |
144 | |
cc841c0e |
145 | sub init_meta { |
085fba61 |
146 | # This used to be called as a function. This hack preserves |
147 | # backwards compatibility. |
148 | if ( $_[0] ne __PACKAGE__ ) { |
149 | return __PACKAGE__->init_meta( |
150 | for_class => $_[0], |
151 | base_class => $_[1], |
152 | metaclass => $_[2], |
153 | ); |
154 | } |
7c4676ef |
155 | |
0338a411 |
156 | shift; |
157 | my %args = @_; |
158 | |
159 | my $class = $args{for_class} |
c245d69b |
160 | or Moose->throw_error("Cannot call init_meta without specifying a for_class"); |
085fba61 |
161 | my $base_class = $args{base_class} || 'Moose::Object'; |
162 | my $metaclass = $args{metaclass} || 'Moose::Meta::Class'; |
cc841c0e |
163 | |
c245d69b |
164 | Moose->throw_error("The Metaclass $metaclass must be a subclass of Moose::Meta::Class.") |
cc841c0e |
165 | unless $metaclass->isa('Moose::Meta::Class'); |
166 | |
167 | # make a subtype for each Moose class |
168 | class_type($class) |
169 | unless find_type_constraint($class); |
170 | |
171 | my $meta; |
50d5df60 |
172 | |
173 | if ( $meta = Class::MOP::get_metaclass_by_name($class) ) { |
174 | unless ( $meta->isa("Moose::Meta::Class") ) { |
c245d69b |
175 | Moose->throw_error("$class already has a metaclass, but it does not inherit $metaclass ($meta)"); |
50d5df60 |
176 | } |
177 | } else { |
178 | # no metaclass, no 'meta' method |
179 | |
180 | # now we check whether our ancestors have metaclass, and if so borrow that |
181 | my ( undef, @isa ) = @{ $class->mro::get_linear_isa }; |
182 | |
183 | foreach my $ancestor ( @isa ) { |
184 | my $ancestor_meta = Class::MOP::get_metaclass_by_name($ancestor) || next; |
185 | |
186 | my $ancestor_meta_class = ($ancestor_meta->is_immutable |
187 | ? $ancestor_meta->get_mutable_metaclass_name |
188 | : ref($ancestor_meta)); |
189 | |
190 | # if we have an ancestor metaclass that inherits $metaclass, we use |
191 | # that. This is like _fix_metaclass_incompatability, but we can do it now. |
192 | |
193 | # the case of having an ancestry is not very common, but arises in |
194 | # e.g. Reaction |
195 | unless ( $metaclass->isa( $ancestor_meta_class ) ) { |
196 | if ( $ancestor_meta_class->isa($metaclass) ) { |
197 | $metaclass = $ancestor_meta_class; |
198 | } |
199 | } |
200 | } |
201 | |
202 | $meta = $metaclass->initialize($class); |
203 | } |
204 | |
cc841c0e |
205 | if ( $class->can('meta') ) { |
50d5df60 |
206 | # check 'meta' method |
207 | |
208 | # it may be inherited |
209 | |
cc841c0e |
210 | # NOTE: |
211 | # this is the case where the metaclass pragma |
212 | # was used before the 'use Moose' statement to |
213 | # override a specific class |
50d5df60 |
214 | my $method_meta = $class->meta; |
215 | |
216 | ( blessed($method_meta) && $method_meta->isa('Moose::Meta::Class') ) |
c245d69b |
217 | || Moose->throw_error("$class already has a &meta function, but it does not return a Moose::Meta::Class ($meta)"); |
50d5df60 |
218 | |
219 | $meta = $method_meta; |
cc841c0e |
220 | } |
50d5df60 |
221 | |
222 | unless ( $meta->has_method("meta") ) { # don't overwrite |
223 | # also check for inherited non moose 'meta' method? |
224 | # FIXME also skip this if the user requested by passing an option |
cc841c0e |
225 | $meta->add_method( |
226 | 'meta' => sub { |
227 | # re-initialize so it inherits properly |
50d5df60 |
228 | $metaclass->initialize( ref($_[0]) || $_[0] ); |
cc841c0e |
229 | } |
230 | ); |
231 | } |
232 | |
233 | # make sure they inherit from Moose::Object |
234 | $meta->superclasses($base_class) |
235 | unless $meta->superclasses(); |
236 | |
237 | return $meta; |
238 | } |
239 | |
085fba61 |
240 | # This may be used in some older MooseX extensions. |
241 | sub _get_caller { |
242 | goto &Moose::Exporter::_get_caller; |
243 | } |
244 | |
8ecb1fa0 |
245 | ## make 'em all immutable |
246 | |
247 | $_->meta->make_immutable( |
0779da92 |
248 | inline_constructor => 1, |
249 | constructor_name => "_new", |
77a18c28 |
250 | inline_accessors => 1, # these are Class::MOP accessors, so they need inlining |
9bcfbab1 |
251 | ) |
0779da92 |
252 | for (qw( |
253 | Moose::Meta::Attribute |
254 | Moose::Meta::Class |
255 | Moose::Meta::Instance |
256 | |
257 | Moose::Meta::TypeConstraint |
258 | Moose::Meta::TypeConstraint::Union |
259 | Moose::Meta::TypeConstraint::Parameterized |
9ad786af |
260 | Moose::Meta::TypeConstraint::Parameterizable |
0779da92 |
261 | Moose::Meta::TypeConstraint::Enum |
262 | Moose::Meta::TypeConstraint::Class |
263 | Moose::Meta::TypeConstraint::Role |
264 | Moose::Meta::TypeConstraint::Registry |
265 | Moose::Meta::TypeCoercion |
266 | Moose::Meta::TypeCoercion::Union |
267 | |
268 | Moose::Meta::Method |
269 | Moose::Meta::Method::Accessor |
270 | Moose::Meta::Method::Constructor |
271 | Moose::Meta::Method::Destructor |
272 | Moose::Meta::Method::Overriden |
273 | Moose::Meta::Method::Augmented |
274 | |
275 | Moose::Meta::Role |
276 | Moose::Meta::Role::Method |
277 | Moose::Meta::Role::Method::Required |
278 | |
279 | Moose::Meta::Role::Composite |
280 | |
281 | Moose::Meta::Role::Application |
282 | Moose::Meta::Role::Application::RoleSummation |
283 | Moose::Meta::Role::Application::ToClass |
284 | Moose::Meta::Role::Application::ToRole |
285 | Moose::Meta::Role::Application::ToInstance |
0779da92 |
286 | )); |
8ecb1fa0 |
287 | |
fcd84ca9 |
288 | 1; |
289 | |
290 | __END__ |
291 | |
292 | =pod |
293 | |
294 | =head1 NAME |
295 | |
8bdc7f13 |
296 | Moose - A postmodern object system for Perl 5 |
fcd84ca9 |
297 | |
298 | =head1 SYNOPSIS |
e522431d |
299 | |
300 | package Point; |
1cd45431 |
301 | use Moose; # automatically turns on strict and warnings |
26fbace8 |
302 | |
43d599e5 |
303 | has 'x' => (is => 'rw', isa => 'Int'); |
304 | has 'y' => (is => 'rw', isa => 'Int'); |
26fbace8 |
305 | |
e522431d |
306 | sub clear { |
307 | my $self = shift; |
308 | $self->x(0); |
26fbace8 |
309 | $self->y(0); |
e522431d |
310 | } |
26fbace8 |
311 | |
e522431d |
312 | package Point3D; |
313 | use Moose; |
26fbace8 |
314 | |
e522431d |
315 | extends 'Point'; |
26fbace8 |
316 | |
43d599e5 |
317 | has 'z' => (is => 'rw', isa => 'Int'); |
26fbace8 |
318 | |
e522431d |
319 | after 'clear' => sub { |
320 | my $self = shift; |
43d599e5 |
321 | $self->z(0); |
26fbace8 |
322 | }; |
2c0cbef7 |
323 | |
fcd84ca9 |
324 | =head1 DESCRIPTION |
325 | |
26fbace8 |
326 | Moose is an extension of the Perl 5 object system. |
e522431d |
327 | |
9b9da6f1 |
328 | The main goal of Moose is to make Perl 5 Object Oriented programming |
329 | easier, more consistent and less tedious. With Moose you can to think |
6f894f30 |
330 | more about what you want to do and less about the mechanics of OOP. |
fcd84ca9 |
331 | |
6f894f30 |
332 | Additionally, Moose is built on top of L<Class::MOP>, which is a |
333 | metaclass system for Perl 5. This means that Moose not only makes |
334 | building normal Perl 5 objects better, but it provides the power of |
335 | metaclass programming as well. |
8bdc7f13 |
336 | |
f5909dca |
337 | =head2 New to Moose? |
338 | |
6f894f30 |
339 | If you're new to Moose, the best place to start is the L<Moose::Intro> |
340 | docs, followed by the L<Moose::Cookbook>. The intro will show you what |
341 | Moose is, and how it makes Perl 5 OO better. |
342 | |
343 | The cookbook recipes on Moose basics will get you up to speed with |
344 | many of Moose's features quickly. Once you have an idea of what Moose |
345 | can do, you can use the API documentation to get more detail on |
346 | features which interest you. |
f5909dca |
347 | |
28669f89 |
348 | =head2 Moose Extensions |
349 | |
12aed9a0 |
350 | The C<MooseX::> namespace is the official place to find Moose extensions. |
351 | These extensions can be found on the CPAN. The easiest way to find them |
352 | is to search for them (L<http://search.cpan.org/search?query=MooseX::>), |
353 | or to examine L<Task::Moose> which aims to keep an up-to-date, easily |
354 | installable list of Moose extensions. |
28669f89 |
355 | |
6ba6d68c |
356 | =head1 BUILDING CLASSES WITH MOOSE |
357 | |
68efb014 |
358 | Moose makes every attempt to provide as much convenience as possible during |
359 | class construction/definition, but still stay out of your way if you want it |
360 | to. Here are a few items to note when building classes with Moose. |
6ba6d68c |
361 | |
26fbace8 |
362 | Unless specified with C<extends>, any class which uses Moose will |
6ba6d68c |
363 | inherit from L<Moose::Object>. |
364 | |
1cd45431 |
365 | Moose will also manage all attributes (including inherited ones) that are |
366 | defined with C<has>. And (assuming you call C<new>, which is inherited from |
367 | L<Moose::Object>) this includes properly initializing all instance slots, |
368 | setting defaults where appropriate, and performing any type constraint checking |
369 | or coercion. |
6ba6d68c |
370 | |
004222dc |
371 | =head1 PROVIDED METHODS |
6ba6d68c |
372 | |
004222dc |
373 | Moose provides a number of methods to all your classes, mostly through the |
374 | inheritance of L<Moose::Object>. There is however, one exception. |
6ba6d68c |
375 | |
376 | =over 4 |
377 | |
378 | =item B<meta> |
379 | |
380 | This is a method which provides access to the current class's metaclass. |
381 | |
004222dc |
382 | =back |
383 | |
384 | =head1 EXPORTED FUNCTIONS |
385 | |
386 | Moose will export a number of functions into the class's namespace which |
387 | may then be used to set up the class. These functions all work directly |
388 | on the current class. |
389 | |
390 | =over 4 |
391 | |
6ba6d68c |
392 | =item B<extends (@superclasses)> |
393 | |
394 | This function will set the superclass(es) for the current class. |
395 | |
26fbace8 |
396 | This approach is recommended instead of C<use base>, because C<use base> |
397 | actually C<push>es onto the class's C<@ISA>, whereas C<extends> will |
398 | replace it. This is important to ensure that classes which do not have |
68efb014 |
399 | superclasses still properly inherit from L<Moose::Object>. |
6ba6d68c |
400 | |
43d599e5 |
401 | =item B<with (@roles)> |
e9ec68d6 |
402 | |
004222dc |
403 | This will apply a given set of C<@roles> to the local class. |
e9ec68d6 |
404 | |
cd7eeaf5 |
405 | =item B<has $name =E<gt> %options> |
6ba6d68c |
406 | |
26fbace8 |
407 | This will install an attribute of a given C<$name> into the current class. |
408 | The C<%options> are the same as those provided by |
409 | L<Class::MOP::Attribute>, in addition to the list below which are provided |
43d599e5 |
410 | by Moose (L<Moose::Meta::Attribute> to be more specific): |
6ba6d68c |
411 | |
412 | =over 4 |
413 | |
076c81ed |
414 | =item I<is =E<gt> 'rw'|'ro'> |
6ba6d68c |
415 | |
26fbace8 |
416 | The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read |
417 | only). These will create either a read/write accessor or a read-only |
6ba6d68c |
418 | accessor respectively, using the same name as the C<$name> of the attribute. |
419 | |
1cd45431 |
420 | If you need more control over how your accessors are named, you can use the |
421 | I<reader>, I<writer> and I<accessor> options inherited from |
004222dc |
422 | L<Class::MOP::Attribute>, however if you use those, you won't need the I<is> |
423 | option. |
6ba6d68c |
424 | |
076c81ed |
425 | =item I<isa =E<gt> $type_name> |
6ba6d68c |
426 | |
26fbace8 |
427 | The I<isa> option uses Moose's type constraint facilities to set up runtime |
428 | type checking for this attribute. Moose will perform the checks during class |
429 | construction, and within any accessors. The C<$type_name> argument must be a |
430 | string. The string may be either a class name or a type defined using |
9cca2e9e |
431 | Moose's type definition features. (Refer to L<Moose::Util::TypeConstraints> |
c2a69ef1 |
432 | for information on how to define a new type, and how to retrieve type meta-data). |
6ba6d68c |
433 | |
daea75c9 |
434 | =item I<coerce =E<gt> (1|0)> |
435 | |
26fbace8 |
436 | This will attempt to use coercion with the supplied type constraint to change |
437 | the value passed into any accessors or constructors. You B<must> have supplied |
5cfe3805 |
438 | a type constraint in order for this to work. See L<Moose::Cookbook::Basics::Recipe5> |
1cd45431 |
439 | for an example. |
daea75c9 |
440 | |
441 | =item I<does =E<gt> $role_name> |
442 | |
26fbace8 |
443 | This will accept the name of a role which the value stored in this attribute |
daea75c9 |
444 | is expected to have consumed. |
445 | |
446 | =item I<required =E<gt> (1|0)> |
447 | |
26fbace8 |
448 | This marks the attribute as being required. This means a I<defined> value must be |
449 | supplied during class construction, and the attribute may never be set to |
450 | C<undef> with an accessor. |
daea75c9 |
451 | |
452 | =item I<weak_ref =E<gt> (1|0)> |
453 | |
68efb014 |
454 | This will tell the class to store the value of this attribute as a weakened |
455 | reference. If an attribute is a weakened reference, it B<cannot> also be |
456 | coerced. |
daea75c9 |
457 | |
458 | =item I<lazy =E<gt> (1|0)> |
459 | |
26fbace8 |
460 | This will tell the class to not create this slot until absolutely necessary. |
daea75c9 |
461 | If an attribute is marked as lazy it B<must> have a default supplied. |
462 | |
9e93dd19 |
463 | =item I<auto_deref =E<gt> (1|0)> |
464 | |
26fbace8 |
465 | This tells the accessor whether to automatically dereference the value returned. |
1cd45431 |
466 | This is only legal if your C<isa> option is either C<ArrayRef> or C<HashRef>. |
9e93dd19 |
467 | |
65e14c86 |
468 | =item I<trigger =E<gt> $code> |
469 | |
470 | The I<trigger> option is a CODE reference which will be called after the value of |
471 | the attribute is set. The CODE ref will be passed the instance itself, the |
472 | updated value and the attribute meta-object (this is for more advanced fiddling |
473 | and can typically be ignored). You B<cannot> have a trigger on a read-only |
474 | attribute. |
daea75c9 |
475 | |
c84f324f |
476 | =item I<handles =E<gt> ARRAY | HASH | REGEXP | ROLE | CODE> |
2c0cbef7 |
477 | |
26fbace8 |
478 | The I<handles> option provides Moose classes with automated delegation features. |
479 | This is a pretty complex and powerful option. It accepts many different option |
480 | formats, each with its own benefits and drawbacks. |
38e3283b |
481 | |
1cd45431 |
482 | B<NOTE:> The class being delegated to does not need to be a Moose based class, |
483 | which is why this feature is especially useful when wrapping non-Moose classes. |
38e3283b |
484 | |
1cd45431 |
485 | All I<handles> option formats share the following traits: |
38e3283b |
486 | |
1cd45431 |
487 | You cannot override a locally defined method with a delegated method; an |
488 | exception will be thrown if you try. That is to say, if you define C<foo> in |
489 | your class, you cannot override it with a delegated C<foo>. This is almost never |
490 | something you would want to do, and if it is, you should do it by hand and not |
491 | use Moose. |
38e3283b |
492 | |
1cd45431 |
493 | You cannot override any of the methods found in Moose::Object, or the C<BUILD> |
494 | and C<DEMOLISH> methods. These will not throw an exception, but will silently |
495 | move on to the next method in the list. My reasoning for this is that you would |
496 | almost never want to do this, since it usually breaks your class. As with |
497 | overriding locally defined methods, if you do want to do this, you should do it |
498 | manually, not with Moose. |
38e3283b |
499 | |
f3c4e20e |
500 | You do not I<need> to have a reader (or accessor) for the attribute in order |
501 | to delegate to it. Moose will create a means of accessing the value for you, |
502 | however this will be several times B<less> efficient then if you had given |
503 | the attribute a reader (or accessor) to use. |
504 | |
38e3283b |
505 | Below is the documentation for each option format: |
506 | |
507 | =over 4 |
508 | |
509 | =item C<ARRAY> |
510 | |
26fbace8 |
511 | This is the most common usage for I<handles>. You basically pass a list of |
512 | method names to be delegated, and Moose will install a delegation method |
1cd45431 |
513 | for each one. |
38e3283b |
514 | |
515 | =item C<HASH> |
516 | |
26fbace8 |
517 | This is the second most common usage for I<handles>. Instead of a list of |
518 | method names, you pass a HASH ref where each key is the method name you |
519 | want installed locally, and its value is the name of the original method |
520 | in the class being delegated to. |
fd595040 |
521 | |
26fbace8 |
522 | This can be very useful for recursive classes like trees. Here is a |
5cfe3805 |
523 | quick example (soon to be expanded into a Moose::Cookbook recipe): |
38e3283b |
524 | |
1cd45431 |
525 | package Tree; |
38e3283b |
526 | use Moose; |
26fbace8 |
527 | |
38e3283b |
528 | has 'node' => (is => 'rw', isa => 'Any'); |
26fbace8 |
529 | |
38e3283b |
530 | has 'children' => ( |
531 | is => 'ro', |
532 | isa => 'ArrayRef', |
533 | default => sub { [] } |
534 | ); |
26fbace8 |
535 | |
38e3283b |
536 | has 'parent' => ( |
537 | is => 'rw', |
538 | isa => 'Tree', |
a4e516f6 |
539 | weak_ref => 1, |
38e3283b |
540 | handles => { |
541 | parent_node => 'node', |
26fbace8 |
542 | siblings => 'children', |
38e3283b |
543 | } |
544 | ); |
545 | |
1cd45431 |
546 | In this example, the Tree package gets C<parent_node> and C<siblings> methods, |
547 | which delegate to the C<node> and C<children> methods (respectively) of the Tree |
26fbace8 |
548 | instance stored in the C<parent> slot. |
38e3283b |
549 | |
550 | =item C<REGEXP> |
551 | |
26fbace8 |
552 | The regexp option works very similar to the ARRAY option, except that it builds |
553 | the list of methods for you. It starts by collecting all possible methods of the |
554 | class being delegated to, then filters that list using the regexp supplied here. |
38e3283b |
555 | |
26fbace8 |
556 | B<NOTE:> An I<isa> option is required when using the regexp option format. This |
557 | is so that we can determine (at compile time) the method list from the class. |
38e3283b |
558 | Without an I<isa> this is just not possible. |
559 | |
c84f324f |
560 | =item C<ROLE> |
561 | |
26fbace8 |
562 | With the role option, you specify the name of a role whose "interface" then |
563 | becomes the list of methods to handle. The "interface" can be defined as; the |
564 | methods of the role and any required methods of the role. It should be noted |
565 | that this does B<not> include any method modifiers or generated attribute |
c84f324f |
566 | methods (which is consistent with role composition). |
567 | |
38e3283b |
568 | =item C<CODE> |
569 | |
1cd45431 |
570 | This is the option to use when you really want to do something funky. You should |
571 | only use it if you really know what you are doing, as it involves manual |
572 | metaclass twiddling. |
38e3283b |
573 | |
1cd45431 |
574 | This takes a code reference, which should expect two arguments. The first is the |
575 | attribute meta-object this I<handles> is attached to. The second is the |
576 | metaclass of the class being delegated to. It expects you to return a hash (not |
26fbace8 |
577 | a HASH ref) of the methods you want mapped. |
38e3283b |
578 | |
579 | =back |
2c0cbef7 |
580 | |
004222dc |
581 | =item I<metaclass =E<gt> $metaclass_name> |
582 | |
583 | This tells the class to use a custom attribute metaclass for this particular |
584 | attribute. Custom attribute metaclasses are useful for extending the |
585 | capabilities of the I<has> keyword: they are the simplest way to extend the MOP, |
586 | but they are still a fairly advanced topic and too much to cover here, see |
5cfe3805 |
587 | L<Moose::Cookbook::Meta::Recipe1> for more information. |
004222dc |
588 | |
589 | The default behavior here is to just load C<$metaclass_name>; however, we also |
590 | have a way to alias to a shorter name. This will first look to see if |
591 | B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose |
592 | will then check to see if that has the method C<register_implementation>, which |
593 | should return the actual name of the custom attribute metaclass. If there is no |
594 | C<register_implementation> method, it will fall back to using |
595 | B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name. |
596 | |
597 | =item I<traits =E<gt> [ @role_names ]> |
598 | |
599 | This tells Moose to take the list of C<@role_names> and apply them to the |
600 | attribute meta-object. This is very similar to the I<metaclass> option, but |
54f2996d |
601 | allows you to use more than one extension at a time. |
004222dc |
602 | |
54f2996d |
603 | See L<TRAIT NAME RESOLUTION> for details on how a trait name is |
604 | resolved to a class name. |
605 | |
606 | Also see L<Moose::Cookbook::Meta::Recipe3> for a metaclass trait |
607 | example. |
004222dc |
608 | |
6ba6d68c |
609 | =back |
610 | |
cd7eeaf5 |
611 | =item B<has +$name =E<gt> %options> |
612 | |
26fbace8 |
613 | This is variation on the normal attibute creator C<has> which allows you to |
8d62bf6d |
614 | clone and extend an attribute from a superclass or from a role. Here is an |
615 | example of the superclass usage: |
cd7eeaf5 |
616 | |
617 | package Foo; |
618 | use Moose; |
26fbace8 |
619 | |
cd7eeaf5 |
620 | has 'message' => ( |
26fbace8 |
621 | is => 'rw', |
cd7eeaf5 |
622 | isa => 'Str', |
623 | default => 'Hello, I am a Foo' |
624 | ); |
26fbace8 |
625 | |
cd7eeaf5 |
626 | package My::Foo; |
627 | use Moose; |
26fbace8 |
628 | |
cd7eeaf5 |
629 | extends 'Foo'; |
26fbace8 |
630 | |
cd7eeaf5 |
631 | has '+message' => (default => 'Hello I am My::Foo'); |
632 | |
1cd45431 |
633 | What is happening here is that B<My::Foo> is cloning the C<message> attribute |
634 | from its parent class B<Foo>, retaining the C<is =E<gt> 'rw'> and C<isa =E<gt> |
635 | 'Str'> characteristics, but changing the value in C<default>. |
cd7eeaf5 |
636 | |
8d62bf6d |
637 | Here is another example, but within the context of a role: |
638 | |
639 | package Foo::Role; |
640 | use Moose::Role; |
986d175a |
641 | |
8d62bf6d |
642 | has 'message' => ( |
643 | is => 'rw', |
644 | isa => 'Str', |
645 | default => 'Hello, I am a Foo' |
646 | ); |
986d175a |
647 | |
8d62bf6d |
648 | package My::Foo; |
649 | use Moose; |
986d175a |
650 | |
8d62bf6d |
651 | with 'Foo::Role'; |
986d175a |
652 | |
8d62bf6d |
653 | has '+message' => (default => 'Hello I am My::Foo'); |
654 | |
655 | In this case, we are basically taking the attribute which the role supplied |
4032c9bb |
656 | and altering it within the bounds of this feature. |
8d62bf6d |
657 | |
4032c9bb |
658 | Aside from where the attributes come from (one from superclass, the other |
659 | from a role), this feature works exactly the same. This feature is restricted |
660 | somewhat, so as to try and force at least I<some> sanity into it. You are only |
661 | allowed to change the following attributes: |
cd7eeaf5 |
662 | |
663 | =over 4 |
664 | |
26fbace8 |
665 | =item I<default> |
cd7eeaf5 |
666 | |
667 | Change the default value of an attribute. |
668 | |
26fbace8 |
669 | =item I<coerce> |
cd7eeaf5 |
670 | |
671 | Change whether the attribute attempts to coerce a value passed to it. |
672 | |
26fbace8 |
673 | =item I<required> |
cd7eeaf5 |
674 | |
675 | Change if the attribute is required to have a value. |
676 | |
677 | =item I<documentation> |
678 | |
679 | Change the documentation string associated with the attribute. |
680 | |
83cc9094 |
681 | =item I<lazy> |
682 | |
683 | Change if the attribute lazily initializes the slot. |
684 | |
cd7eeaf5 |
685 | =item I<isa> |
686 | |
aed87761 |
687 | You I<are> allowed to change the type without restriction. |
688 | |
689 | It is recommended that you use this freedom with caution. We used to |
690 | only allow for extension only if the type was a subtype of the parent's |
691 | type, but we felt that was too restrictive and is better left as a |
692 | policy descision. |
cd7eeaf5 |
693 | |
83cc9094 |
694 | =item I<handles> |
695 | |
26fbace8 |
696 | You are allowed to B<add> a new C<handles> definition, but you are B<not> |
697 | allowed to I<change> one. |
83cc9094 |
698 | |
8d62bf6d |
699 | =item I<builder> |
700 | |
701 | You are allowed to B<add> a new C<builder> definition, but you are B<not> |
702 | allowed to I<change> one. |
703 | |
13284479 |
704 | =item I<metaclass> |
705 | |
706 | You are allowed to B<add> a new C<metaclass> definition, but you are |
707 | B<not> allowed to I<change> one. |
708 | |
709 | =item I<traits> |
710 | |
711 | You are allowed to B<add> additional traits to the C<traits> definition. |
712 | These traits will be composed into the attribute, but pre-existing traits |
713 | B<are not> overridden, or removed. |
714 | |
cd7eeaf5 |
715 | =back |
716 | |
076c81ed |
717 | =item B<before $name|@names =E<gt> sub { ... }> |
6ba6d68c |
718 | |
076c81ed |
719 | =item B<after $name|@names =E<gt> sub { ... }> |
6ba6d68c |
720 | |
076c81ed |
721 | =item B<around $name|@names =E<gt> sub { ... }> |
6ba6d68c |
722 | |
d8af92ae |
723 | This three items are syntactic sugar for the before, after, and around method |
724 | modifier features that L<Class::MOP> provides. More information on these may be |
725 | found in the L<Class::MOP::Class documentation|Class::MOP::Class/"Method |
726 | Modifiers"> for now. |
6ba6d68c |
727 | |
159da176 |
728 | =item B<super> |
729 | |
26fbace8 |
730 | The keyword C<super> is a no-op when called outside of an C<override> method. In |
731 | the context of an C<override> method, it will call the next most appropriate |
159da176 |
732 | superclass method with the same arguments as the original method. |
733 | |
734 | =item B<override ($name, &sub)> |
735 | |
26fbace8 |
736 | An C<override> method is a way of explicitly saying "I am overriding this |
737 | method from my superclass". You can call C<super> within this method, and |
738 | it will work as expected. The same thing I<can> be accomplished with a normal |
739 | method call and the C<SUPER::> pseudo-package; it is really your choice. |
159da176 |
740 | |
741 | =item B<inner> |
742 | |
26fbace8 |
743 | The keyword C<inner>, much like C<super>, is a no-op outside of the context of |
744 | an C<augment> method. You can think of C<inner> as being the inverse of |
68efb014 |
745 | C<super>; the details of how C<inner> and C<augment> work is best described in |
5cfe3805 |
746 | the L<Moose::Cookbook::Basics::Recipe6>. |
159da176 |
747 | |
748 | =item B<augment ($name, &sub)> |
749 | |
26fbace8 |
750 | An C<augment> method, is a way of explicitly saying "I am augmenting this |
751 | method from my superclass". Once again, the details of how C<inner> and |
5cfe3805 |
752 | C<augment> work is best described in the L<Moose::Cookbook::Basics::Recipe6>. |
159da176 |
753 | |
6ba6d68c |
754 | =item B<confess> |
755 | |
68efb014 |
756 | This is the C<Carp::confess> function, and exported here because I use it |
004222dc |
757 | all the time. |
6ba6d68c |
758 | |
759 | =item B<blessed> |
760 | |
1cd45431 |
761 | This is the C<Scalar::Util::blessed> function, it is exported here because I |
26fbace8 |
762 | use it all the time. It is highly recommended that this is used instead of |
6ba6d68c |
763 | C<ref> anywhere you need to test for an object's class name. |
764 | |
765 | =back |
766 | |
54f2996d |
767 | =head1 METACLASS TRAITS |
768 | |
769 | When you use Moose, you can also specify traits which will be applied |
770 | to your metaclass: |
771 | |
772 | use Moose -traits => 'My::Trait'; |
773 | |
774 | This is very similar to the attribute traits feature. When you do |
775 | this, your class's C<meta> object will have the specified traits |
776 | applied to it. See L<TRAIT NAME RESOLUTION> for more details. |
777 | |
778 | =head1 TRAIT NAME RESOLUTION |
779 | |
780 | By default, when given a trait name, Moose simply tries to load a |
781 | class of the same name. If such a class does not exist, it then looks |
782 | for for a class matching |
783 | B<Moose::Meta::$type::Custom::Trait::$trait_name>. The C<$type> |
784 | variable here will be one of B<Attribute> or B<Class>, depending on |
785 | what the trait is being applied to. |
786 | |
787 | If a class with this long name exists, Moose checks to see if it has |
788 | the method C<register_implementation>. This method is expected to |
789 | return the I<real> class name of the trait. If there is no |
790 | C<register_implementation> method, it will fall back to using |
791 | B<Moose::Meta::$type::Custom::Trait::$trait> as the trait name. |
792 | |
793 | If all this is confusing, take a look at |
794 | L<Moose::Cookbook::Meta::Recipe3>, which demonstrates how to create an |
795 | attribute trait. |
796 | |
1cd45431 |
797 | =head1 UNIMPORTING FUNCTIONS |
31f8ec72 |
798 | |
799 | =head2 B<unimport> |
800 | |
1cd45431 |
801 | Moose offers a way to remove the keywords it exports, through the C<unimport> |
31f8ec72 |
802 | method. You simply have to say C<no Moose> at the bottom of your code for this |
803 | to work. Here is an example: |
804 | |
805 | package Person; |
806 | use Moose; |
807 | |
808 | has 'first_name' => (is => 'rw', isa => 'Str'); |
809 | has 'last_name' => (is => 'rw', isa => 'Str'); |
26fbace8 |
810 | |
811 | sub full_name { |
31f8ec72 |
812 | my $self = shift; |
26fbace8 |
813 | $self->first_name . ' ' . $self->last_name |
31f8ec72 |
814 | } |
26fbace8 |
815 | |
816 | no Moose; # keywords are removed from the Person package |
31f8ec72 |
817 | |
9bcfbab1 |
818 | =head1 EXTENDING AND EMBEDDING MOOSE |
819 | |
5e86efbe |
820 | To learn more about extending Moose, we recommend checking out the |
821 | "Extending" recipes in the L<Moose::Cookbook>, starting with |
822 | L<Moose::Cookbook::Extending::Recipe1>, which provides an overview of |
823 | all the different ways you might extend Moose. |
554b7648 |
824 | |
825 | =head2 B<< Moose->init_meta(for_class => $class, base_class => $baseclass, metaclass => $metaclass) >> |
9bcfbab1 |
826 | |
554b7648 |
827 | The C<init_meta> method sets up the metaclass object for the class |
b143539e |
828 | specified by C<for_class>. This method injects a a C<meta> accessor |
829 | into the class so you can get at this object. It also sets the class's |
554b7648 |
830 | superclass to C<base_class>, with L<Moose::Object> as the default. |
9bcfbab1 |
831 | |
554b7648 |
832 | You can specify an alternate metaclass with the C<metaclass> parameter. |
26fbace8 |
833 | |
80837fe1 |
834 | For more detail on this topic, see L<Moose::Cookbook::Extending::Recipe2>. |
835 | |
554b7648 |
836 | This method used to be documented as a function which accepted |
837 | positional parameters. This calling style will still work for |
4a66a4b3 |
838 | backwards compatibility, but is deprecated. |
554b7648 |
839 | |
840 | =head2 B<import> |
841 | |
842 | Moose's C<import> method supports the L<Sub::Exporter> form of C<{into =E<gt> $pkg}> |
843 | and C<{into_level =E<gt> 1}>. |
844 | |
845 | B<NOTE>: Doing this is more or less deprecated. Use L<Moose::Exporter> |
846 | instead, which lets you stack multiple C<Moose.pm>-alike modules |
847 | sanely. It handles getting the exported functions into the right place |
848 | for you. |
849 | |
4c0b3599 |
850 | =head2 throw_error |
851 | |
852 | An alias for C<confess>, used by internally by Moose. |
853 | |
05d9eaf6 |
854 | =head1 CAVEATS |
855 | |
856 | =over 4 |
857 | |
858 | =item * |
859 | |
1cd45431 |
860 | It should be noted that C<super> and C<inner> B<cannot> be used in the same |
861 | method. However, they may be combined within the same class hierarchy; see |
862 | F<t/014_override_augment_inner_super.t> for an example. |
05d9eaf6 |
863 | |
26fbace8 |
864 | The reason for this is that C<super> is only valid within a method |
865 | with the C<override> modifier, and C<inner> will never be valid within an |
866 | C<override> method. In fact, C<augment> will skip over any C<override> methods |
68efb014 |
867 | when searching for its appropriate C<inner>. |
05d9eaf6 |
868 | |
1cd45431 |
869 | This might seem like a restriction, but I am of the opinion that keeping these |
870 | two features separate (yet interoperable) actually makes them easy to use, since |
871 | their behavior is then easier to predict. Time will tell whether I am right or |
c84f324f |
872 | not (UPDATE: so far so good). |
05d9eaf6 |
873 | |
9b9da6f1 |
874 | =back |
875 | |
5569c072 |
876 | =head1 ACKNOWLEDGEMENTS |
877 | |
878 | =over 4 |
879 | |
54c189df |
880 | =item I blame Sam Vilain for introducing me to the insanity that is meta-models. |
5569c072 |
881 | |
54c189df |
882 | =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6. |
5569c072 |
883 | |
26fbace8 |
884 | =item Without Yuval "nothingmuch" Kogman this module would not be possible, |
54c189df |
885 | and it certainly wouldn't have this name ;P |
5569c072 |
886 | |
26fbace8 |
887 | =item The basis of the TypeContraints module was Rob Kinyon's idea |
5569c072 |
888 | originally, I just ran with it. |
889 | |
638585e1 |
890 | =item Thanks to mst & chansen and the whole #moose posse for all the |
c84f324f |
891 | early ideas/feature-requests/encouragement/bug-finding. |
d46a48f3 |
892 | |
68efb014 |
893 | =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes. |
894 | |
5569c072 |
895 | =back |
896 | |
e90c03d0 |
897 | =head1 SEE ALSO |
898 | |
899 | =over 4 |
900 | |
c84f324f |
901 | =item L<http://www.iinteractive.com/moose> |
902 | |
903 | This is the official web home of Moose, it contains links to our public SVN repo |
26fbace8 |
904 | as well as links to a number of talks and articles on Moose and Moose related |
905 | technologies. |
c84f324f |
906 | |
196064ab |
907 | =item L<Moose::Cookbook> - How to cook a Moose |
908 | |
909 | =item The Moose is flying, a tutorial by Randal Schwartz |
910 | |
911 | Part 1 - L<http://www.stonehenge.com/merlyn/LinuxMag/col94.html> |
912 | |
913 | Part 2 - L<http://www.stonehenge.com/merlyn/LinuxMag/col95.html> |
914 | |
6ba6d68c |
915 | =item L<Class::MOP> documentation |
916 | |
917 | =item The #moose channel on irc.perl.org |
918 | |
e67a0fca |
919 | =item The Moose mailing list - moose@perl.org |
920 | |
9e0361e1 |
921 | =item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/moose> |
c84f324f |
922 | |
12aed9a0 |
923 | =item Several Moose extension modules in the C<MooseX::> namespace. |
924 | |
925 | See L<http://search.cpan.org/search?query=MooseX::> for extensions. |
28669f89 |
926 | |
c84f324f |
927 | =back |
928 | |
004222dc |
929 | =head2 Books |
930 | |
931 | =over 4 |
932 | |
933 | =item The Art of the MetaObject Protocol |
934 | |
935 | I mention this in the L<Class::MOP> docs too, this book was critical in |
936 | the development of both modules and is highly recommended. |
937 | |
938 | =back |
939 | |
26fbace8 |
940 | =head2 Papers |
c84f324f |
941 | |
942 | =over 4 |
e90c03d0 |
943 | |
159da176 |
944 | =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf> |
945 | |
26fbace8 |
946 | This paper (suggested by lbr on #moose) was what lead to the implementation |
947 | of the C<super>/C<override> and C<inner>/C<augment> features. If you really |
1cd45431 |
948 | want to understand them, I suggest you read this. |
159da176 |
949 | |
e90c03d0 |
950 | =back |
951 | |
fcd84ca9 |
952 | =head1 BUGS |
953 | |
26fbace8 |
954 | All complex software has bugs lurking in it, and this module is no |
fcd84ca9 |
955 | exception. If you find a bug please either email me, or add the bug |
956 | to cpan-RT. |
957 | |
47b19570 |
958 | =head1 FEATURE REQUESTS |
959 | |
960 | We are very strict about what features we add to the Moose core, especially |
961 | the user-visible features. Instead we have made sure that the underlying |
962 | meta-system of Moose is as extensible as possible so that you can add your |
963 | own features easily. That said, occasionally there is a feature needed in the |
964 | meta-system to support your planned extension, in which case you should |
965 | either email the mailing list or join us on irc at #moose to discuss. |
966 | |
fcd84ca9 |
967 | =head1 AUTHOR |
968 | |
969 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
970 | |
9af1d28b |
971 | B<with contributions from:> |
db1ab48d |
972 | |
9af1d28b |
973 | Aankhen |
974 | |
975 | Adam (Alias) Kennedy |
976 | |
977 | Anders (Debolaz) Nor Berle |
978 | |
5868294f |
979 | Nathan (kolibre) Gray |
980 | |
9af1d28b |
981 | Christian (chansen) Hansen |
982 | |
e7f8d0c2 |
983 | Hans Dieter (confound) Pearcey |
984 | |
9af1d28b |
985 | Eric (ewilhelm) Wilhelm |
986 | |
987 | Guillermo (groditi) Roditi |
988 | |
989 | Jess (castaway) Robinson |
990 | |
991 | Matt (mst) Trout |
992 | |
993 | Robert (phaylon) Sedlacek |
994 | |
995 | Robert (rlb3) Boone |
996 | |
997 | Scott (konobi) McWhirter |
998 | |
f44ae52f |
999 | Shlomi (rindolf) Fish |
1000 | |
9af1d28b |
1001 | Yuval (nothingmuch) Kogman |
1002 | |
cbe25729 |
1003 | Chris (perigrin) Prather |
1004 | |
68b6146c |
1005 | Wallace (wreis) Reis |
1006 | |
e46f5cc2 |
1007 | Jonathan (jrockway) Rockway |
1008 | |
abfdc2b4 |
1009 | Dave (autarch) Rolsky |
1010 | |
3ccdc84a |
1011 | Piotr (dexter) Roszatycki |
1012 | |
26fbace8 |
1013 | Sam (mugwump) Vilain |
f1917f58 |
1014 | |
ac211120 |
1015 | Shawn (sartak) Moore |
1016 | |
9af1d28b |
1017 | ... and many other #moose folks |
98aae381 |
1018 | |
fcd84ca9 |
1019 | =head1 COPYRIGHT AND LICENSE |
1020 | |
778db3ac |
1021 | Copyright 2006-2008 by Infinity Interactive, Inc. |
fcd84ca9 |
1022 | |
1023 | L<http://www.iinteractive.com> |
1024 | |
1025 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
1026 | it under the same terms as Perl itself. |
fcd84ca9 |
1027 | |
ddd0ec20 |
1028 | =cut |