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 |
0635500e |
64 | my $meta = Moose::Meta::Class->initialize($class); |
65 | $meta->_fix_metaclass_incompatibility(@supers); |
5bd4db9b |
66 | $meta->superclasses(@supers); |
67 | } |
a3c7e2fe |
68 | |
5bd4db9b |
69 | sub with { |
97a93056 |
70 | my $class = shift; |
aedcb7d9 |
71 | Moose::Util::apply_all_roles(Class::MOP::Class->initialize($class), @_); |
5bd4db9b |
72 | } |
9bcfbab1 |
73 | |
5bd4db9b |
74 | sub has { |
97a93056 |
75 | my $class = shift; |
5bd4db9b |
76 | my $name = shift; |
77 | croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1; |
78 | my %options = @_; |
79 | my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; |
aedcb7d9 |
80 | Class::MOP::Class->initialize($class)->add_attribute( $_, %options ) for @$attrs; |
5bd4db9b |
81 | } |
9bcfbab1 |
82 | |
5bd4db9b |
83 | sub before { |
97a93056 |
84 | my $class = shift; |
5bd4db9b |
85 | Moose::Util::add_method_modifier($class, 'before', \@_); |
86 | } |
87 | |
88 | sub after { |
97a93056 |
89 | my $class = shift; |
5bd4db9b |
90 | Moose::Util::add_method_modifier($class, 'after', \@_); |
91 | } |
92 | |
93 | sub around { |
97a93056 |
94 | my $class = shift; |
5bd4db9b |
95 | Moose::Util::add_method_modifier($class, 'around', \@_); |
96 | } |
97 | |
98 | sub super { |
99 | return unless our $SUPER_BODY; $SUPER_BODY->(our @SUPER_ARGS); |
100 | } |
9bcfbab1 |
101 | |
5bd4db9b |
102 | sub override { |
97a93056 |
103 | my $class = shift; |
5bd4db9b |
104 | my ( $name, $method ) = @_; |
aedcb7d9 |
105 | Class::MOP::Class->initialize($class)->add_override_method_modifier( $name => $method ); |
5bd4db9b |
106 | } |
9bcfbab1 |
107 | |
5bd4db9b |
108 | sub inner { |
109 | my $pkg = caller(); |
110 | our ( %INNER_BODY, %INNER_ARGS ); |
111 | |
112 | if ( my $body = $INNER_BODY{$pkg} ) { |
113 | my @args = @{ $INNER_ARGS{$pkg} }; |
114 | local $INNER_ARGS{$pkg}; |
115 | local $INNER_BODY{$pkg}; |
116 | return $body->(@args); |
117 | } else { |
118 | return; |
ce265cc3 |
119 | } |
5bd4db9b |
120 | } |
9bcfbab1 |
121 | |
5bd4db9b |
122 | sub augment { |
97a93056 |
123 | my $class = shift; |
5bd4db9b |
124 | my ( $name, $method ) = @_; |
aedcb7d9 |
125 | Class::MOP::Class->initialize($class)->add_augment_method_modifier( $name => $method ); |
ce265cc3 |
126 | } |
9bcfbab1 |
127 | |
5bd4db9b |
128 | sub make_immutable { |
97a93056 |
129 | my $class = shift; |
5bd4db9b |
130 | cluck "The make_immutable keyword has been deprecated, " . |
131 | "please go back to __PACKAGE__->meta->make_immutable\n"; |
aedcb7d9 |
132 | Class::MOP::Class->initialize($class)->make_immutable(@_); |
5bd4db9b |
133 | } |
9bcfbab1 |
134 | |
aedcb7d9 |
135 | Moose::Exporter->setup_import_methods( |
97a93056 |
136 | with_caller => [ |
137 | qw( extends with has before after around override augment make_immutable ) |
138 | ], |
139 | as_is => [ |
140 | qw( super inner ), |
5bd4db9b |
141 | \&Carp::confess, |
142 | \&Scalar::Util::blessed, |
143 | ], |
144 | ); |
145 | |
cc841c0e |
146 | sub init_meta { |
085fba61 |
147 | # This used to be called as a function. This hack preserves |
148 | # backwards compatibility. |
149 | if ( $_[0] ne __PACKAGE__ ) { |
150 | return __PACKAGE__->init_meta( |
151 | for_class => $_[0], |
152 | base_class => $_[1], |
153 | metaclass => $_[2], |
154 | ); |
155 | } |
7c4676ef |
156 | |
0338a411 |
157 | shift; |
158 | my %args = @_; |
159 | |
160 | my $class = $args{for_class} |
c245d69b |
161 | or Moose->throw_error("Cannot call init_meta without specifying a for_class"); |
085fba61 |
162 | my $base_class = $args{base_class} || 'Moose::Object'; |
163 | my $metaclass = $args{metaclass} || 'Moose::Meta::Class'; |
cc841c0e |
164 | |
c245d69b |
165 | Moose->throw_error("The Metaclass $metaclass must be a subclass of Moose::Meta::Class.") |
cc841c0e |
166 | unless $metaclass->isa('Moose::Meta::Class'); |
167 | |
168 | # make a subtype for each Moose class |
169 | class_type($class) |
170 | unless find_type_constraint($class); |
171 | |
172 | my $meta; |
50d5df60 |
173 | |
174 | if ( $meta = Class::MOP::get_metaclass_by_name($class) ) { |
175 | unless ( $meta->isa("Moose::Meta::Class") ) { |
c245d69b |
176 | Moose->throw_error("$class already has a metaclass, but it does not inherit $metaclass ($meta)"); |
50d5df60 |
177 | } |
178 | } else { |
179 | # no metaclass, no 'meta' method |
180 | |
181 | # now we check whether our ancestors have metaclass, and if so borrow that |
182 | my ( undef, @isa ) = @{ $class->mro::get_linear_isa }; |
183 | |
184 | foreach my $ancestor ( @isa ) { |
185 | my $ancestor_meta = Class::MOP::get_metaclass_by_name($ancestor) || next; |
186 | |
187 | my $ancestor_meta_class = ($ancestor_meta->is_immutable |
188 | ? $ancestor_meta->get_mutable_metaclass_name |
189 | : ref($ancestor_meta)); |
190 | |
191 | # if we have an ancestor metaclass that inherits $metaclass, we use |
41419b9e |
192 | # that. This is like _fix_metaclass_incompatibility, but we can do it now. |
50d5df60 |
193 | |
194 | # the case of having an ancestry is not very common, but arises in |
195 | # e.g. Reaction |
196 | unless ( $metaclass->isa( $ancestor_meta_class ) ) { |
197 | if ( $ancestor_meta_class->isa($metaclass) ) { |
198 | $metaclass = $ancestor_meta_class; |
199 | } |
200 | } |
201 | } |
202 | |
203 | $meta = $metaclass->initialize($class); |
204 | } |
205 | |
cc841c0e |
206 | if ( $class->can('meta') ) { |
50d5df60 |
207 | # check 'meta' method |
208 | |
209 | # it may be inherited |
210 | |
cc841c0e |
211 | # NOTE: |
212 | # this is the case where the metaclass pragma |
213 | # was used before the 'use Moose' statement to |
214 | # override a specific class |
50d5df60 |
215 | my $method_meta = $class->meta; |
216 | |
217 | ( blessed($method_meta) && $method_meta->isa('Moose::Meta::Class') ) |
c245d69b |
218 | || Moose->throw_error("$class already has a &meta function, but it does not return a Moose::Meta::Class ($meta)"); |
50d5df60 |
219 | |
220 | $meta = $method_meta; |
cc841c0e |
221 | } |
50d5df60 |
222 | |
223 | unless ( $meta->has_method("meta") ) { # don't overwrite |
224 | # also check for inherited non moose 'meta' method? |
225 | # FIXME also skip this if the user requested by passing an option |
cc841c0e |
226 | $meta->add_method( |
227 | 'meta' => sub { |
228 | # re-initialize so it inherits properly |
50d5df60 |
229 | $metaclass->initialize( ref($_[0]) || $_[0] ); |
cc841c0e |
230 | } |
231 | ); |
232 | } |
233 | |
234 | # make sure they inherit from Moose::Object |
235 | $meta->superclasses($base_class) |
236 | unless $meta->superclasses(); |
237 | |
238 | return $meta; |
239 | } |
240 | |
085fba61 |
241 | # This may be used in some older MooseX extensions. |
242 | sub _get_caller { |
243 | goto &Moose::Exporter::_get_caller; |
244 | } |
245 | |
8ecb1fa0 |
246 | ## make 'em all immutable |
247 | |
248 | $_->meta->make_immutable( |
0779da92 |
249 | inline_constructor => 1, |
250 | constructor_name => "_new", |
77a18c28 |
251 | inline_accessors => 1, # these are Class::MOP accessors, so they need inlining |
9bcfbab1 |
252 | ) |
0779da92 |
253 | for (qw( |
254 | Moose::Meta::Attribute |
255 | Moose::Meta::Class |
256 | Moose::Meta::Instance |
257 | |
258 | Moose::Meta::TypeConstraint |
259 | Moose::Meta::TypeConstraint::Union |
260 | Moose::Meta::TypeConstraint::Parameterized |
9ad786af |
261 | Moose::Meta::TypeConstraint::Parameterizable |
0779da92 |
262 | Moose::Meta::TypeConstraint::Enum |
263 | Moose::Meta::TypeConstraint::Class |
264 | Moose::Meta::TypeConstraint::Role |
265 | Moose::Meta::TypeConstraint::Registry |
266 | Moose::Meta::TypeCoercion |
267 | Moose::Meta::TypeCoercion::Union |
268 | |
269 | Moose::Meta::Method |
270 | Moose::Meta::Method::Accessor |
271 | Moose::Meta::Method::Constructor |
272 | Moose::Meta::Method::Destructor |
273 | Moose::Meta::Method::Overriden |
274 | Moose::Meta::Method::Augmented |
275 | |
276 | Moose::Meta::Role |
277 | Moose::Meta::Role::Method |
278 | Moose::Meta::Role::Method::Required |
279 | |
280 | Moose::Meta::Role::Composite |
281 | |
282 | Moose::Meta::Role::Application |
283 | Moose::Meta::Role::Application::RoleSummation |
284 | Moose::Meta::Role::Application::ToClass |
285 | Moose::Meta::Role::Application::ToRole |
286 | Moose::Meta::Role::Application::ToInstance |
0779da92 |
287 | )); |
8ecb1fa0 |
288 | |
fcd84ca9 |
289 | 1; |
290 | |
291 | __END__ |
292 | |
293 | =pod |
294 | |
295 | =head1 NAME |
296 | |
8bdc7f13 |
297 | Moose - A postmodern object system for Perl 5 |
fcd84ca9 |
298 | |
299 | =head1 SYNOPSIS |
e522431d |
300 | |
301 | package Point; |
1cd45431 |
302 | use Moose; # automatically turns on strict and warnings |
26fbace8 |
303 | |
43d599e5 |
304 | has 'x' => (is => 'rw', isa => 'Int'); |
305 | has 'y' => (is => 'rw', isa => 'Int'); |
26fbace8 |
306 | |
e522431d |
307 | sub clear { |
308 | my $self = shift; |
309 | $self->x(0); |
26fbace8 |
310 | $self->y(0); |
e522431d |
311 | } |
26fbace8 |
312 | |
e522431d |
313 | package Point3D; |
314 | use Moose; |
26fbace8 |
315 | |
e522431d |
316 | extends 'Point'; |
26fbace8 |
317 | |
43d599e5 |
318 | has 'z' => (is => 'rw', isa => 'Int'); |
26fbace8 |
319 | |
e522431d |
320 | after 'clear' => sub { |
321 | my $self = shift; |
43d599e5 |
322 | $self->z(0); |
26fbace8 |
323 | }; |
2c0cbef7 |
324 | |
fcd84ca9 |
325 | =head1 DESCRIPTION |
326 | |
26fbace8 |
327 | Moose is an extension of the Perl 5 object system. |
e522431d |
328 | |
9b9da6f1 |
329 | The main goal of Moose is to make Perl 5 Object Oriented programming |
330 | easier, more consistent and less tedious. With Moose you can to think |
6f894f30 |
331 | more about what you want to do and less about the mechanics of OOP. |
fcd84ca9 |
332 | |
6f894f30 |
333 | Additionally, Moose is built on top of L<Class::MOP>, which is a |
334 | metaclass system for Perl 5. This means that Moose not only makes |
335 | building normal Perl 5 objects better, but it provides the power of |
336 | metaclass programming as well. |
8bdc7f13 |
337 | |
f5909dca |
338 | =head2 New to Moose? |
339 | |
6f894f30 |
340 | If you're new to Moose, the best place to start is the L<Moose::Intro> |
341 | docs, followed by the L<Moose::Cookbook>. The intro will show you what |
342 | Moose is, and how it makes Perl 5 OO better. |
343 | |
344 | The cookbook recipes on Moose basics will get you up to speed with |
345 | many of Moose's features quickly. Once you have an idea of what Moose |
346 | can do, you can use the API documentation to get more detail on |
347 | features which interest you. |
f5909dca |
348 | |
28669f89 |
349 | =head2 Moose Extensions |
350 | |
12aed9a0 |
351 | The C<MooseX::> namespace is the official place to find Moose extensions. |
352 | These extensions can be found on the CPAN. The easiest way to find them |
353 | is to search for them (L<http://search.cpan.org/search?query=MooseX::>), |
354 | or to examine L<Task::Moose> which aims to keep an up-to-date, easily |
355 | installable list of Moose extensions. |
28669f89 |
356 | |
6ba6d68c |
357 | =head1 BUILDING CLASSES WITH MOOSE |
358 | |
68efb014 |
359 | Moose makes every attempt to provide as much convenience as possible during |
360 | class construction/definition, but still stay out of your way if you want it |
361 | to. Here are a few items to note when building classes with Moose. |
6ba6d68c |
362 | |
26fbace8 |
363 | Unless specified with C<extends>, any class which uses Moose will |
6ba6d68c |
364 | inherit from L<Moose::Object>. |
365 | |
1cd45431 |
366 | Moose will also manage all attributes (including inherited ones) that are |
367 | defined with C<has>. And (assuming you call C<new>, which is inherited from |
368 | L<Moose::Object>) this includes properly initializing all instance slots, |
369 | setting defaults where appropriate, and performing any type constraint checking |
370 | or coercion. |
6ba6d68c |
371 | |
004222dc |
372 | =head1 PROVIDED METHODS |
6ba6d68c |
373 | |
004222dc |
374 | Moose provides a number of methods to all your classes, mostly through the |
375 | inheritance of L<Moose::Object>. There is however, one exception. |
6ba6d68c |
376 | |
377 | =over 4 |
378 | |
379 | =item B<meta> |
380 | |
381 | This is a method which provides access to the current class's metaclass. |
382 | |
004222dc |
383 | =back |
384 | |
385 | =head1 EXPORTED FUNCTIONS |
386 | |
387 | Moose will export a number of functions into the class's namespace which |
388 | may then be used to set up the class. These functions all work directly |
389 | on the current class. |
390 | |
391 | =over 4 |
392 | |
6ba6d68c |
393 | =item B<extends (@superclasses)> |
394 | |
395 | This function will set the superclass(es) for the current class. |
396 | |
26fbace8 |
397 | This approach is recommended instead of C<use base>, because C<use base> |
398 | actually C<push>es onto the class's C<@ISA>, whereas C<extends> will |
399 | replace it. This is important to ensure that classes which do not have |
68efb014 |
400 | superclasses still properly inherit from L<Moose::Object>. |
6ba6d68c |
401 | |
43d599e5 |
402 | =item B<with (@roles)> |
e9ec68d6 |
403 | |
004222dc |
404 | This will apply a given set of C<@roles> to the local class. |
e9ec68d6 |
405 | |
cd7eeaf5 |
406 | =item B<has $name =E<gt> %options> |
6ba6d68c |
407 | |
26fbace8 |
408 | This will install an attribute of a given C<$name> into the current class. |
409 | The C<%options> are the same as those provided by |
410 | L<Class::MOP::Attribute>, in addition to the list below which are provided |
43d599e5 |
411 | by Moose (L<Moose::Meta::Attribute> to be more specific): |
6ba6d68c |
412 | |
413 | =over 4 |
414 | |
076c81ed |
415 | =item I<is =E<gt> 'rw'|'ro'> |
6ba6d68c |
416 | |
26fbace8 |
417 | The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read |
418 | only). These will create either a read/write accessor or a read-only |
6ba6d68c |
419 | accessor respectively, using the same name as the C<$name> of the attribute. |
420 | |
1cd45431 |
421 | If you need more control over how your accessors are named, you can use the |
422 | I<reader>, I<writer> and I<accessor> options inherited from |
004222dc |
423 | L<Class::MOP::Attribute>, however if you use those, you won't need the I<is> |
424 | option. |
6ba6d68c |
425 | |
076c81ed |
426 | =item I<isa =E<gt> $type_name> |
6ba6d68c |
427 | |
26fbace8 |
428 | The I<isa> option uses Moose's type constraint facilities to set up runtime |
429 | type checking for this attribute. Moose will perform the checks during class |
430 | construction, and within any accessors. The C<$type_name> argument must be a |
431 | string. The string may be either a class name or a type defined using |
9cca2e9e |
432 | Moose's type definition features. (Refer to L<Moose::Util::TypeConstraints> |
c2a69ef1 |
433 | for information on how to define a new type, and how to retrieve type meta-data). |
6ba6d68c |
434 | |
daea75c9 |
435 | =item I<coerce =E<gt> (1|0)> |
436 | |
26fbace8 |
437 | This will attempt to use coercion with the supplied type constraint to change |
438 | the value passed into any accessors or constructors. You B<must> have supplied |
5cfe3805 |
439 | a type constraint in order for this to work. See L<Moose::Cookbook::Basics::Recipe5> |
1cd45431 |
440 | for an example. |
daea75c9 |
441 | |
442 | =item I<does =E<gt> $role_name> |
443 | |
26fbace8 |
444 | This will accept the name of a role which the value stored in this attribute |
daea75c9 |
445 | is expected to have consumed. |
446 | |
447 | =item I<required =E<gt> (1|0)> |
448 | |
26fbace8 |
449 | This marks the attribute as being required. This means a I<defined> value must be |
450 | supplied during class construction, and the attribute may never be set to |
451 | C<undef> with an accessor. |
daea75c9 |
452 | |
453 | =item I<weak_ref =E<gt> (1|0)> |
454 | |
68efb014 |
455 | This will tell the class to store the value of this attribute as a weakened |
456 | reference. If an attribute is a weakened reference, it B<cannot> also be |
457 | coerced. |
daea75c9 |
458 | |
459 | =item I<lazy =E<gt> (1|0)> |
460 | |
26fbace8 |
461 | This will tell the class to not create this slot until absolutely necessary. |
daea75c9 |
462 | If an attribute is marked as lazy it B<must> have a default supplied. |
463 | |
9e93dd19 |
464 | =item I<auto_deref =E<gt> (1|0)> |
465 | |
26fbace8 |
466 | This tells the accessor whether to automatically dereference the value returned. |
1cd45431 |
467 | This is only legal if your C<isa> option is either C<ArrayRef> or C<HashRef>. |
9e93dd19 |
468 | |
65e14c86 |
469 | =item I<trigger =E<gt> $code> |
470 | |
471 | The I<trigger> option is a CODE reference which will be called after the value of |
472 | the attribute is set. The CODE ref will be passed the instance itself, the |
473 | updated value and the attribute meta-object (this is for more advanced fiddling |
474 | and can typically be ignored). You B<cannot> have a trigger on a read-only |
475 | attribute. |
daea75c9 |
476 | |
c84f324f |
477 | =item I<handles =E<gt> ARRAY | HASH | REGEXP | ROLE | CODE> |
2c0cbef7 |
478 | |
26fbace8 |
479 | The I<handles> option provides Moose classes with automated delegation features. |
480 | This is a pretty complex and powerful option. It accepts many different option |
481 | formats, each with its own benefits and drawbacks. |
38e3283b |
482 | |
1cd45431 |
483 | B<NOTE:> The class being delegated to does not need to be a Moose based class, |
484 | which is why this feature is especially useful when wrapping non-Moose classes. |
38e3283b |
485 | |
1cd45431 |
486 | All I<handles> option formats share the following traits: |
38e3283b |
487 | |
1cd45431 |
488 | You cannot override a locally defined method with a delegated method; an |
489 | exception will be thrown if you try. That is to say, if you define C<foo> in |
490 | your class, you cannot override it with a delegated C<foo>. This is almost never |
491 | something you would want to do, and if it is, you should do it by hand and not |
492 | use Moose. |
38e3283b |
493 | |
1cd45431 |
494 | You cannot override any of the methods found in Moose::Object, or the C<BUILD> |
495 | and C<DEMOLISH> methods. These will not throw an exception, but will silently |
496 | move on to the next method in the list. My reasoning for this is that you would |
497 | almost never want to do this, since it usually breaks your class. As with |
498 | overriding locally defined methods, if you do want to do this, you should do it |
499 | manually, not with Moose. |
38e3283b |
500 | |
f3c4e20e |
501 | You do not I<need> to have a reader (or accessor) for the attribute in order |
502 | to delegate to it. Moose will create a means of accessing the value for you, |
503 | however this will be several times B<less> efficient then if you had given |
504 | the attribute a reader (or accessor) to use. |
505 | |
38e3283b |
506 | Below is the documentation for each option format: |
507 | |
508 | =over 4 |
509 | |
510 | =item C<ARRAY> |
511 | |
26fbace8 |
512 | This is the most common usage for I<handles>. You basically pass a list of |
513 | method names to be delegated, and Moose will install a delegation method |
1cd45431 |
514 | for each one. |
38e3283b |
515 | |
516 | =item C<HASH> |
517 | |
26fbace8 |
518 | This is the second most common usage for I<handles>. Instead of a list of |
519 | method names, you pass a HASH ref where each key is the method name you |
520 | want installed locally, and its value is the name of the original method |
521 | in the class being delegated to. |
fd595040 |
522 | |
26fbace8 |
523 | This can be very useful for recursive classes like trees. Here is a |
5cfe3805 |
524 | quick example (soon to be expanded into a Moose::Cookbook recipe): |
38e3283b |
525 | |
1cd45431 |
526 | package Tree; |
38e3283b |
527 | use Moose; |
26fbace8 |
528 | |
38e3283b |
529 | has 'node' => (is => 'rw', isa => 'Any'); |
26fbace8 |
530 | |
38e3283b |
531 | has 'children' => ( |
532 | is => 'ro', |
533 | isa => 'ArrayRef', |
534 | default => sub { [] } |
535 | ); |
26fbace8 |
536 | |
38e3283b |
537 | has 'parent' => ( |
538 | is => 'rw', |
539 | isa => 'Tree', |
a4e516f6 |
540 | weak_ref => 1, |
38e3283b |
541 | handles => { |
542 | parent_node => 'node', |
26fbace8 |
543 | siblings => 'children', |
38e3283b |
544 | } |
545 | ); |
546 | |
1cd45431 |
547 | In this example, the Tree package gets C<parent_node> and C<siblings> methods, |
548 | which delegate to the C<node> and C<children> methods (respectively) of the Tree |
26fbace8 |
549 | instance stored in the C<parent> slot. |
38e3283b |
550 | |
551 | =item C<REGEXP> |
552 | |
26fbace8 |
553 | The regexp option works very similar to the ARRAY option, except that it builds |
554 | the list of methods for you. It starts by collecting all possible methods of the |
555 | class being delegated to, then filters that list using the regexp supplied here. |
38e3283b |
556 | |
26fbace8 |
557 | B<NOTE:> An I<isa> option is required when using the regexp option format. This |
558 | is so that we can determine (at compile time) the method list from the class. |
38e3283b |
559 | Without an I<isa> this is just not possible. |
560 | |
c84f324f |
561 | =item C<ROLE> |
562 | |
26fbace8 |
563 | With the role option, you specify the name of a role whose "interface" then |
564 | becomes the list of methods to handle. The "interface" can be defined as; the |
565 | methods of the role and any required methods of the role. It should be noted |
566 | that this does B<not> include any method modifiers or generated attribute |
c84f324f |
567 | methods (which is consistent with role composition). |
568 | |
38e3283b |
569 | =item C<CODE> |
570 | |
1cd45431 |
571 | This is the option to use when you really want to do something funky. You should |
572 | only use it if you really know what you are doing, as it involves manual |
573 | metaclass twiddling. |
38e3283b |
574 | |
1cd45431 |
575 | This takes a code reference, which should expect two arguments. The first is the |
576 | attribute meta-object this I<handles> is attached to. The second is the |
577 | metaclass of the class being delegated to. It expects you to return a hash (not |
26fbace8 |
578 | a HASH ref) of the methods you want mapped. |
38e3283b |
579 | |
580 | =back |
2c0cbef7 |
581 | |
004222dc |
582 | =item I<metaclass =E<gt> $metaclass_name> |
583 | |
584 | This tells the class to use a custom attribute metaclass for this particular |
585 | attribute. Custom attribute metaclasses are useful for extending the |
586 | capabilities of the I<has> keyword: they are the simplest way to extend the MOP, |
587 | but they are still a fairly advanced topic and too much to cover here, see |
5cfe3805 |
588 | L<Moose::Cookbook::Meta::Recipe1> for more information. |
004222dc |
589 | |
590 | The default behavior here is to just load C<$metaclass_name>; however, we also |
591 | have a way to alias to a shorter name. This will first look to see if |
592 | B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose |
593 | will then check to see if that has the method C<register_implementation>, which |
594 | should return the actual name of the custom attribute metaclass. If there is no |
595 | C<register_implementation> method, it will fall back to using |
596 | B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name. |
597 | |
598 | =item I<traits =E<gt> [ @role_names ]> |
599 | |
600 | This tells Moose to take the list of C<@role_names> and apply them to the |
601 | attribute meta-object. This is very similar to the I<metaclass> option, but |
54f2996d |
602 | allows you to use more than one extension at a time. |
004222dc |
603 | |
54f2996d |
604 | See L<TRAIT NAME RESOLUTION> for details on how a trait name is |
605 | resolved to a class name. |
606 | |
607 | Also see L<Moose::Cookbook::Meta::Recipe3> for a metaclass trait |
608 | example. |
004222dc |
609 | |
6ba6d68c |
610 | =back |
611 | |
cd7eeaf5 |
612 | =item B<has +$name =E<gt> %options> |
613 | |
26fbace8 |
614 | This is variation on the normal attibute creator C<has> which allows you to |
8d62bf6d |
615 | clone and extend an attribute from a superclass or from a role. Here is an |
616 | example of the superclass usage: |
cd7eeaf5 |
617 | |
618 | package Foo; |
619 | use Moose; |
26fbace8 |
620 | |
cd7eeaf5 |
621 | has 'message' => ( |
26fbace8 |
622 | is => 'rw', |
cd7eeaf5 |
623 | isa => 'Str', |
624 | default => 'Hello, I am a Foo' |
625 | ); |
26fbace8 |
626 | |
cd7eeaf5 |
627 | package My::Foo; |
628 | use Moose; |
26fbace8 |
629 | |
cd7eeaf5 |
630 | extends 'Foo'; |
26fbace8 |
631 | |
cd7eeaf5 |
632 | has '+message' => (default => 'Hello I am My::Foo'); |
633 | |
1cd45431 |
634 | What is happening here is that B<My::Foo> is cloning the C<message> attribute |
635 | from its parent class B<Foo>, retaining the C<is =E<gt> 'rw'> and C<isa =E<gt> |
636 | 'Str'> characteristics, but changing the value in C<default>. |
cd7eeaf5 |
637 | |
8d62bf6d |
638 | Here is another example, but within the context of a role: |
639 | |
640 | package Foo::Role; |
641 | use Moose::Role; |
986d175a |
642 | |
8d62bf6d |
643 | has 'message' => ( |
644 | is => 'rw', |
645 | isa => 'Str', |
646 | default => 'Hello, I am a Foo' |
647 | ); |
986d175a |
648 | |
8d62bf6d |
649 | package My::Foo; |
650 | use Moose; |
986d175a |
651 | |
8d62bf6d |
652 | with 'Foo::Role'; |
986d175a |
653 | |
8d62bf6d |
654 | has '+message' => (default => 'Hello I am My::Foo'); |
655 | |
656 | In this case, we are basically taking the attribute which the role supplied |
4032c9bb |
657 | and altering it within the bounds of this feature. |
8d62bf6d |
658 | |
4032c9bb |
659 | Aside from where the attributes come from (one from superclass, the other |
660 | from a role), this feature works exactly the same. This feature is restricted |
661 | somewhat, so as to try and force at least I<some> sanity into it. You are only |
662 | allowed to change the following attributes: |
cd7eeaf5 |
663 | |
664 | =over 4 |
665 | |
26fbace8 |
666 | =item I<default> |
cd7eeaf5 |
667 | |
668 | Change the default value of an attribute. |
669 | |
26fbace8 |
670 | =item I<coerce> |
cd7eeaf5 |
671 | |
672 | Change whether the attribute attempts to coerce a value passed to it. |
673 | |
26fbace8 |
674 | =item I<required> |
cd7eeaf5 |
675 | |
676 | Change if the attribute is required to have a value. |
677 | |
678 | =item I<documentation> |
679 | |
680 | Change the documentation string associated with the attribute. |
681 | |
83cc9094 |
682 | =item I<lazy> |
683 | |
684 | Change if the attribute lazily initializes the slot. |
685 | |
cd7eeaf5 |
686 | =item I<isa> |
687 | |
aed87761 |
688 | You I<are> allowed to change the type without restriction. |
689 | |
690 | It is recommended that you use this freedom with caution. We used to |
691 | only allow for extension only if the type was a subtype of the parent's |
692 | type, but we felt that was too restrictive and is better left as a |
693 | policy descision. |
cd7eeaf5 |
694 | |
83cc9094 |
695 | =item I<handles> |
696 | |
26fbace8 |
697 | You are allowed to B<add> a new C<handles> definition, but you are B<not> |
698 | allowed to I<change> one. |
83cc9094 |
699 | |
8d62bf6d |
700 | =item I<builder> |
701 | |
702 | You are allowed to B<add> a new C<builder> definition, but you are B<not> |
703 | allowed to I<change> one. |
704 | |
13284479 |
705 | =item I<metaclass> |
706 | |
707 | You are allowed to B<add> a new C<metaclass> definition, but you are |
708 | B<not> allowed to I<change> one. |
709 | |
710 | =item I<traits> |
711 | |
712 | You are allowed to B<add> additional traits to the C<traits> definition. |
713 | These traits will be composed into the attribute, but pre-existing traits |
714 | B<are not> overridden, or removed. |
715 | |
cd7eeaf5 |
716 | =back |
717 | |
076c81ed |
718 | =item B<before $name|@names =E<gt> sub { ... }> |
6ba6d68c |
719 | |
076c81ed |
720 | =item B<after $name|@names =E<gt> sub { ... }> |
6ba6d68c |
721 | |
076c81ed |
722 | =item B<around $name|@names =E<gt> sub { ... }> |
6ba6d68c |
723 | |
d8af92ae |
724 | This three items are syntactic sugar for the before, after, and around method |
725 | modifier features that L<Class::MOP> provides. More information on these may be |
726 | found in the L<Class::MOP::Class documentation|Class::MOP::Class/"Method |
727 | Modifiers"> for now. |
6ba6d68c |
728 | |
159da176 |
729 | =item B<super> |
730 | |
26fbace8 |
731 | The keyword C<super> is a no-op when called outside of an C<override> method. In |
732 | the context of an C<override> method, it will call the next most appropriate |
159da176 |
733 | superclass method with the same arguments as the original method. |
734 | |
735 | =item B<override ($name, &sub)> |
736 | |
26fbace8 |
737 | An C<override> method is a way of explicitly saying "I am overriding this |
738 | method from my superclass". You can call C<super> within this method, and |
739 | it will work as expected. The same thing I<can> be accomplished with a normal |
740 | method call and the C<SUPER::> pseudo-package; it is really your choice. |
159da176 |
741 | |
742 | =item B<inner> |
743 | |
26fbace8 |
744 | The keyword C<inner>, much like C<super>, is a no-op outside of the context of |
745 | an C<augment> method. You can think of C<inner> as being the inverse of |
68efb014 |
746 | C<super>; the details of how C<inner> and C<augment> work is best described in |
5cfe3805 |
747 | the L<Moose::Cookbook::Basics::Recipe6>. |
159da176 |
748 | |
749 | =item B<augment ($name, &sub)> |
750 | |
26fbace8 |
751 | An C<augment> method, is a way of explicitly saying "I am augmenting this |
752 | method from my superclass". Once again, the details of how C<inner> and |
5cfe3805 |
753 | C<augment> work is best described in the L<Moose::Cookbook::Basics::Recipe6>. |
159da176 |
754 | |
6ba6d68c |
755 | =item B<confess> |
756 | |
68efb014 |
757 | This is the C<Carp::confess> function, and exported here because I use it |
004222dc |
758 | all the time. |
6ba6d68c |
759 | |
760 | =item B<blessed> |
761 | |
1cd45431 |
762 | This is the C<Scalar::Util::blessed> function, it is exported here because I |
26fbace8 |
763 | use it all the time. It is highly recommended that this is used instead of |
6ba6d68c |
764 | C<ref> anywhere you need to test for an object's class name. |
765 | |
766 | =back |
767 | |
54f2996d |
768 | =head1 METACLASS TRAITS |
769 | |
770 | When you use Moose, you can also specify traits which will be applied |
771 | to your metaclass: |
772 | |
773 | use Moose -traits => 'My::Trait'; |
774 | |
775 | This is very similar to the attribute traits feature. When you do |
776 | this, your class's C<meta> object will have the specified traits |
777 | applied to it. See L<TRAIT NAME RESOLUTION> for more details. |
778 | |
779 | =head1 TRAIT NAME RESOLUTION |
780 | |
781 | By default, when given a trait name, Moose simply tries to load a |
782 | class of the same name. If such a class does not exist, it then looks |
783 | for for a class matching |
784 | B<Moose::Meta::$type::Custom::Trait::$trait_name>. The C<$type> |
785 | variable here will be one of B<Attribute> or B<Class>, depending on |
786 | what the trait is being applied to. |
787 | |
788 | If a class with this long name exists, Moose checks to see if it has |
789 | the method C<register_implementation>. This method is expected to |
790 | return the I<real> class name of the trait. If there is no |
791 | C<register_implementation> method, it will fall back to using |
792 | B<Moose::Meta::$type::Custom::Trait::$trait> as the trait name. |
793 | |
794 | If all this is confusing, take a look at |
795 | L<Moose::Cookbook::Meta::Recipe3>, which demonstrates how to create an |
796 | attribute trait. |
797 | |
1cd45431 |
798 | =head1 UNIMPORTING FUNCTIONS |
31f8ec72 |
799 | |
800 | =head2 B<unimport> |
801 | |
1cd45431 |
802 | Moose offers a way to remove the keywords it exports, through the C<unimport> |
31f8ec72 |
803 | method. You simply have to say C<no Moose> at the bottom of your code for this |
804 | to work. Here is an example: |
805 | |
806 | package Person; |
807 | use Moose; |
808 | |
809 | has 'first_name' => (is => 'rw', isa => 'Str'); |
810 | has 'last_name' => (is => 'rw', isa => 'Str'); |
26fbace8 |
811 | |
812 | sub full_name { |
31f8ec72 |
813 | my $self = shift; |
26fbace8 |
814 | $self->first_name . ' ' . $self->last_name |
31f8ec72 |
815 | } |
26fbace8 |
816 | |
817 | no Moose; # keywords are removed from the Person package |
31f8ec72 |
818 | |
9bcfbab1 |
819 | =head1 EXTENDING AND EMBEDDING MOOSE |
820 | |
5e86efbe |
821 | To learn more about extending Moose, we recommend checking out the |
822 | "Extending" recipes in the L<Moose::Cookbook>, starting with |
823 | L<Moose::Cookbook::Extending::Recipe1>, which provides an overview of |
824 | all the different ways you might extend Moose. |
554b7648 |
825 | |
826 | =head2 B<< Moose->init_meta(for_class => $class, base_class => $baseclass, metaclass => $metaclass) >> |
9bcfbab1 |
827 | |
554b7648 |
828 | The C<init_meta> method sets up the metaclass object for the class |
b143539e |
829 | specified by C<for_class>. This method injects a a C<meta> accessor |
830 | into the class so you can get at this object. It also sets the class's |
554b7648 |
831 | superclass to C<base_class>, with L<Moose::Object> as the default. |
9bcfbab1 |
832 | |
554b7648 |
833 | You can specify an alternate metaclass with the C<metaclass> parameter. |
26fbace8 |
834 | |
80837fe1 |
835 | For more detail on this topic, see L<Moose::Cookbook::Extending::Recipe2>. |
836 | |
554b7648 |
837 | This method used to be documented as a function which accepted |
838 | positional parameters. This calling style will still work for |
4a66a4b3 |
839 | backwards compatibility, but is deprecated. |
554b7648 |
840 | |
841 | =head2 B<import> |
842 | |
843 | Moose's C<import> method supports the L<Sub::Exporter> form of C<{into =E<gt> $pkg}> |
844 | and C<{into_level =E<gt> 1}>. |
845 | |
846 | B<NOTE>: Doing this is more or less deprecated. Use L<Moose::Exporter> |
847 | instead, which lets you stack multiple C<Moose.pm>-alike modules |
848 | sanely. It handles getting the exported functions into the right place |
849 | for you. |
850 | |
4c0b3599 |
851 | =head2 throw_error |
852 | |
853 | An alias for C<confess>, used by internally by Moose. |
854 | |
05d9eaf6 |
855 | =head1 CAVEATS |
856 | |
857 | =over 4 |
858 | |
859 | =item * |
860 | |
1cd45431 |
861 | It should be noted that C<super> and C<inner> B<cannot> be used in the same |
862 | method. However, they may be combined within the same class hierarchy; see |
863 | F<t/014_override_augment_inner_super.t> for an example. |
05d9eaf6 |
864 | |
26fbace8 |
865 | The reason for this is that C<super> is only valid within a method |
866 | with the C<override> modifier, and C<inner> will never be valid within an |
867 | C<override> method. In fact, C<augment> will skip over any C<override> methods |
68efb014 |
868 | when searching for its appropriate C<inner>. |
05d9eaf6 |
869 | |
1cd45431 |
870 | This might seem like a restriction, but I am of the opinion that keeping these |
871 | two features separate (yet interoperable) actually makes them easy to use, since |
872 | their behavior is then easier to predict. Time will tell whether I am right or |
c84f324f |
873 | not (UPDATE: so far so good). |
05d9eaf6 |
874 | |
9b9da6f1 |
875 | =back |
876 | |
5569c072 |
877 | =head1 ACKNOWLEDGEMENTS |
878 | |
879 | =over 4 |
880 | |
54c189df |
881 | =item I blame Sam Vilain for introducing me to the insanity that is meta-models. |
5569c072 |
882 | |
54c189df |
883 | =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6. |
5569c072 |
884 | |
26fbace8 |
885 | =item Without Yuval "nothingmuch" Kogman this module would not be possible, |
54c189df |
886 | and it certainly wouldn't have this name ;P |
5569c072 |
887 | |
26fbace8 |
888 | =item The basis of the TypeContraints module was Rob Kinyon's idea |
5569c072 |
889 | originally, I just ran with it. |
890 | |
638585e1 |
891 | =item Thanks to mst & chansen and the whole #moose posse for all the |
c84f324f |
892 | early ideas/feature-requests/encouragement/bug-finding. |
d46a48f3 |
893 | |
68efb014 |
894 | =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes. |
895 | |
5569c072 |
896 | =back |
897 | |
e90c03d0 |
898 | =head1 SEE ALSO |
899 | |
900 | =over 4 |
901 | |
c84f324f |
902 | =item L<http://www.iinteractive.com/moose> |
903 | |
904 | This is the official web home of Moose, it contains links to our public SVN repo |
26fbace8 |
905 | as well as links to a number of talks and articles on Moose and Moose related |
906 | technologies. |
c84f324f |
907 | |
196064ab |
908 | =item L<Moose::Cookbook> - How to cook a Moose |
909 | |
910 | =item The Moose is flying, a tutorial by Randal Schwartz |
911 | |
912 | Part 1 - L<http://www.stonehenge.com/merlyn/LinuxMag/col94.html> |
913 | |
914 | Part 2 - L<http://www.stonehenge.com/merlyn/LinuxMag/col95.html> |
915 | |
6ba6d68c |
916 | =item L<Class::MOP> documentation |
917 | |
918 | =item The #moose channel on irc.perl.org |
919 | |
e67a0fca |
920 | =item The Moose mailing list - moose@perl.org |
921 | |
9e0361e1 |
922 | =item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/moose> |
c84f324f |
923 | |
12aed9a0 |
924 | =item Several Moose extension modules in the C<MooseX::> namespace. |
925 | |
926 | See L<http://search.cpan.org/search?query=MooseX::> for extensions. |
28669f89 |
927 | |
c84f324f |
928 | =back |
929 | |
004222dc |
930 | =head2 Books |
931 | |
932 | =over 4 |
933 | |
934 | =item The Art of the MetaObject Protocol |
935 | |
936 | I mention this in the L<Class::MOP> docs too, this book was critical in |
937 | the development of both modules and is highly recommended. |
938 | |
939 | =back |
940 | |
26fbace8 |
941 | =head2 Papers |
c84f324f |
942 | |
943 | =over 4 |
e90c03d0 |
944 | |
159da176 |
945 | =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf> |
946 | |
26fbace8 |
947 | This paper (suggested by lbr on #moose) was what lead to the implementation |
948 | of the C<super>/C<override> and C<inner>/C<augment> features. If you really |
1cd45431 |
949 | want to understand them, I suggest you read this. |
159da176 |
950 | |
e90c03d0 |
951 | =back |
952 | |
fcd84ca9 |
953 | =head1 BUGS |
954 | |
26fbace8 |
955 | All complex software has bugs lurking in it, and this module is no |
fcd84ca9 |
956 | exception. If you find a bug please either email me, or add the bug |
957 | to cpan-RT. |
958 | |
47b19570 |
959 | =head1 FEATURE REQUESTS |
960 | |
961 | We are very strict about what features we add to the Moose core, especially |
962 | the user-visible features. Instead we have made sure that the underlying |
963 | meta-system of Moose is as extensible as possible so that you can add your |
964 | own features easily. That said, occasionally there is a feature needed in the |
965 | meta-system to support your planned extension, in which case you should |
966 | either email the mailing list or join us on irc at #moose to discuss. |
967 | |
fcd84ca9 |
968 | =head1 AUTHOR |
969 | |
970 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
971 | |
9af1d28b |
972 | B<with contributions from:> |
db1ab48d |
973 | |
9af1d28b |
974 | Aankhen |
975 | |
976 | Adam (Alias) Kennedy |
977 | |
978 | Anders (Debolaz) Nor Berle |
979 | |
5868294f |
980 | Nathan (kolibre) Gray |
981 | |
9af1d28b |
982 | Christian (chansen) Hansen |
983 | |
e7f8d0c2 |
984 | Hans Dieter (confound) Pearcey |
985 | |
9af1d28b |
986 | Eric (ewilhelm) Wilhelm |
987 | |
988 | Guillermo (groditi) Roditi |
989 | |
990 | Jess (castaway) Robinson |
991 | |
992 | Matt (mst) Trout |
993 | |
994 | Robert (phaylon) Sedlacek |
995 | |
996 | Robert (rlb3) Boone |
997 | |
998 | Scott (konobi) McWhirter |
999 | |
f44ae52f |
1000 | Shlomi (rindolf) Fish |
1001 | |
9af1d28b |
1002 | Yuval (nothingmuch) Kogman |
1003 | |
cbe25729 |
1004 | Chris (perigrin) Prather |
1005 | |
68b6146c |
1006 | Wallace (wreis) Reis |
1007 | |
e46f5cc2 |
1008 | Jonathan (jrockway) Rockway |
1009 | |
abfdc2b4 |
1010 | Dave (autarch) Rolsky |
1011 | |
3ccdc84a |
1012 | Piotr (dexter) Roszatycki |
1013 | |
26fbace8 |
1014 | Sam (mugwump) Vilain |
f1917f58 |
1015 | |
ac211120 |
1016 | Shawn (sartak) Moore |
1017 | |
9af1d28b |
1018 | ... and many other #moose folks |
98aae381 |
1019 | |
fcd84ca9 |
1020 | =head1 COPYRIGHT AND LICENSE |
1021 | |
778db3ac |
1022 | Copyright 2006-2008 by Infinity Interactive, Inc. |
fcd84ca9 |
1023 | |
1024 | L<http://www.iinteractive.com> |
1025 | |
1026 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
1027 | it under the same terms as Perl itself. |
fcd84ca9 |
1028 | |
ddd0ec20 |
1029 | =cut |