Commit | Line | Data |
fcd84ca9 |
1 | |
2 | package Moose; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
688fcdda |
7 | our $VERSION = '0.37'; |
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 | |
d7d8a8c7 |
16 | use Class::MOP 0.51; |
ef1d5f4b |
17 | |
c0e30cf5 |
18 | use Moose::Meta::Class; |
7415b2cb |
19 | use Moose::Meta::TypeConstraint; |
3fef8ce8 |
20 | use Moose::Meta::TypeConstraint::Class; |
7c13858b |
21 | use Moose::Meta::TypeCoercion; |
78cd1d3b |
22 | use Moose::Meta::Attribute; |
ddd0ec20 |
23 | use Moose::Meta::Instance; |
c0e30cf5 |
24 | |
d67145ed |
25 | use Moose::Meta::Role; |
26 | |
fcd84ca9 |
27 | use Moose::Object; |
7415b2cb |
28 | use Moose::Util::TypeConstraints; |
d7d8a8c7 |
29 | use Moose::Util (); |
a15dff8d |
30 | |
a3c7e2fe |
31 | { |
be33e4f3 |
32 | my $CALLER; |
9bcfbab1 |
33 | |
34 | sub init_meta { |
35 | my ( $class, $base_class, $metaclass ) = @_; |
688fcdda |
36 | $base_class = 'Moose::Object' unless defined $base_class; |
37 | $metaclass = 'Moose::Meta::Class' unless defined $metaclass; |
9bcfbab1 |
38 | |
39 | confess |
97e11ef5 |
40 | "The Metaclass $metaclass must be a subclass of Moose::Meta::Class." |
41 | unless $metaclass->isa('Moose::Meta::Class'); |
a3c7e2fe |
42 | |
a3c7e2fe |
43 | # make a subtype for each Moose class |
3fef8ce8 |
44 | class_type($class) |
45 | unless find_type_constraint($class); |
a3c7e2fe |
46 | |
47 | my $meta; |
9bcfbab1 |
48 | if ( $class->can('meta') ) { |
fcec2383 |
49 | # NOTE: |
9bcfbab1 |
50 | # this is the case where the metaclass pragma |
51 | # was used before the 'use Moose' statement to |
fcec2383 |
52 | # override a specific class |
a3c7e2fe |
53 | $meta = $class->meta(); |
9bcfbab1 |
54 | ( blessed($meta) && $meta->isa('Moose::Meta::Class') ) |
1edfdf1c |
55 | || confess "You already have a &meta function, but it does not return a Moose::Meta::Class"; |
a3c7e2fe |
56 | } |
57 | else { |
fcec2383 |
58 | # NOTE: |
9bcfbab1 |
59 | # this is broken currently, we actually need |
60 | # to allow the possiblity of an inherited |
61 | # meta, which will not be visible until the |
62 | # user 'extends' first. This needs to have |
63 | # more intelligence to it |
64 | $meta = $metaclass->initialize($class); |
65 | $meta->add_method( |
66 | 'meta' => sub { |
9bcfbab1 |
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(); |
688fcdda |
76 | |
77 | return $meta; |
a3c7e2fe |
78 | } |
79 | |
80 | my %exports = ( |
81 | extends => sub { |
be33e4f3 |
82 | my $class = $CALLER; |
68117c45 |
83 | return subname 'Moose::extends' => sub (@) { |
84 | confess "Must derive at least one class" unless @_; |
1eaed09d |
85 | Class::MOP::load_class($_) for @_; |
9bcfbab1 |
86 | |
87 | # this checks the metaclass to make sure |
88 | # it is correct, sometimes it can get out |
1341f10c |
89 | # of sync when the classes are being built |
90 | my $meta = $class->meta->_fix_metaclass_incompatability(@_); |
be33e4f3 |
91 | $meta->superclasses(@_); |
a3c7e2fe |
92 | }; |
93 | }, |
94 | with => sub { |
be33e4f3 |
95 | my $class = $CALLER; |
68117c45 |
96 | return subname 'Moose::with' => sub (@) { |
d7d8a8c7 |
97 | Moose::Util::apply_all_roles($class->meta, @_) |
a3c7e2fe |
98 | }; |
99 | }, |
100 | has => sub { |
be33e4f3 |
101 | my $class = $CALLER; |
2c0cbef7 |
102 | return subname 'Moose::has' => sub ($;%) { |
9bcfbab1 |
103 | my ( $name, %options ) = @_; |
104 | my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; |
d7d8a8c7 |
105 | $class->meta->add_attribute( $_, %options ) for @$attrs; |
a3c7e2fe |
106 | }; |
107 | }, |
108 | before => sub { |
be33e4f3 |
109 | my $class = $CALLER; |
2c0cbef7 |
110 | return subname 'Moose::before' => sub (@&) { |
a3c7e2fe |
111 | my $code = pop @_; |
be33e4f3 |
112 | my $meta = $class->meta; |
9bcfbab1 |
113 | $meta->add_before_method_modifier( $_, $code ) for @_; |
a3c7e2fe |
114 | }; |
115 | }, |
116 | after => sub { |
be33e4f3 |
117 | my $class = $CALLER; |
2c0cbef7 |
118 | return subname 'Moose::after' => sub (@&) { |
a3c7e2fe |
119 | my $code = pop @_; |
be33e4f3 |
120 | my $meta = $class->meta; |
9bcfbab1 |
121 | $meta->add_after_method_modifier( $_, $code ) for @_; |
a3c7e2fe |
122 | }; |
123 | }, |
124 | around => sub { |
9bcfbab1 |
125 | my $class = $CALLER; |
2c0cbef7 |
126 | return subname 'Moose::around' => sub (@&) { |
a3c7e2fe |
127 | my $code = pop @_; |
be33e4f3 |
128 | my $meta = $class->meta; |
9bcfbab1 |
129 | $meta->add_around_method_modifier( $_, $code ) for @_; |
a3c7e2fe |
130 | }; |
131 | }, |
132 | super => sub { |
52c7c330 |
133 | { |
9bcfbab1 |
134 | our %SUPER_SLOT; |
135 | no strict 'refs'; |
136 | $SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"}; |
52c7c330 |
137 | } |
9bcfbab1 |
138 | return subname 'Moose::super' => sub { }; |
a3c7e2fe |
139 | }, |
140 | override => sub { |
be33e4f3 |
141 | my $class = $CALLER; |
2c0cbef7 |
142 | return subname 'Moose::override' => sub ($&) { |
9bcfbab1 |
143 | my ( $name, $method ) = @_; |
144 | $class->meta->add_override_method_modifier( $name => $method ); |
a3c7e2fe |
145 | }; |
146 | }, |
147 | inner => sub { |
52c7c330 |
148 | { |
9bcfbab1 |
149 | our %INNER_SLOT; |
150 | no strict 'refs'; |
151 | $INNER_SLOT{$CALLER} = \*{"${CALLER}::inner"}; |
52c7c330 |
152 | } |
9bcfbab1 |
153 | return subname 'Moose::inner' => sub { }; |
a3c7e2fe |
154 | }, |
155 | augment => sub { |
be33e4f3 |
156 | my $class = $CALLER; |
2c0cbef7 |
157 | return subname 'Moose::augment' => sub (@&) { |
9bcfbab1 |
158 | my ( $name, $method ) = @_; |
159 | $class->meta->add_augment_method_modifier( $name => $method ); |
a3c7e2fe |
160 | }; |
161 | }, |
162 | confess => sub { |
163 | return \&Carp::confess; |
164 | }, |
165 | blessed => sub { |
166 | return \&Scalar::Util::blessed; |
66bcefc1 |
167 | }, |
a3c7e2fe |
168 | ); |
3d544ed5 |
169 | |
9bcfbab1 |
170 | my $exporter = Sub::Exporter::build_exporter( |
171 | { |
172 | exports => \%exports, |
173 | groups => { default => [':all'] } |
a3c7e2fe |
174 | } |
9bcfbab1 |
175 | ); |
176 | |
c92c1205 |
177 | # 1 extra level because it's called by import so there's a layer of indirection |
178 | sub _get_caller{ |
179 | my $offset = 1; |
26fbace8 |
180 | return |
c92c1205 |
181 | ref $_[1] && defined $_[1]->{into} |
182 | ? $_[1]->{into} |
183 | : ref $_[1] && defined $_[1]->{into_level} |
184 | ? caller($offset + $_[1]->{into_level}) |
185 | : caller($offset); |
186 | } |
5bee491d |
187 | |
188 | sub import { |
c92c1205 |
189 | $CALLER = _get_caller(@_); |
26fbace8 |
190 | |
c235cd98 |
191 | strict->import; |
9bcfbab1 |
192 | warnings->import; |
a3c7e2fe |
193 | |
194 | # we should never export to main |
195 | return if $CALLER eq 'main'; |
9bcfbab1 |
196 | |
197 | init_meta( $CALLER, 'Moose::Object' ); |
198 | |
a3c7e2fe |
199 | goto $exporter; |
fcb7afc2 |
200 | } |
9bcfbab1 |
201 | |
31f8ec72 |
202 | sub unimport { |
9bcfbab1 |
203 | no strict 'refs'; |
c92c1205 |
204 | my $class = _get_caller(@_); |
9bcfbab1 |
205 | |
31f8ec72 |
206 | # loop through the exports ... |
9bcfbab1 |
207 | foreach my $name ( keys %exports ) { |
208 | |
31f8ec72 |
209 | # if we find one ... |
9bcfbab1 |
210 | if ( defined &{ $class . '::' . $name } ) { |
211 | my $keyword = \&{ $class . '::' . $name }; |
212 | |
31f8ec72 |
213 | # make sure it is from Moose |
53dd42d8 |
214 | my ($pkg_name) = Class::MOP::get_code_info($keyword); |
31f8ec72 |
215 | next if $@; |
216 | next if $pkg_name ne 'Moose'; |
9bcfbab1 |
217 | |
31f8ec72 |
218 | # and if it is from Moose then undef the slot |
9bcfbab1 |
219 | delete ${ $class . '::' }{$name}; |
31f8ec72 |
220 | } |
221 | } |
222 | } |
9bcfbab1 |
223 | |
fcd84ca9 |
224 | } |
225 | |
8ecb1fa0 |
226 | ## make 'em all immutable |
227 | |
228 | $_->meta->make_immutable( |
229 | inline_constructor => 0, |
77a18c28 |
230 | inline_accessors => 1, # these are Class::MOP accessors, so they need inlining |
9bcfbab1 |
231 | ) |
232 | for ( |
8ecb1fa0 |
233 | 'Moose::Meta::Attribute', |
234 | 'Moose::Meta::Class', |
235 | 'Moose::Meta::Instance', |
236 | |
237 | 'Moose::Meta::TypeConstraint', |
238 | 'Moose::Meta::TypeConstraint::Union', |
0fbd4b0a |
239 | 'Moose::Meta::TypeConstraint::Parameterized', |
8ecb1fa0 |
240 | 'Moose::Meta::TypeCoercion', |
241 | |
242 | 'Moose::Meta::Method', |
243 | 'Moose::Meta::Method::Accessor', |
244 | 'Moose::Meta::Method::Constructor', |
9bcfbab1 |
245 | 'Moose::Meta::Method::Destructor', |
8ecb1fa0 |
246 | 'Moose::Meta::Method::Overriden', |
d67145ed |
247 | |
248 | 'Moose::Meta::Role', |
9bcfbab1 |
249 | 'Moose::Meta::Role::Method', |
250 | 'Moose::Meta::Role::Method::Required', |
251 | ); |
8ecb1fa0 |
252 | |
fcd84ca9 |
253 | 1; |
254 | |
255 | __END__ |
256 | |
257 | =pod |
258 | |
259 | =head1 NAME |
260 | |
8bdc7f13 |
261 | Moose - A postmodern object system for Perl 5 |
fcd84ca9 |
262 | |
263 | =head1 SYNOPSIS |
e522431d |
264 | |
265 | package Point; |
1cd45431 |
266 | use Moose; # automatically turns on strict and warnings |
26fbace8 |
267 | |
43d599e5 |
268 | has 'x' => (is => 'rw', isa => 'Int'); |
269 | has 'y' => (is => 'rw', isa => 'Int'); |
26fbace8 |
270 | |
e522431d |
271 | sub clear { |
272 | my $self = shift; |
273 | $self->x(0); |
26fbace8 |
274 | $self->y(0); |
e522431d |
275 | } |
26fbace8 |
276 | |
e522431d |
277 | package Point3D; |
278 | use Moose; |
26fbace8 |
279 | |
e522431d |
280 | extends 'Point'; |
26fbace8 |
281 | |
43d599e5 |
282 | has 'z' => (is => 'rw', isa => 'Int'); |
26fbace8 |
283 | |
e522431d |
284 | after 'clear' => sub { |
285 | my $self = shift; |
43d599e5 |
286 | $self->z(0); |
26fbace8 |
287 | }; |
2c0cbef7 |
288 | |
fcd84ca9 |
289 | =head1 DESCRIPTION |
290 | |
26fbace8 |
291 | Moose is an extension of the Perl 5 object system. |
e522431d |
292 | |
293 | =head2 Another object system!?!? |
fcd84ca9 |
294 | |
26fbace8 |
295 | Yes, I know there has been an explosion recently of new ways to |
68efb014 |
296 | build object's in Perl 5, most of them based on inside-out objects |
26fbace8 |
297 | and other such things. Moose is different because it is not a new |
298 | object system for Perl 5, but instead an extension of the existing |
e522431d |
299 | object system. |
3c7278fb |
300 | |
26fbace8 |
301 | Moose is built on top of L<Class::MOP>, which is a metaclass system |
302 | for Perl 5. This means that Moose not only makes building normal |
303 | Perl 5 objects better, but it also provides the power of metaclass |
505c6fac |
304 | programming. |
e522431d |
305 | |
734d1752 |
306 | =head2 Is this for real? Or is this just an experiment? |
e522431d |
307 | |
2c0cbef7 |
308 | Moose is I<based> on the prototypes and experiments I did for the Perl 6 |
26fbace8 |
309 | meta-model. However, Moose is B<NOT> an experiment/prototype; it is for B<real>. |
734d1752 |
310 | |
26fbace8 |
311 | =head2 Is this ready for use in production? |
d44714be |
312 | |
26fbace8 |
313 | Yes, I believe that it is. |
734d1752 |
314 | |
26fbace8 |
315 | Moose has been used successfully in production environemnts by several people |
316 | and companies (including the one I work for). There are Moose applications |
8bdc7f13 |
317 | which have been in production with little or no issue now for well over a year. |
26fbace8 |
318 | I consider it highly stable and we are commited to keeping it stable. |
e522431d |
319 | |
26fbace8 |
320 | Of course, in the end, you need to make this call yourself. If you have |
321 | any questions or concerns, please feel free to email me, or even the list |
d44714be |
322 | or just stop by #moose and ask away. |
323 | |
43d599e5 |
324 | =head2 Is Moose just Perl 6 in Perl 5? |
e522431d |
325 | |
68efb014 |
326 | No. While Moose is very much inspired by Perl 6, it is not itself Perl 6. |
1cd45431 |
327 | Instead, it is an OO system for Perl 5. I built Moose because I was tired of |
68efb014 |
328 | writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So |
329 | instead of switching to Ruby, I wrote Moose :) |
3c7278fb |
330 | |
8bdc7f13 |
331 | =head2 Wait, I<post> modern, I thought it was just I<modern>? |
332 | |
333 | So I was reading Larry Wall's talk from the 1999 Linux World entitled |
334 | "Perl, the first postmodern computer language" in which he talks about how |
335 | he picked the features for Perl because he thought they were cool and he |
336 | threw out the ones that he thought sucked. This got me thinking about how |
337 | we have done the same thing in Moose. For Moose, we have "borrowed" features |
338 | from Perl 6, CLOS (LISP), Smalltalk, Java, BETA, OCaml, Ruby and more, and |
339 | the bits we didn't like (cause they sucked) we tossed aside. So for this |
340 | reason (and a few others) I have re-dubbed Moose a I<postmodern> object system. |
341 | |
342 | Nuff Said. |
343 | |
28669f89 |
344 | =head2 Moose Extensions |
345 | |
346 | The L<MooseX::> namespace is the official place to find Moose extensions. |
0b26305c |
347 | There are a number of these modules out on CPAN right now the best way to |
348 | find them is to search for MooseX:: on search.cpan.org. |
28669f89 |
349 | |
6ba6d68c |
350 | =head1 BUILDING CLASSES WITH MOOSE |
351 | |
68efb014 |
352 | Moose makes every attempt to provide as much convenience as possible during |
353 | class construction/definition, but still stay out of your way if you want it |
354 | to. Here are a few items to note when building classes with Moose. |
6ba6d68c |
355 | |
26fbace8 |
356 | Unless specified with C<extends>, any class which uses Moose will |
6ba6d68c |
357 | inherit from L<Moose::Object>. |
358 | |
1cd45431 |
359 | Moose will also manage all attributes (including inherited ones) that are |
360 | defined with C<has>. And (assuming you call C<new>, which is inherited from |
361 | L<Moose::Object>) this includes properly initializing all instance slots, |
362 | setting defaults where appropriate, and performing any type constraint checking |
363 | or coercion. |
6ba6d68c |
364 | |
365 | =head1 EXPORTED FUNCTIONS |
366 | |
26fbace8 |
367 | Moose will export a number of functions into the class's namespace which |
368 | may then be used to set up the class. These functions all work directly |
6ba6d68c |
369 | on the current class. |
370 | |
371 | =over 4 |
372 | |
373 | =item B<meta> |
374 | |
375 | This is a method which provides access to the current class's metaclass. |
376 | |
377 | =item B<extends (@superclasses)> |
378 | |
379 | This function will set the superclass(es) for the current class. |
380 | |
26fbace8 |
381 | This approach is recommended instead of C<use base>, because C<use base> |
382 | actually C<push>es onto the class's C<@ISA>, whereas C<extends> will |
383 | replace it. This is important to ensure that classes which do not have |
68efb014 |
384 | superclasses still properly inherit from L<Moose::Object>. |
6ba6d68c |
385 | |
43d599e5 |
386 | =item B<with (@roles)> |
e9ec68d6 |
387 | |
26fbace8 |
388 | This will apply a given set of C<@roles> to the local class. Role support |
68efb014 |
389 | is currently under heavy development; see L<Moose::Role> for more details. |
e9ec68d6 |
390 | |
cd7eeaf5 |
391 | =item B<has $name =E<gt> %options> |
6ba6d68c |
392 | |
26fbace8 |
393 | This will install an attribute of a given C<$name> into the current class. |
394 | The C<%options> are the same as those provided by |
395 | L<Class::MOP::Attribute>, in addition to the list below which are provided |
43d599e5 |
396 | by Moose (L<Moose::Meta::Attribute> to be more specific): |
6ba6d68c |
397 | |
398 | =over 4 |
399 | |
076c81ed |
400 | =item I<is =E<gt> 'rw'|'ro'> |
6ba6d68c |
401 | |
26fbace8 |
402 | The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read |
403 | only). These will create either a read/write accessor or a read-only |
6ba6d68c |
404 | accessor respectively, using the same name as the C<$name> of the attribute. |
405 | |
1cd45431 |
406 | If you need more control over how your accessors are named, you can use the |
407 | I<reader>, I<writer> and I<accessor> options inherited from |
408 | L<Class::MOP::Attribute>. |
6ba6d68c |
409 | |
076c81ed |
410 | =item I<isa =E<gt> $type_name> |
6ba6d68c |
411 | |
26fbace8 |
412 | The I<isa> option uses Moose's type constraint facilities to set up runtime |
413 | type checking for this attribute. Moose will perform the checks during class |
414 | construction, and within any accessors. The C<$type_name> argument must be a |
415 | string. The string may be either a class name or a type defined using |
9cca2e9e |
416 | Moose's type definition features. (Refer to L<Moose::Util::TypeConstraints> |
c2a69ef1 |
417 | for information on how to define a new type, and how to retrieve type meta-data). |
6ba6d68c |
418 | |
daea75c9 |
419 | =item I<coerce =E<gt> (1|0)> |
420 | |
26fbace8 |
421 | This will attempt to use coercion with the supplied type constraint to change |
422 | the value passed into any accessors or constructors. You B<must> have supplied |
daea75c9 |
423 | a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5> |
1cd45431 |
424 | for an example. |
daea75c9 |
425 | |
426 | =item I<does =E<gt> $role_name> |
427 | |
26fbace8 |
428 | This will accept the name of a role which the value stored in this attribute |
daea75c9 |
429 | is expected to have consumed. |
430 | |
431 | =item I<required =E<gt> (1|0)> |
432 | |
26fbace8 |
433 | This marks the attribute as being required. This means a I<defined> value must be |
434 | supplied during class construction, and the attribute may never be set to |
435 | C<undef> with an accessor. |
daea75c9 |
436 | |
437 | =item I<weak_ref =E<gt> (1|0)> |
438 | |
68efb014 |
439 | This will tell the class to store the value of this attribute as a weakened |
440 | reference. If an attribute is a weakened reference, it B<cannot> also be |
441 | coerced. |
daea75c9 |
442 | |
443 | =item I<lazy =E<gt> (1|0)> |
444 | |
26fbace8 |
445 | This will tell the class to not create this slot until absolutely necessary. |
daea75c9 |
446 | If an attribute is marked as lazy it B<must> have a default supplied. |
447 | |
9e93dd19 |
448 | =item I<auto_deref =E<gt> (1|0)> |
449 | |
26fbace8 |
450 | This tells the accessor whether to automatically dereference the value returned. |
1cd45431 |
451 | This is only legal if your C<isa> option is either C<ArrayRef> or C<HashRef>. |
9e93dd19 |
452 | |
c1935ade |
453 | =item I<metaclass =E<gt> $metaclass_name> |
454 | |
1cd45431 |
455 | This tells the class to use a custom attribute metaclass for this particular |
456 | attribute. Custom attribute metaclasses are useful for extending the |
457 | capabilities of the I<has> keyword: they are the simplest way to extend the MOP, |
458 | but they are still a fairly advanced topic and too much to cover here. I will |
459 | try and write a recipe on them soon. |
460 | |
461 | The default behavior here is to just load C<$metaclass_name>; however, we also |
462 | have a way to alias to a shorter name. This will first look to see if |
463 | B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose |
32dd4a95 |
464 | will then check to see if that has the method C<register_implementation>, which |
1cd45431 |
465 | should return the actual name of the custom attribute metaclass. If there is no |
32dd4a95 |
466 | C<register_implementation> method, it will fall back to using |
c1935ade |
467 | B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name. |
468 | |
daea75c9 |
469 | =item I<trigger =E<gt> $code> |
470 | |
1cd45431 |
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 |
daea75c9 |
473 | updated value and the attribute meta-object (this is for more advanced fiddling |
1cd45431 |
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:> This feature is no longer experimental, but it may still have subtle |
484 | bugs lurking in the deeper corners. If you think you have found a bug, you |
26fbace8 |
485 | probably have, so please report it to me right away. |
38e3283b |
486 | |
1cd45431 |
487 | B<NOTE:> The class being delegated to does not need to be a Moose based class, |
488 | which is why this feature is especially useful when wrapping non-Moose classes. |
38e3283b |
489 | |
1cd45431 |
490 | All I<handles> option formats share the following traits: |
38e3283b |
491 | |
1cd45431 |
492 | You cannot override a locally defined method with a delegated method; an |
493 | exception will be thrown if you try. That is to say, if you define C<foo> in |
494 | your class, you cannot override it with a delegated C<foo>. This is almost never |
495 | something you would want to do, and if it is, you should do it by hand and not |
496 | use Moose. |
38e3283b |
497 | |
1cd45431 |
498 | You cannot override any of the methods found in Moose::Object, or the C<BUILD> |
499 | and C<DEMOLISH> methods. These will not throw an exception, but will silently |
500 | move on to the next method in the list. My reasoning for this is that you would |
501 | almost never want to do this, since it usually breaks your class. As with |
502 | overriding locally defined methods, if you do want to do this, you should do it |
503 | manually, not with Moose. |
38e3283b |
504 | |
f3c4e20e |
505 | You do not I<need> to have a reader (or accessor) for the attribute in order |
506 | to delegate to it. Moose will create a means of accessing the value for you, |
507 | however this will be several times B<less> efficient then if you had given |
508 | the attribute a reader (or accessor) to use. |
509 | |
38e3283b |
510 | Below is the documentation for each option format: |
511 | |
512 | =over 4 |
513 | |
514 | =item C<ARRAY> |
515 | |
26fbace8 |
516 | This is the most common usage for I<handles>. You basically pass a list of |
517 | method names to be delegated, and Moose will install a delegation method |
1cd45431 |
518 | for each one. |
38e3283b |
519 | |
520 | =item C<HASH> |
521 | |
26fbace8 |
522 | This is the second most common usage for I<handles>. Instead of a list of |
523 | method names, you pass a HASH ref where each key is the method name you |
524 | want installed locally, and its value is the name of the original method |
525 | in the class being delegated to. |
fd595040 |
526 | |
26fbace8 |
527 | This can be very useful for recursive classes like trees. Here is a |
fd595040 |
528 | quick example (soon to be expanded into a Moose::Cookbook::Recipe): |
38e3283b |
529 | |
1cd45431 |
530 | package Tree; |
38e3283b |
531 | use Moose; |
26fbace8 |
532 | |
38e3283b |
533 | has 'node' => (is => 'rw', isa => 'Any'); |
26fbace8 |
534 | |
38e3283b |
535 | has 'children' => ( |
536 | is => 'ro', |
537 | isa => 'ArrayRef', |
538 | default => sub { [] } |
539 | ); |
26fbace8 |
540 | |
38e3283b |
541 | has 'parent' => ( |
542 | is => 'rw', |
543 | isa => 'Tree', |
a4e516f6 |
544 | weak_ref => 1, |
38e3283b |
545 | handles => { |
546 | parent_node => 'node', |
26fbace8 |
547 | siblings => 'children', |
38e3283b |
548 | } |
549 | ); |
550 | |
1cd45431 |
551 | In this example, the Tree package gets C<parent_node> and C<siblings> methods, |
552 | which delegate to the C<node> and C<children> methods (respectively) of the Tree |
26fbace8 |
553 | instance stored in the C<parent> slot. |
38e3283b |
554 | |
555 | =item C<REGEXP> |
556 | |
26fbace8 |
557 | The regexp option works very similar to the ARRAY option, except that it builds |
558 | the list of methods for you. It starts by collecting all possible methods of the |
559 | class being delegated to, then filters that list using the regexp supplied here. |
38e3283b |
560 | |
26fbace8 |
561 | B<NOTE:> An I<isa> option is required when using the regexp option format. This |
562 | is so that we can determine (at compile time) the method list from the class. |
38e3283b |
563 | Without an I<isa> this is just not possible. |
564 | |
c84f324f |
565 | =item C<ROLE> |
566 | |
26fbace8 |
567 | With the role option, you specify the name of a role whose "interface" then |
568 | becomes the list of methods to handle. The "interface" can be defined as; the |
569 | methods of the role and any required methods of the role. It should be noted |
570 | that this does B<not> include any method modifiers or generated attribute |
c84f324f |
571 | methods (which is consistent with role composition). |
572 | |
38e3283b |
573 | =item C<CODE> |
574 | |
1cd45431 |
575 | This is the option to use when you really want to do something funky. You should |
576 | only use it if you really know what you are doing, as it involves manual |
577 | metaclass twiddling. |
38e3283b |
578 | |
1cd45431 |
579 | This takes a code reference, which should expect two arguments. The first is the |
580 | attribute meta-object this I<handles> is attached to. The second is the |
581 | metaclass of the class being delegated to. It expects you to return a hash (not |
26fbace8 |
582 | a HASH ref) of the methods you want mapped. |
38e3283b |
583 | |
584 | =back |
2c0cbef7 |
585 | |
6ba6d68c |
586 | =back |
587 | |
cd7eeaf5 |
588 | =item B<has +$name =E<gt> %options> |
589 | |
26fbace8 |
590 | This is variation on the normal attibute creator C<has> which allows you to |
cd7eeaf5 |
591 | clone and extend an attribute from a superclass. Here is a quick example: |
592 | |
593 | package Foo; |
594 | use Moose; |
26fbace8 |
595 | |
cd7eeaf5 |
596 | has 'message' => ( |
26fbace8 |
597 | is => 'rw', |
cd7eeaf5 |
598 | isa => 'Str', |
599 | default => 'Hello, I am a Foo' |
600 | ); |
26fbace8 |
601 | |
cd7eeaf5 |
602 | package My::Foo; |
603 | use Moose; |
26fbace8 |
604 | |
cd7eeaf5 |
605 | extends 'Foo'; |
26fbace8 |
606 | |
cd7eeaf5 |
607 | has '+message' => (default => 'Hello I am My::Foo'); |
608 | |
1cd45431 |
609 | What is happening here is that B<My::Foo> is cloning the C<message> attribute |
610 | from its parent class B<Foo>, retaining the C<is =E<gt> 'rw'> and C<isa =E<gt> |
611 | 'Str'> characteristics, but changing the value in C<default>. |
cd7eeaf5 |
612 | |
83cc9094 |
613 | This feature is restricted somewhat, so as to try and force at least I<some> |
cd7eeaf5 |
614 | sanity into it. You are only allowed to change the following attributes: |
615 | |
616 | =over 4 |
617 | |
26fbace8 |
618 | =item I<default> |
cd7eeaf5 |
619 | |
620 | Change the default value of an attribute. |
621 | |
26fbace8 |
622 | =item I<coerce> |
cd7eeaf5 |
623 | |
624 | Change whether the attribute attempts to coerce a value passed to it. |
625 | |
26fbace8 |
626 | =item I<required> |
cd7eeaf5 |
627 | |
628 | Change if the attribute is required to have a value. |
629 | |
630 | =item I<documentation> |
631 | |
632 | Change the documentation string associated with the attribute. |
633 | |
83cc9094 |
634 | =item I<lazy> |
635 | |
636 | Change if the attribute lazily initializes the slot. |
637 | |
cd7eeaf5 |
638 | =item I<isa> |
639 | |
1cd45431 |
640 | You I<are> allowed to change the type, B<if and only if> the new type is a |
641 | subtype of the old type. |
cd7eeaf5 |
642 | |
83cc9094 |
643 | =item I<handles> |
644 | |
26fbace8 |
645 | You are allowed to B<add> a new C<handles> definition, but you are B<not> |
646 | allowed to I<change> one. |
83cc9094 |
647 | |
cd7eeaf5 |
648 | =back |
649 | |
076c81ed |
650 | =item B<before $name|@names =E<gt> sub { ... }> |
6ba6d68c |
651 | |
076c81ed |
652 | =item B<after $name|@names =E<gt> sub { ... }> |
6ba6d68c |
653 | |
076c81ed |
654 | =item B<around $name|@names =E<gt> sub { ... }> |
6ba6d68c |
655 | |
d8af92ae |
656 | This three items are syntactic sugar for the before, after, and around method |
657 | modifier features that L<Class::MOP> provides. More information on these may be |
658 | found in the L<Class::MOP::Class documentation|Class::MOP::Class/"Method |
659 | Modifiers"> for now. |
6ba6d68c |
660 | |
159da176 |
661 | =item B<super> |
662 | |
26fbace8 |
663 | The keyword C<super> is a no-op when called outside of an C<override> method. In |
664 | the context of an C<override> method, it will call the next most appropriate |
159da176 |
665 | superclass method with the same arguments as the original method. |
666 | |
667 | =item B<override ($name, &sub)> |
668 | |
26fbace8 |
669 | An C<override> method is a way of explicitly saying "I am overriding this |
670 | method from my superclass". You can call C<super> within this method, and |
671 | it will work as expected. The same thing I<can> be accomplished with a normal |
672 | method call and the C<SUPER::> pseudo-package; it is really your choice. |
159da176 |
673 | |
674 | =item B<inner> |
675 | |
26fbace8 |
676 | The keyword C<inner>, much like C<super>, is a no-op outside of the context of |
677 | an C<augment> method. You can think of C<inner> as being the inverse of |
68efb014 |
678 | C<super>; the details of how C<inner> and C<augment> work is best described in |
159da176 |
679 | the L<Moose::Cookbook>. |
680 | |
681 | =item B<augment ($name, &sub)> |
682 | |
26fbace8 |
683 | An C<augment> method, is a way of explicitly saying "I am augmenting this |
684 | method from my superclass". Once again, the details of how C<inner> and |
159da176 |
685 | C<augment> work is best described in the L<Moose::Cookbook>. |
686 | |
6ba6d68c |
687 | =item B<confess> |
688 | |
68efb014 |
689 | This is the C<Carp::confess> function, and exported here because I use it |
26fbace8 |
690 | all the time. This feature may change in the future, so you have been warned. |
6ba6d68c |
691 | |
692 | =item B<blessed> |
693 | |
1cd45431 |
694 | This is the C<Scalar::Util::blessed> function, it is exported here because I |
26fbace8 |
695 | use it all the time. It is highly recommended that this is used instead of |
6ba6d68c |
696 | C<ref> anywhere you need to test for an object's class name. |
697 | |
698 | =back |
699 | |
1cd45431 |
700 | =head1 UNIMPORTING FUNCTIONS |
31f8ec72 |
701 | |
702 | =head2 B<unimport> |
703 | |
1cd45431 |
704 | Moose offers a way to remove the keywords it exports, through the C<unimport> |
31f8ec72 |
705 | method. You simply have to say C<no Moose> at the bottom of your code for this |
706 | to work. Here is an example: |
707 | |
708 | package Person; |
709 | use Moose; |
710 | |
711 | has 'first_name' => (is => 'rw', isa => 'Str'); |
712 | has 'last_name' => (is => 'rw', isa => 'Str'); |
26fbace8 |
713 | |
714 | sub full_name { |
31f8ec72 |
715 | my $self = shift; |
26fbace8 |
716 | $self->first_name . ' ' . $self->last_name |
31f8ec72 |
717 | } |
26fbace8 |
718 | |
719 | no Moose; # keywords are removed from the Person package |
31f8ec72 |
720 | |
9bcfbab1 |
721 | =head1 EXTENDING AND EMBEDDING MOOSE |
722 | |
26fbace8 |
723 | Moose also offers some options for extending or embedding it into your own |
9bcfbab1 |
724 | framework. The basic premise is to have something that sets up your class' |
26fbace8 |
725 | metaclass and export the moose declarators (C<has>, C<with>, C<extends>,...). |
9bcfbab1 |
726 | Here is an example: |
727 | |
728 | package MyFramework; |
729 | use Moose; |
26fbace8 |
730 | |
9bcfbab1 |
731 | sub import { |
732 | my $CALLER = caller(); |
733 | |
734 | strict->import; |
735 | warnings->import; |
736 | |
737 | # we should never export to main |
738 | return if $CALLER eq 'main'; |
739 | Moose::init_meta( $CALLER, 'MyFramework::Base' ); |
740 | Moose->import({into => $CALLER}); |
741 | |
742 | # Do my custom framework stuff |
26fbace8 |
743 | |
9bcfbab1 |
744 | return 1; |
745 | } |
26fbace8 |
746 | |
9bcfbab1 |
747 | =head2 B<import> |
748 | |
77a18c28 |
749 | Moose's C<import> method supports the L<Sub::Exporter> form of C<{into =E<gt> $pkg}> |
9bcfbab1 |
750 | and C<{into_level =E<gt> 1}> |
751 | |
752 | =head2 B<init_meta ($class, $baseclass, $metaclass)> |
753 | |
26fbace8 |
754 | Moose does some boot strapping: it creates a metaclass object for your class, |
755 | and then injects a C<meta> accessor into your class to retrieve it. Then it |
756 | sets your baseclass to Moose::Object or the value you pass in unless you already |
757 | have one. This is all done via C<init_meta> which takes the name of your class |
2bbba362 |
758 | and optionally a baseclass and a metaclass as arguments. |
26fbace8 |
759 | |
05d9eaf6 |
760 | =head1 CAVEATS |
761 | |
762 | =over 4 |
763 | |
764 | =item * |
765 | |
1cd45431 |
766 | It should be noted that C<super> and C<inner> B<cannot> be used in the same |
767 | method. However, they may be combined within the same class hierarchy; see |
768 | F<t/014_override_augment_inner_super.t> for an example. |
05d9eaf6 |
769 | |
26fbace8 |
770 | The reason for this is that C<super> is only valid within a method |
771 | with the C<override> modifier, and C<inner> will never be valid within an |
772 | C<override> method. In fact, C<augment> will skip over any C<override> methods |
68efb014 |
773 | when searching for its appropriate C<inner>. |
05d9eaf6 |
774 | |
1cd45431 |
775 | This might seem like a restriction, but I am of the opinion that keeping these |
776 | two features separate (yet interoperable) actually makes them easy to use, since |
777 | their behavior is then easier to predict. Time will tell whether I am right or |
c84f324f |
778 | not (UPDATE: so far so good). |
05d9eaf6 |
779 | |
780 | =back |
781 | |
5569c072 |
782 | =head1 ACKNOWLEDGEMENTS |
783 | |
784 | =over 4 |
785 | |
54c189df |
786 | =item I blame Sam Vilain for introducing me to the insanity that is meta-models. |
5569c072 |
787 | |
54c189df |
788 | =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6. |
5569c072 |
789 | |
26fbace8 |
790 | =item Without Yuval "nothingmuch" Kogman this module would not be possible, |
54c189df |
791 | and it certainly wouldn't have this name ;P |
5569c072 |
792 | |
26fbace8 |
793 | =item The basis of the TypeContraints module was Rob Kinyon's idea |
5569c072 |
794 | originally, I just ran with it. |
795 | |
26fbace8 |
796 | =item Thanks to mst & chansen and the whole #moose poose for all the |
c84f324f |
797 | early ideas/feature-requests/encouragement/bug-finding. |
d46a48f3 |
798 | |
68efb014 |
799 | =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes. |
800 | |
5569c072 |
801 | =back |
802 | |
e90c03d0 |
803 | =head1 SEE ALSO |
804 | |
805 | =over 4 |
806 | |
c84f324f |
807 | =item L<http://www.iinteractive.com/moose> |
808 | |
809 | This is the official web home of Moose, it contains links to our public SVN repo |
26fbace8 |
810 | as well as links to a number of talks and articles on Moose and Moose related |
811 | technologies. |
c84f324f |
812 | |
6ba6d68c |
813 | =item L<Class::MOP> documentation |
814 | |
815 | =item The #moose channel on irc.perl.org |
816 | |
e67a0fca |
817 | =item The Moose mailing list - moose@perl.org |
818 | |
c84f324f |
819 | =item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/5788> |
820 | |
28669f89 |
821 | =item Several Moose extension modules in the L<MooseX::> namespace. |
822 | |
c84f324f |
823 | =back |
824 | |
26fbace8 |
825 | =head2 Papers |
c84f324f |
826 | |
827 | =over 4 |
e90c03d0 |
828 | |
159da176 |
829 | =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf> |
830 | |
26fbace8 |
831 | This paper (suggested by lbr on #moose) was what lead to the implementation |
832 | of the C<super>/C<override> and C<inner>/C<augment> features. If you really |
1cd45431 |
833 | want to understand them, I suggest you read this. |
159da176 |
834 | |
e90c03d0 |
835 | =back |
836 | |
fcd84ca9 |
837 | =head1 BUGS |
838 | |
26fbace8 |
839 | All complex software has bugs lurking in it, and this module is no |
fcd84ca9 |
840 | exception. If you find a bug please either email me, or add the bug |
841 | to cpan-RT. |
842 | |
fcd84ca9 |
843 | =head1 AUTHOR |
844 | |
845 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
846 | |
9af1d28b |
847 | B<with contributions from:> |
db1ab48d |
848 | |
9af1d28b |
849 | Aankhen |
850 | |
851 | Adam (Alias) Kennedy |
852 | |
853 | Anders (Debolaz) Nor Berle |
854 | |
5868294f |
855 | Nathan (kolibre) Gray |
856 | |
9af1d28b |
857 | Christian (chansen) Hansen |
858 | |
e7f8d0c2 |
859 | Hans Dieter (confound) Pearcey |
860 | |
9af1d28b |
861 | Eric (ewilhelm) Wilhelm |
862 | |
863 | Guillermo (groditi) Roditi |
864 | |
865 | Jess (castaway) Robinson |
866 | |
867 | Matt (mst) Trout |
868 | |
869 | Robert (phaylon) Sedlacek |
870 | |
871 | Robert (rlb3) Boone |
872 | |
873 | Scott (konobi) McWhirter |
874 | |
f44ae52f |
875 | Shlomi (rindolf) Fish |
876 | |
9af1d28b |
877 | Yuval (nothingmuch) Kogman |
878 | |
cbe25729 |
879 | Chris (perigrin) Prather |
880 | |
e46f5cc2 |
881 | Jonathan (jrockway) Rockway |
882 | |
3ccdc84a |
883 | Piotr (dexter) Roszatycki |
884 | |
26fbace8 |
885 | Sam (mugwump) Vilain |
f1917f58 |
886 | |
ac211120 |
887 | Shawn (sartak) Moore |
888 | |
9af1d28b |
889 | ... and many other #moose folks |
98aae381 |
890 | |
fcd84ca9 |
891 | =head1 COPYRIGHT AND LICENSE |
892 | |
778db3ac |
893 | Copyright 2006-2008 by Infinity Interactive, Inc. |
fcd84ca9 |
894 | |
895 | L<http://www.iinteractive.com> |
896 | |
897 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
898 | it under the same terms as Perl itself. |
fcd84ca9 |
899 | |
ddd0ec20 |
900 | =cut |