Commit | Line | Data |
fcd84ca9 |
1 | |
2 | package Moose; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
97e11ef5 |
7 | our $VERSION = '0.33'; |
d44714be |
8 | our $AUTHORITY = 'cpan:STEVAN'; |
fcd84ca9 |
9 | |
cc65ead0 |
10 | use Scalar::Util 'blessed', 'reftype'; |
3796382a |
11 | use Carp 'confess'; |
12 | use Sub::Name 'subname'; |
fcd84ca9 |
13 | |
2d562421 |
14 | use Sub::Exporter; |
7f18097c |
15 | |
89a173f8 |
16 | use Class::MOP 0.49; |
ef1d5f4b |
17 | |
c0e30cf5 |
18 | use Moose::Meta::Class; |
7415b2cb |
19 | use Moose::Meta::TypeConstraint; |
7c13858b |
20 | use Moose::Meta::TypeCoercion; |
78cd1d3b |
21 | use Moose::Meta::Attribute; |
ddd0ec20 |
22 | use Moose::Meta::Instance; |
c0e30cf5 |
23 | |
d67145ed |
24 | use Moose::Meta::Role; |
25 | |
fcd84ca9 |
26 | use Moose::Object; |
7415b2cb |
27 | use Moose::Util::TypeConstraints; |
a15dff8d |
28 | |
a3c7e2fe |
29 | { |
be33e4f3 |
30 | my $CALLER; |
9bcfbab1 |
31 | |
32 | sub init_meta { |
33 | my ( $class, $base_class, $metaclass ) = @_; |
72bbc189 |
34 | $base_class = $class unless defined $base_class; |
26fbace8 |
35 | $metaclass = 'Moose::Meta::Class' unless defined $metaclass; |
9bcfbab1 |
36 | |
37 | confess |
97e11ef5 |
38 | "The Metaclass $metaclass must be a subclass of Moose::Meta::Class." |
39 | unless $metaclass->isa('Moose::Meta::Class'); |
a3c7e2fe |
40 | |
a3c7e2fe |
41 | # make a subtype for each Moose class |
9bcfbab1 |
42 | subtype $class => as 'Object' => where { $_->isa($class) } => |
97e11ef5 |
43 | optimize_as { blessed( $_[0] ) && $_[0]->isa($class) } |
a3c7e2fe |
44 | unless find_type_constraint($class); |
45 | |
46 | my $meta; |
9bcfbab1 |
47 | if ( $class->can('meta') ) { |
fcec2383 |
48 | # NOTE: |
9bcfbab1 |
49 | # this is the case where the metaclass pragma |
50 | # was used before the 'use Moose' statement to |
fcec2383 |
51 | # override a specific class |
a3c7e2fe |
52 | $meta = $class->meta(); |
9bcfbab1 |
53 | ( blessed($meta) && $meta->isa('Moose::Meta::Class') ) |
1edfdf1c |
54 | || confess "You already have a &meta function, but it does not return a Moose::Meta::Class"; |
a3c7e2fe |
55 | } |
56 | else { |
fcec2383 |
57 | # NOTE: |
9bcfbab1 |
58 | # this is broken currently, we actually need |
59 | # to allow the possiblity of an inherited |
60 | # meta, which will not be visible until the |
61 | # user 'extends' first. This needs to have |
62 | # more intelligence to it |
63 | $meta = $metaclass->initialize($class); |
64 | $meta->add_method( |
65 | 'meta' => sub { |
66 | |
67 | # re-initialize so it inherits properly |
68 | $metaclass->initialize( blessed( $_[0] ) || $_[0] ); |
69 | } |
70 | ); |
a3c7e2fe |
71 | } |
72 | |
73 | # make sure they inherit from Moose::Object |
72bbc189 |
74 | $meta->superclasses($base_class) |
9bcfbab1 |
75 | unless $meta->superclasses(); |
a3c7e2fe |
76 | } |
77 | |
78 | my %exports = ( |
79 | extends => sub { |
be33e4f3 |
80 | my $class = $CALLER; |
68117c45 |
81 | return subname 'Moose::extends' => sub (@) { |
82 | confess "Must derive at least one class" unless @_; |
1eaed09d |
83 | Class::MOP::load_class($_) for @_; |
9bcfbab1 |
84 | |
85 | # this checks the metaclass to make sure |
86 | # it is correct, sometimes it can get out |
1341f10c |
87 | # of sync when the classes are being built |
88 | my $meta = $class->meta->_fix_metaclass_incompatability(@_); |
be33e4f3 |
89 | $meta->superclasses(@_); |
a3c7e2fe |
90 | }; |
91 | }, |
92 | with => sub { |
be33e4f3 |
93 | my $class = $CALLER; |
68117c45 |
94 | return subname 'Moose::with' => sub (@) { |
db1ab48d |
95 | my (@roles) = @_; |
68117c45 |
96 | confess "Must specify at least one role" unless @roles; |
1eaed09d |
97 | Class::MOP::load_class($_) for @roles; |
1341f10c |
98 | $class->meta->_apply_all_roles(@roles); |
a3c7e2fe |
99 | }; |
100 | }, |
101 | has => sub { |
be33e4f3 |
102 | my $class = $CALLER; |
2c0cbef7 |
103 | return subname 'Moose::has' => sub ($;%) { |
9bcfbab1 |
104 | my ( $name, %options ) = @_; |
105 | my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; |
106 | $class->meta->_process_attribute( $_, %options ) for @$attrs; |
a3c7e2fe |
107 | }; |
108 | }, |
109 | before => sub { |
be33e4f3 |
110 | my $class = $CALLER; |
2c0cbef7 |
111 | return subname 'Moose::before' => sub (@&) { |
a3c7e2fe |
112 | my $code = pop @_; |
be33e4f3 |
113 | my $meta = $class->meta; |
9bcfbab1 |
114 | $meta->add_before_method_modifier( $_, $code ) for @_; |
a3c7e2fe |
115 | }; |
116 | }, |
117 | after => sub { |
be33e4f3 |
118 | my $class = $CALLER; |
2c0cbef7 |
119 | return subname 'Moose::after' => sub (@&) { |
a3c7e2fe |
120 | my $code = pop @_; |
be33e4f3 |
121 | my $meta = $class->meta; |
9bcfbab1 |
122 | $meta->add_after_method_modifier( $_, $code ) for @_; |
a3c7e2fe |
123 | }; |
124 | }, |
125 | around => sub { |
9bcfbab1 |
126 | my $class = $CALLER; |
2c0cbef7 |
127 | return subname 'Moose::around' => sub (@&) { |
a3c7e2fe |
128 | my $code = pop @_; |
be33e4f3 |
129 | my $meta = $class->meta; |
9bcfbab1 |
130 | $meta->add_around_method_modifier( $_, $code ) for @_; |
a3c7e2fe |
131 | }; |
132 | }, |
133 | super => sub { |
52c7c330 |
134 | { |
9bcfbab1 |
135 | our %SUPER_SLOT; |
136 | no strict 'refs'; |
137 | $SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"}; |
52c7c330 |
138 | } |
9bcfbab1 |
139 | return subname 'Moose::super' => sub { }; |
a3c7e2fe |
140 | }, |
141 | override => sub { |
be33e4f3 |
142 | my $class = $CALLER; |
2c0cbef7 |
143 | return subname 'Moose::override' => sub ($&) { |
9bcfbab1 |
144 | my ( $name, $method ) = @_; |
145 | $class->meta->add_override_method_modifier( $name => $method ); |
a3c7e2fe |
146 | }; |
147 | }, |
148 | inner => sub { |
52c7c330 |
149 | { |
9bcfbab1 |
150 | our %INNER_SLOT; |
151 | no strict 'refs'; |
152 | $INNER_SLOT{$CALLER} = \*{"${CALLER}::inner"}; |
52c7c330 |
153 | } |
9bcfbab1 |
154 | return subname 'Moose::inner' => sub { }; |
a3c7e2fe |
155 | }, |
156 | augment => sub { |
be33e4f3 |
157 | my $class = $CALLER; |
2c0cbef7 |
158 | return subname 'Moose::augment' => sub (@&) { |
9bcfbab1 |
159 | my ( $name, $method ) = @_; |
160 | $class->meta->add_augment_method_modifier( $name => $method ); |
a3c7e2fe |
161 | }; |
162 | }, |
163 | confess => sub { |
164 | return \&Carp::confess; |
165 | }, |
166 | blessed => sub { |
167 | return \&Scalar::Util::blessed; |
66bcefc1 |
168 | }, |
a3c7e2fe |
169 | ); |
3d544ed5 |
170 | |
9bcfbab1 |
171 | my $exporter = Sub::Exporter::build_exporter( |
172 | { |
173 | exports => \%exports, |
174 | groups => { default => [':all'] } |
a3c7e2fe |
175 | } |
9bcfbab1 |
176 | ); |
177 | |
c92c1205 |
178 | # 1 extra level because it's called by import so there's a layer of indirection |
179 | sub _get_caller{ |
180 | my $offset = 1; |
26fbace8 |
181 | return |
c92c1205 |
182 | ref $_[1] && defined $_[1]->{into} |
183 | ? $_[1]->{into} |
184 | : ref $_[1] && defined $_[1]->{into_level} |
185 | ? caller($offset + $_[1]->{into_level}) |
186 | : caller($offset); |
187 | } |
5bee491d |
188 | |
189 | sub import { |
c92c1205 |
190 | $CALLER = _get_caller(@_); |
26fbace8 |
191 | |
c235cd98 |
192 | strict->import; |
9bcfbab1 |
193 | warnings->import; |
a3c7e2fe |
194 | |
195 | # we should never export to main |
196 | return if $CALLER eq 'main'; |
9bcfbab1 |
197 | |
198 | init_meta( $CALLER, 'Moose::Object' ); |
199 | |
a3c7e2fe |
200 | goto $exporter; |
fcb7afc2 |
201 | } |
9bcfbab1 |
202 | |
31f8ec72 |
203 | sub unimport { |
9bcfbab1 |
204 | no strict 'refs'; |
c92c1205 |
205 | my $class = _get_caller(@_); |
9bcfbab1 |
206 | |
31f8ec72 |
207 | # loop through the exports ... |
9bcfbab1 |
208 | foreach my $name ( keys %exports ) { |
209 | |
31f8ec72 |
210 | # if we find one ... |
9bcfbab1 |
211 | if ( defined &{ $class . '::' . $name } ) { |
212 | my $keyword = \&{ $class . '::' . $name }; |
213 | |
31f8ec72 |
214 | # make sure it is from Moose |
53dd42d8 |
215 | my ($pkg_name) = Class::MOP::get_code_info($keyword); |
31f8ec72 |
216 | next if $@; |
217 | next if $pkg_name ne 'Moose'; |
9bcfbab1 |
218 | |
31f8ec72 |
219 | # and if it is from Moose then undef the slot |
9bcfbab1 |
220 | delete ${ $class . '::' }{$name}; |
31f8ec72 |
221 | } |
222 | } |
223 | } |
9bcfbab1 |
224 | |
fcd84ca9 |
225 | } |
226 | |
8ecb1fa0 |
227 | ## make 'em all immutable |
228 | |
229 | $_->meta->make_immutable( |
230 | inline_constructor => 0, |
77a18c28 |
231 | inline_accessors => 1, # these are Class::MOP accessors, so they need inlining |
9bcfbab1 |
232 | ) |
233 | for ( |
8ecb1fa0 |
234 | 'Moose::Meta::Attribute', |
235 | 'Moose::Meta::Class', |
236 | 'Moose::Meta::Instance', |
237 | |
238 | 'Moose::Meta::TypeConstraint', |
239 | 'Moose::Meta::TypeConstraint::Union', |
0fbd4b0a |
240 | 'Moose::Meta::TypeConstraint::Parameterized', |
8ecb1fa0 |
241 | 'Moose::Meta::TypeCoercion', |
242 | |
243 | 'Moose::Meta::Method', |
244 | 'Moose::Meta::Method::Accessor', |
245 | 'Moose::Meta::Method::Constructor', |
9bcfbab1 |
246 | 'Moose::Meta::Method::Destructor', |
8ecb1fa0 |
247 | 'Moose::Meta::Method::Overriden', |
d67145ed |
248 | |
249 | 'Moose::Meta::Role', |
9bcfbab1 |
250 | 'Moose::Meta::Role::Method', |
251 | 'Moose::Meta::Role::Method::Required', |
252 | ); |
8ecb1fa0 |
253 | |
fcd84ca9 |
254 | 1; |
255 | |
256 | __END__ |
257 | |
258 | =pod |
259 | |
260 | =head1 NAME |
261 | |
31f8ec72 |
262 | Moose - A complete modern object system for Perl 5 |
fcd84ca9 |
263 | |
264 | =head1 SYNOPSIS |
e522431d |
265 | |
266 | package Point; |
1cd45431 |
267 | use Moose; # automatically turns on strict and warnings |
26fbace8 |
268 | |
43d599e5 |
269 | has 'x' => (is => 'rw', isa => 'Int'); |
270 | has 'y' => (is => 'rw', isa => 'Int'); |
26fbace8 |
271 | |
e522431d |
272 | sub clear { |
273 | my $self = shift; |
274 | $self->x(0); |
26fbace8 |
275 | $self->y(0); |
e522431d |
276 | } |
26fbace8 |
277 | |
e522431d |
278 | package Point3D; |
279 | use Moose; |
26fbace8 |
280 | |
e522431d |
281 | extends 'Point'; |
26fbace8 |
282 | |
43d599e5 |
283 | has 'z' => (is => 'rw', isa => 'Int'); |
26fbace8 |
284 | |
e522431d |
285 | after 'clear' => sub { |
286 | my $self = shift; |
43d599e5 |
287 | $self->z(0); |
26fbace8 |
288 | }; |
2c0cbef7 |
289 | |
fcd84ca9 |
290 | =head1 DESCRIPTION |
291 | |
26fbace8 |
292 | Moose is an extension of the Perl 5 object system. |
e522431d |
293 | |
294 | =head2 Another object system!?!? |
fcd84ca9 |
295 | |
26fbace8 |
296 | Yes, I know there has been an explosion recently of new ways to |
68efb014 |
297 | build object's in Perl 5, most of them based on inside-out objects |
26fbace8 |
298 | and other such things. Moose is different because it is not a new |
299 | object system for Perl 5, but instead an extension of the existing |
e522431d |
300 | object system. |
3c7278fb |
301 | |
26fbace8 |
302 | Moose is built on top of L<Class::MOP>, which is a metaclass system |
303 | for Perl 5. This means that Moose not only makes building normal |
304 | Perl 5 objects better, but it also provides the power of metaclass |
505c6fac |
305 | programming. |
e522431d |
306 | |
734d1752 |
307 | =head2 Is this for real? Or is this just an experiment? |
e522431d |
308 | |
2c0cbef7 |
309 | Moose is I<based> on the prototypes and experiments I did for the Perl 6 |
26fbace8 |
310 | meta-model. However, Moose is B<NOT> an experiment/prototype; it is for B<real>. |
734d1752 |
311 | |
26fbace8 |
312 | =head2 Is this ready for use in production? |
d44714be |
313 | |
26fbace8 |
314 | Yes, I believe that it is. |
734d1752 |
315 | |
26fbace8 |
316 | Moose has been used successfully in production environemnts by several people |
317 | and companies (including the one I work for). There are Moose applications |
318 | which have been in production with little or no issue now for over a year. |
319 | I consider it highly stable and we are commited to keeping it stable. |
e522431d |
320 | |
26fbace8 |
321 | Of course, in the end, you need to make this call yourself. If you have |
322 | any questions or concerns, please feel free to email me, or even the list |
d44714be |
323 | or just stop by #moose and ask away. |
324 | |
43d599e5 |
325 | =head2 Is Moose just Perl 6 in Perl 5? |
e522431d |
326 | |
68efb014 |
327 | No. While Moose is very much inspired by Perl 6, it is not itself Perl 6. |
1cd45431 |
328 | Instead, it is an OO system for Perl 5. I built Moose because I was tired of |
68efb014 |
329 | writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So |
330 | instead of switching to Ruby, I wrote Moose :) |
3c7278fb |
331 | |
28669f89 |
332 | =head2 Moose Extensions |
333 | |
334 | The L<MooseX::> namespace is the official place to find Moose extensions. |
0b26305c |
335 | There are a number of these modules out on CPAN right now the best way to |
336 | find them is to search for MooseX:: on search.cpan.org. |
28669f89 |
337 | |
6ba6d68c |
338 | =head1 BUILDING CLASSES WITH MOOSE |
339 | |
68efb014 |
340 | Moose makes every attempt to provide as much convenience as possible during |
341 | class construction/definition, but still stay out of your way if you want it |
342 | to. Here are a few items to note when building classes with Moose. |
6ba6d68c |
343 | |
26fbace8 |
344 | Unless specified with C<extends>, any class which uses Moose will |
6ba6d68c |
345 | inherit from L<Moose::Object>. |
346 | |
1cd45431 |
347 | Moose will also manage all attributes (including inherited ones) that are |
348 | defined with C<has>. And (assuming you call C<new>, which is inherited from |
349 | L<Moose::Object>) this includes properly initializing all instance slots, |
350 | setting defaults where appropriate, and performing any type constraint checking |
351 | or coercion. |
6ba6d68c |
352 | |
353 | =head1 EXPORTED FUNCTIONS |
354 | |
26fbace8 |
355 | Moose will export a number of functions into the class's namespace which |
356 | may then be used to set up the class. These functions all work directly |
6ba6d68c |
357 | on the current class. |
358 | |
359 | =over 4 |
360 | |
361 | =item B<meta> |
362 | |
363 | This is a method which provides access to the current class's metaclass. |
364 | |
365 | =item B<extends (@superclasses)> |
366 | |
367 | This function will set the superclass(es) for the current class. |
368 | |
26fbace8 |
369 | This approach is recommended instead of C<use base>, because C<use base> |
370 | actually C<push>es onto the class's C<@ISA>, whereas C<extends> will |
371 | replace it. This is important to ensure that classes which do not have |
68efb014 |
372 | superclasses still properly inherit from L<Moose::Object>. |
6ba6d68c |
373 | |
43d599e5 |
374 | =item B<with (@roles)> |
e9ec68d6 |
375 | |
26fbace8 |
376 | This will apply a given set of C<@roles> to the local class. Role support |
68efb014 |
377 | is currently under heavy development; see L<Moose::Role> for more details. |
e9ec68d6 |
378 | |
cd7eeaf5 |
379 | =item B<has $name =E<gt> %options> |
6ba6d68c |
380 | |
26fbace8 |
381 | This will install an attribute of a given C<$name> into the current class. |
382 | The C<%options> are the same as those provided by |
383 | L<Class::MOP::Attribute>, in addition to the list below which are provided |
43d599e5 |
384 | by Moose (L<Moose::Meta::Attribute> to be more specific): |
6ba6d68c |
385 | |
386 | =over 4 |
387 | |
076c81ed |
388 | =item I<is =E<gt> 'rw'|'ro'> |
6ba6d68c |
389 | |
26fbace8 |
390 | The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read |
391 | only). These will create either a read/write accessor or a read-only |
6ba6d68c |
392 | accessor respectively, using the same name as the C<$name> of the attribute. |
393 | |
1cd45431 |
394 | If you need more control over how your accessors are named, you can use the |
395 | I<reader>, I<writer> and I<accessor> options inherited from |
396 | L<Class::MOP::Attribute>. |
6ba6d68c |
397 | |
076c81ed |
398 | =item I<isa =E<gt> $type_name> |
6ba6d68c |
399 | |
26fbace8 |
400 | The I<isa> option uses Moose's type constraint facilities to set up runtime |
401 | type checking for this attribute. Moose will perform the checks during class |
402 | construction, and within any accessors. The C<$type_name> argument must be a |
403 | string. The string may be either a class name or a type defined using |
9cca2e9e |
404 | Moose's type definition features. (Refer to L<Moose::Util::TypeConstraints> |
c2a69ef1 |
405 | for information on how to define a new type, and how to retrieve type meta-data). |
6ba6d68c |
406 | |
daea75c9 |
407 | =item I<coerce =E<gt> (1|0)> |
408 | |
26fbace8 |
409 | This will attempt to use coercion with the supplied type constraint to change |
410 | the value passed into any accessors or constructors. You B<must> have supplied |
daea75c9 |
411 | a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5> |
1cd45431 |
412 | for an example. |
daea75c9 |
413 | |
414 | =item I<does =E<gt> $role_name> |
415 | |
26fbace8 |
416 | This will accept the name of a role which the value stored in this attribute |
daea75c9 |
417 | is expected to have consumed. |
418 | |
419 | =item I<required =E<gt> (1|0)> |
420 | |
26fbace8 |
421 | This marks the attribute as being required. This means a I<defined> value must be |
422 | supplied during class construction, and the attribute may never be set to |
423 | C<undef> with an accessor. |
daea75c9 |
424 | |
425 | =item I<weak_ref =E<gt> (1|0)> |
426 | |
68efb014 |
427 | This will tell the class to store the value of this attribute as a weakened |
428 | reference. If an attribute is a weakened reference, it B<cannot> also be |
429 | coerced. |
daea75c9 |
430 | |
431 | =item I<lazy =E<gt> (1|0)> |
432 | |
26fbace8 |
433 | This will tell the class to not create this slot until absolutely necessary. |
daea75c9 |
434 | If an attribute is marked as lazy it B<must> have a default supplied. |
435 | |
9e93dd19 |
436 | =item I<auto_deref =E<gt> (1|0)> |
437 | |
26fbace8 |
438 | This tells the accessor whether to automatically dereference the value returned. |
1cd45431 |
439 | This is only legal if your C<isa> option is either C<ArrayRef> or C<HashRef>. |
9e93dd19 |
440 | |
c1935ade |
441 | =item I<metaclass =E<gt> $metaclass_name> |
442 | |
1cd45431 |
443 | This tells the class to use a custom attribute metaclass for this particular |
444 | attribute. Custom attribute metaclasses are useful for extending the |
445 | capabilities of the I<has> keyword: they are the simplest way to extend the MOP, |
446 | but they are still a fairly advanced topic and too much to cover here. I will |
447 | try and write a recipe on them soon. |
448 | |
449 | The default behavior here is to just load C<$metaclass_name>; however, we also |
450 | have a way to alias to a shorter name. This will first look to see if |
451 | B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose |
452 | will then check to see if that has the method C<register_implemenetation>, which |
453 | should return the actual name of the custom attribute metaclass. If there is no |
454 | C<register_implemenetation> method, it will fall back to using |
c1935ade |
455 | B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name. |
456 | |
daea75c9 |
457 | =item I<trigger =E<gt> $code> |
458 | |
1cd45431 |
459 | The I<trigger> option is a CODE reference which will be called after the value of |
460 | the attribute is set. The CODE ref will be passed the instance itself, the |
daea75c9 |
461 | updated value and the attribute meta-object (this is for more advanced fiddling |
1cd45431 |
462 | and can typically be ignored). You B<cannot> have a trigger on a read-only |
463 | attribute. |
daea75c9 |
464 | |
c84f324f |
465 | =item I<handles =E<gt> ARRAY | HASH | REGEXP | ROLE | CODE> |
2c0cbef7 |
466 | |
26fbace8 |
467 | The I<handles> option provides Moose classes with automated delegation features. |
468 | This is a pretty complex and powerful option. It accepts many different option |
469 | formats, each with its own benefits and drawbacks. |
38e3283b |
470 | |
1cd45431 |
471 | B<NOTE:> This feature is no longer experimental, but it may still have subtle |
472 | bugs lurking in the deeper corners. If you think you have found a bug, you |
26fbace8 |
473 | probably have, so please report it to me right away. |
38e3283b |
474 | |
1cd45431 |
475 | B<NOTE:> The class being delegated to does not need to be a Moose based class, |
476 | which is why this feature is especially useful when wrapping non-Moose classes. |
38e3283b |
477 | |
1cd45431 |
478 | All I<handles> option formats share the following traits: |
38e3283b |
479 | |
1cd45431 |
480 | You cannot override a locally defined method with a delegated method; an |
481 | exception will be thrown if you try. That is to say, if you define C<foo> in |
482 | your class, you cannot override it with a delegated C<foo>. This is almost never |
483 | something you would want to do, and if it is, you should do it by hand and not |
484 | use Moose. |
38e3283b |
485 | |
1cd45431 |
486 | You cannot override any of the methods found in Moose::Object, or the C<BUILD> |
487 | and C<DEMOLISH> methods. These will not throw an exception, but will silently |
488 | move on to the next method in the list. My reasoning for this is that you would |
489 | almost never want to do this, since it usually breaks your class. As with |
490 | overriding locally defined methods, if you do want to do this, you should do it |
491 | manually, not with Moose. |
38e3283b |
492 | |
f3c4e20e |
493 | You do not I<need> to have a reader (or accessor) for the attribute in order |
494 | to delegate to it. Moose will create a means of accessing the value for you, |
495 | however this will be several times B<less> efficient then if you had given |
496 | the attribute a reader (or accessor) to use. |
497 | |
38e3283b |
498 | Below is the documentation for each option format: |
499 | |
500 | =over 4 |
501 | |
502 | =item C<ARRAY> |
503 | |
26fbace8 |
504 | This is the most common usage for I<handles>. You basically pass a list of |
505 | method names to be delegated, and Moose will install a delegation method |
1cd45431 |
506 | for each one. |
38e3283b |
507 | |
508 | =item C<HASH> |
509 | |
26fbace8 |
510 | This is the second most common usage for I<handles>. Instead of a list of |
511 | method names, you pass a HASH ref where each key is the method name you |
512 | want installed locally, and its value is the name of the original method |
513 | in the class being delegated to. |
fd595040 |
514 | |
26fbace8 |
515 | This can be very useful for recursive classes like trees. Here is a |
fd595040 |
516 | quick example (soon to be expanded into a Moose::Cookbook::Recipe): |
38e3283b |
517 | |
1cd45431 |
518 | package Tree; |
38e3283b |
519 | use Moose; |
26fbace8 |
520 | |
38e3283b |
521 | has 'node' => (is => 'rw', isa => 'Any'); |
26fbace8 |
522 | |
38e3283b |
523 | has 'children' => ( |
524 | is => 'ro', |
525 | isa => 'ArrayRef', |
526 | default => sub { [] } |
527 | ); |
26fbace8 |
528 | |
38e3283b |
529 | has 'parent' => ( |
530 | is => 'rw', |
531 | isa => 'Tree', |
532 | is_weak_ref => 1, |
533 | handles => { |
534 | parent_node => 'node', |
26fbace8 |
535 | siblings => 'children', |
38e3283b |
536 | } |
537 | ); |
538 | |
1cd45431 |
539 | In this example, the Tree package gets C<parent_node> and C<siblings> methods, |
540 | which delegate to the C<node> and C<children> methods (respectively) of the Tree |
26fbace8 |
541 | instance stored in the C<parent> slot. |
38e3283b |
542 | |
543 | =item C<REGEXP> |
544 | |
26fbace8 |
545 | The regexp option works very similar to the ARRAY option, except that it builds |
546 | the list of methods for you. It starts by collecting all possible methods of the |
547 | class being delegated to, then filters that list using the regexp supplied here. |
38e3283b |
548 | |
26fbace8 |
549 | B<NOTE:> An I<isa> option is required when using the regexp option format. This |
550 | is so that we can determine (at compile time) the method list from the class. |
38e3283b |
551 | Without an I<isa> this is just not possible. |
552 | |
c84f324f |
553 | =item C<ROLE> |
554 | |
26fbace8 |
555 | With the role option, you specify the name of a role whose "interface" then |
556 | becomes the list of methods to handle. The "interface" can be defined as; the |
557 | methods of the role and any required methods of the role. It should be noted |
558 | that this does B<not> include any method modifiers or generated attribute |
c84f324f |
559 | methods (which is consistent with role composition). |
560 | |
38e3283b |
561 | =item C<CODE> |
562 | |
1cd45431 |
563 | This is the option to use when you really want to do something funky. You should |
564 | only use it if you really know what you are doing, as it involves manual |
565 | metaclass twiddling. |
38e3283b |
566 | |
1cd45431 |
567 | This takes a code reference, which should expect two arguments. The first is the |
568 | attribute meta-object this I<handles> is attached to. The second is the |
569 | metaclass of the class being delegated to. It expects you to return a hash (not |
26fbace8 |
570 | a HASH ref) of the methods you want mapped. |
38e3283b |
571 | |
572 | =back |
2c0cbef7 |
573 | |
6ba6d68c |
574 | =back |
575 | |
cd7eeaf5 |
576 | =item B<has +$name =E<gt> %options> |
577 | |
26fbace8 |
578 | This is variation on the normal attibute creator C<has> which allows you to |
cd7eeaf5 |
579 | clone and extend an attribute from a superclass. Here is a quick example: |
580 | |
581 | package Foo; |
582 | use Moose; |
26fbace8 |
583 | |
cd7eeaf5 |
584 | has 'message' => ( |
26fbace8 |
585 | is => 'rw', |
cd7eeaf5 |
586 | isa => 'Str', |
587 | default => 'Hello, I am a Foo' |
588 | ); |
26fbace8 |
589 | |
cd7eeaf5 |
590 | package My::Foo; |
591 | use Moose; |
26fbace8 |
592 | |
cd7eeaf5 |
593 | extends 'Foo'; |
26fbace8 |
594 | |
cd7eeaf5 |
595 | has '+message' => (default => 'Hello I am My::Foo'); |
596 | |
1cd45431 |
597 | What is happening here is that B<My::Foo> is cloning the C<message> attribute |
598 | from its parent class B<Foo>, retaining the C<is =E<gt> 'rw'> and C<isa =E<gt> |
599 | 'Str'> characteristics, but changing the value in C<default>. |
cd7eeaf5 |
600 | |
83cc9094 |
601 | This feature is restricted somewhat, so as to try and force at least I<some> |
cd7eeaf5 |
602 | sanity into it. You are only allowed to change the following attributes: |
603 | |
604 | =over 4 |
605 | |
26fbace8 |
606 | =item I<default> |
cd7eeaf5 |
607 | |
608 | Change the default value of an attribute. |
609 | |
26fbace8 |
610 | =item I<coerce> |
cd7eeaf5 |
611 | |
612 | Change whether the attribute attempts to coerce a value passed to it. |
613 | |
26fbace8 |
614 | =item I<required> |
cd7eeaf5 |
615 | |
616 | Change if the attribute is required to have a value. |
617 | |
618 | =item I<documentation> |
619 | |
620 | Change the documentation string associated with the attribute. |
621 | |
83cc9094 |
622 | =item I<lazy> |
623 | |
624 | Change if the attribute lazily initializes the slot. |
625 | |
cd7eeaf5 |
626 | =item I<isa> |
627 | |
1cd45431 |
628 | You I<are> allowed to change the type, B<if and only if> the new type is a |
629 | subtype of the old type. |
cd7eeaf5 |
630 | |
83cc9094 |
631 | =item I<handles> |
632 | |
26fbace8 |
633 | You are allowed to B<add> a new C<handles> definition, but you are B<not> |
634 | allowed to I<change> one. |
83cc9094 |
635 | |
cd7eeaf5 |
636 | =back |
637 | |
076c81ed |
638 | =item B<before $name|@names =E<gt> sub { ... }> |
6ba6d68c |
639 | |
076c81ed |
640 | =item B<after $name|@names =E<gt> sub { ... }> |
6ba6d68c |
641 | |
076c81ed |
642 | =item B<around $name|@names =E<gt> sub { ... }> |
6ba6d68c |
643 | |
d8af92ae |
644 | This three items are syntactic sugar for the before, after, and around method |
645 | modifier features that L<Class::MOP> provides. More information on these may be |
646 | found in the L<Class::MOP::Class documentation|Class::MOP::Class/"Method |
647 | Modifiers"> for now. |
6ba6d68c |
648 | |
159da176 |
649 | =item B<super> |
650 | |
26fbace8 |
651 | The keyword C<super> is a no-op when called outside of an C<override> method. In |
652 | the context of an C<override> method, it will call the next most appropriate |
159da176 |
653 | superclass method with the same arguments as the original method. |
654 | |
655 | =item B<override ($name, &sub)> |
656 | |
26fbace8 |
657 | An C<override> method is a way of explicitly saying "I am overriding this |
658 | method from my superclass". You can call C<super> within this method, and |
659 | it will work as expected. The same thing I<can> be accomplished with a normal |
660 | method call and the C<SUPER::> pseudo-package; it is really your choice. |
159da176 |
661 | |
662 | =item B<inner> |
663 | |
26fbace8 |
664 | The keyword C<inner>, much like C<super>, is a no-op outside of the context of |
665 | an C<augment> method. You can think of C<inner> as being the inverse of |
68efb014 |
666 | C<super>; the details of how C<inner> and C<augment> work is best described in |
159da176 |
667 | the L<Moose::Cookbook>. |
668 | |
669 | =item B<augment ($name, &sub)> |
670 | |
26fbace8 |
671 | An C<augment> method, is a way of explicitly saying "I am augmenting this |
672 | method from my superclass". Once again, the details of how C<inner> and |
159da176 |
673 | C<augment> work is best described in the L<Moose::Cookbook>. |
674 | |
6ba6d68c |
675 | =item B<confess> |
676 | |
68efb014 |
677 | This is the C<Carp::confess> function, and exported here because I use it |
26fbace8 |
678 | all the time. This feature may change in the future, so you have been warned. |
6ba6d68c |
679 | |
680 | =item B<blessed> |
681 | |
1cd45431 |
682 | This is the C<Scalar::Util::blessed> function, it is exported here because I |
26fbace8 |
683 | use it all the time. It is highly recommended that this is used instead of |
6ba6d68c |
684 | C<ref> anywhere you need to test for an object's class name. |
685 | |
686 | =back |
687 | |
1cd45431 |
688 | =head1 UNIMPORTING FUNCTIONS |
31f8ec72 |
689 | |
690 | =head2 B<unimport> |
691 | |
1cd45431 |
692 | Moose offers a way to remove the keywords it exports, through the C<unimport> |
31f8ec72 |
693 | method. You simply have to say C<no Moose> at the bottom of your code for this |
694 | to work. Here is an example: |
695 | |
696 | package Person; |
697 | use Moose; |
698 | |
699 | has 'first_name' => (is => 'rw', isa => 'Str'); |
700 | has 'last_name' => (is => 'rw', isa => 'Str'); |
26fbace8 |
701 | |
702 | sub full_name { |
31f8ec72 |
703 | my $self = shift; |
26fbace8 |
704 | $self->first_name . ' ' . $self->last_name |
31f8ec72 |
705 | } |
26fbace8 |
706 | |
707 | no Moose; # keywords are removed from the Person package |
31f8ec72 |
708 | |
9bcfbab1 |
709 | =head1 EXTENDING AND EMBEDDING MOOSE |
710 | |
26fbace8 |
711 | Moose also offers some options for extending or embedding it into your own |
9bcfbab1 |
712 | framework. The basic premise is to have something that sets up your class' |
26fbace8 |
713 | metaclass and export the moose declarators (C<has>, C<with>, C<extends>,...). |
9bcfbab1 |
714 | Here is an example: |
715 | |
716 | package MyFramework; |
717 | use Moose; |
26fbace8 |
718 | |
9bcfbab1 |
719 | sub import { |
720 | my $CALLER = caller(); |
721 | |
722 | strict->import; |
723 | warnings->import; |
724 | |
725 | # we should never export to main |
726 | return if $CALLER eq 'main'; |
727 | Moose::init_meta( $CALLER, 'MyFramework::Base' ); |
728 | Moose->import({into => $CALLER}); |
729 | |
730 | # Do my custom framework stuff |
26fbace8 |
731 | |
9bcfbab1 |
732 | return 1; |
733 | } |
26fbace8 |
734 | |
9bcfbab1 |
735 | =head2 B<import> |
736 | |
77a18c28 |
737 | Moose's C<import> method supports the L<Sub::Exporter> form of C<{into =E<gt> $pkg}> |
9bcfbab1 |
738 | and C<{into_level =E<gt> 1}> |
739 | |
740 | =head2 B<init_meta ($class, $baseclass, $metaclass)> |
741 | |
26fbace8 |
742 | Moose does some boot strapping: it creates a metaclass object for your class, |
743 | and then injects a C<meta> accessor into your class to retrieve it. Then it |
744 | sets your baseclass to Moose::Object or the value you pass in unless you already |
745 | have one. This is all done via C<init_meta> which takes the name of your class |
2bbba362 |
746 | and optionally a baseclass and a metaclass as arguments. |
26fbace8 |
747 | |
05d9eaf6 |
748 | =head1 CAVEATS |
749 | |
750 | =over 4 |
751 | |
752 | =item * |
753 | |
1cd45431 |
754 | It should be noted that C<super> and C<inner> B<cannot> be used in the same |
755 | method. However, they may be combined within the same class hierarchy; see |
756 | F<t/014_override_augment_inner_super.t> for an example. |
05d9eaf6 |
757 | |
26fbace8 |
758 | The reason for this is that C<super> is only valid within a method |
759 | with the C<override> modifier, and C<inner> will never be valid within an |
760 | C<override> method. In fact, C<augment> will skip over any C<override> methods |
68efb014 |
761 | when searching for its appropriate C<inner>. |
05d9eaf6 |
762 | |
1cd45431 |
763 | This might seem like a restriction, but I am of the opinion that keeping these |
764 | two features separate (yet interoperable) actually makes them easy to use, since |
765 | their behavior is then easier to predict. Time will tell whether I am right or |
c84f324f |
766 | not (UPDATE: so far so good). |
05d9eaf6 |
767 | |
768 | =back |
769 | |
5569c072 |
770 | =head1 ACKNOWLEDGEMENTS |
771 | |
772 | =over 4 |
773 | |
54c189df |
774 | =item I blame Sam Vilain for introducing me to the insanity that is meta-models. |
5569c072 |
775 | |
54c189df |
776 | =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6. |
5569c072 |
777 | |
26fbace8 |
778 | =item Without Yuval "nothingmuch" Kogman this module would not be possible, |
54c189df |
779 | and it certainly wouldn't have this name ;P |
5569c072 |
780 | |
26fbace8 |
781 | =item The basis of the TypeContraints module was Rob Kinyon's idea |
5569c072 |
782 | originally, I just ran with it. |
783 | |
26fbace8 |
784 | =item Thanks to mst & chansen and the whole #moose poose for all the |
c84f324f |
785 | early ideas/feature-requests/encouragement/bug-finding. |
d46a48f3 |
786 | |
68efb014 |
787 | =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes. |
788 | |
5569c072 |
789 | =back |
790 | |
e90c03d0 |
791 | =head1 SEE ALSO |
792 | |
793 | =over 4 |
794 | |
c84f324f |
795 | =item L<http://www.iinteractive.com/moose> |
796 | |
797 | This is the official web home of Moose, it contains links to our public SVN repo |
26fbace8 |
798 | as well as links to a number of talks and articles on Moose and Moose related |
799 | technologies. |
c84f324f |
800 | |
6ba6d68c |
801 | =item L<Class::MOP> documentation |
802 | |
803 | =item The #moose channel on irc.perl.org |
804 | |
e67a0fca |
805 | =item The Moose mailing list - moose@perl.org |
806 | |
c84f324f |
807 | =item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/5788> |
808 | |
28669f89 |
809 | =item Several Moose extension modules in the L<MooseX::> namespace. |
810 | |
c84f324f |
811 | =back |
812 | |
26fbace8 |
813 | =head2 Papers |
c84f324f |
814 | |
815 | =over 4 |
e90c03d0 |
816 | |
159da176 |
817 | =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf> |
818 | |
26fbace8 |
819 | This paper (suggested by lbr on #moose) was what lead to the implementation |
820 | of the C<super>/C<override> and C<inner>/C<augment> features. If you really |
1cd45431 |
821 | want to understand them, I suggest you read this. |
159da176 |
822 | |
e90c03d0 |
823 | =back |
824 | |
fcd84ca9 |
825 | =head1 BUGS |
826 | |
26fbace8 |
827 | All complex software has bugs lurking in it, and this module is no |
fcd84ca9 |
828 | exception. If you find a bug please either email me, or add the bug |
829 | to cpan-RT. |
830 | |
fcd84ca9 |
831 | =head1 AUTHOR |
832 | |
833 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
834 | |
9af1d28b |
835 | B<with contributions from:> |
db1ab48d |
836 | |
9af1d28b |
837 | Aankhen |
838 | |
839 | Adam (Alias) Kennedy |
840 | |
841 | Anders (Debolaz) Nor Berle |
842 | |
5868294f |
843 | Nathan (kolibre) Gray |
844 | |
9af1d28b |
845 | Christian (chansen) Hansen |
846 | |
e7f8d0c2 |
847 | Hans Dieter (confound) Pearcey |
848 | |
9af1d28b |
849 | Eric (ewilhelm) Wilhelm |
850 | |
851 | Guillermo (groditi) Roditi |
852 | |
853 | Jess (castaway) Robinson |
854 | |
855 | Matt (mst) Trout |
856 | |
857 | Robert (phaylon) Sedlacek |
858 | |
859 | Robert (rlb3) Boone |
860 | |
861 | Scott (konobi) McWhirter |
862 | |
f44ae52f |
863 | Shlomi (rindolf) Fish |
864 | |
9af1d28b |
865 | Yuval (nothingmuch) Kogman |
866 | |
cbe25729 |
867 | Chris (perigrin) Prather |
868 | |
e46f5cc2 |
869 | Jonathan (jrockway) Rockway |
870 | |
3ccdc84a |
871 | Piotr (dexter) Roszatycki |
872 | |
26fbace8 |
873 | Sam (mugwump) Vilain |
f1917f58 |
874 | |
ac211120 |
875 | Shawn (sartak) Moore |
876 | |
9af1d28b |
877 | ... and many other #moose folks |
98aae381 |
878 | |
fcd84ca9 |
879 | =head1 COPYRIGHT AND LICENSE |
880 | |
b77fdbed |
881 | Copyright 2006, 2007 by Infinity Interactive, Inc. |
fcd84ca9 |
882 | |
883 | L<http://www.iinteractive.com> |
884 | |
885 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
886 | it under the same terms as Perl itself. |
fcd84ca9 |
887 | |
ddd0ec20 |
888 | =cut |