Commit | Line | Data |
b1eebd55 |
1 | package Moo; |
6c74d087 |
2 | |
3 | use strictures 1; |
b1eebd55 |
4 | use Moo::_Utils; |
e0e12d16 |
5 | use B 'perlstring'; |
a41e15c3 |
6 | use Sub::Defer (); |
6c74d087 |
7 | |
8e0c8550 |
8 | our $VERSION = '1.000001'; # 1.0.1 |
6d71fae7 |
9 | $VERSION = eval $VERSION; |
10 | |
c2cb1fed |
11 | require Moo::sification; |
8c46a8f6 |
12 | |
14f32032 |
13 | our %MAKERS; |
14 | |
108f8ddc |
15 | sub _install_tracked { |
16 | my ($target, $name, $code) = @_; |
17 | $MAKERS{$target}{exports}{$name} = $code; |
18 | _install_coderef "${target}::${name}" => "Moo::${name}" => $code; |
19 | } |
20 | |
6c74d087 |
21 | sub import { |
22 | my $target = caller; |
a16d301e |
23 | my $class = shift; |
de3d4906 |
24 | strictures->import; |
1ba11455 |
25 | return if $MAKERS{$target}; # already exported into this package |
108f8ddc |
26 | $MAKERS{$target} = {}; |
27 | _install_tracked $target => extends => sub { |
48a51428 |
28 | $class->_set_superclasses($target, @_); |
6c49212f |
29 | $class->_maybe_reset_handlemoose($target); |
3d49ee27 |
30 | return; |
6c74d087 |
31 | }; |
108f8ddc |
32 | _install_tracked $target => with => sub { |
faa9ce11 |
33 | require Moo::Role; |
6067158c |
34 | Moo::Role->apply_roles_to_package($target, @_); |
6c49212f |
35 | $class->_maybe_reset_handlemoose($target); |
6c74d087 |
36 | }; |
108f8ddc |
37 | _install_tracked $target => has => sub { |
14f32032 |
38 | my ($name, %spec) = @_; |
a16d301e |
39 | $class->_constructor_maker_for($target) |
40 | ->register_attribute_specs($name, \%spec); |
02e9ef74 |
41 | $class->_accessor_maker_for($target) |
42 | ->generate_method($target, $name, \%spec); |
6c49212f |
43 | $class->_maybe_reset_handlemoose($target); |
3d49ee27 |
44 | return; |
14f32032 |
45 | }; |
6c74d087 |
46 | foreach my $type (qw(before after around)) { |
108f8ddc |
47 | _install_tracked $target => $type => sub { |
faa9ce11 |
48 | require Class::Method::Modifiers; |
6c74d087 |
49 | _install_modifier($target, $type, @_); |
3d49ee27 |
50 | return; |
6c74d087 |
51 | }; |
52 | } |
53 | { |
54 | no strict 'refs'; |
55 | @{"${target}::ISA"} = do { |
faa9ce11 |
56 | require Moo::Object; ('Moo::Object'); |
6c74d087 |
57 | } unless @{"${target}::ISA"}; |
58 | } |
3362e41c |
59 | if ($INC{'Moo/HandleMoose.pm'}) { |
60 | Moo::HandleMoose::inject_fake_metaclass_for($target); |
61 | } |
6c74d087 |
62 | } |
63 | |
108f8ddc |
64 | sub unimport { |
65 | my $target = caller; |
66 | _unimport_coderefs($target, $MAKERS{$target}); |
67 | } |
68 | |
48a51428 |
69 | sub _set_superclasses { |
88aaa04a |
70 | my $class = shift; |
71 | my $target = shift; |
72 | for (@_) { |
73 | _load_module($_); |
74 | if ($INC{"Role/Tiny.pm"} && $Role::Tiny::INFO{$_}) { |
75 | require Carp; |
76 | Carp::croak("Can't extend role '$_'"); |
48a51428 |
77 | } |
88aaa04a |
78 | } |
79 | # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA |
80 | @{*{_getglob("${target}::ISA")}{ARRAY}} = @_; |
81 | if (my $old = delete $Moo::MAKERS{$target}{constructor}) { |
82 | delete _getstash($target)->{new}; |
83 | Moo->_constructor_maker_for($target) |
84 | ->register_attribute_specs(%{$old->all_attribute_specs}); |
85 | } |
86 | no warnings 'once'; # piss off. -- mst |
87 | $Moo::HandleMoose::MOUSE{$target} = [ |
88 | grep defined, map Mouse::Util::find_meta($_), @_ |
89 | ] if $INC{"Mouse.pm"}; |
48a51428 |
90 | } |
91 | |
6c49212f |
92 | sub _maybe_reset_handlemoose { |
93 | my ($class, $target) = @_; |
94 | if ($INC{"Moo/HandleMoose.pm"}) { |
95 | Moo::HandleMoose::maybe_reinject_fake_metaclass_for($target); |
96 | } |
97 | } |
98 | |
02e9ef74 |
99 | sub _accessor_maker_for { |
100 | my ($class, $target) = @_; |
101 | return unless $MAKERS{$target}; |
102 | $MAKERS{$target}{accessor} ||= do { |
103 | my $maker_class = do { |
104 | if (my $m = do { |
105 | if (my $defer_target = |
106 | (Sub::Defer::defer_info($target->can('new'))||[])->[0] |
107 | ) { |
108 | my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/); |
109 | $MAKERS{$pkg} && $MAKERS{$pkg}{accessor}; |
110 | } else { |
111 | undef; |
112 | } |
113 | }) { |
114 | ref($m); |
115 | } else { |
116 | require Method::Generate::Accessor; |
117 | 'Method::Generate::Accessor' |
118 | } |
119 | }; |
120 | $maker_class->new; |
121 | } |
122 | } |
123 | |
a16d301e |
124 | sub _constructor_maker_for { |
c4570291 |
125 | my ($class, $target, $select_super) = @_; |
a16d301e |
126 | return unless $MAKERS{$target}; |
127 | $MAKERS{$target}{constructor} ||= do { |
faa9ce11 |
128 | require Method::Generate::Constructor; |
129 | require Sub::Defer; |
c4570291 |
130 | my ($moo_constructor, $con); |
de5c0e53 |
131 | |
c4570291 |
132 | if ($select_super && $MAKERS{$select_super}) { |
133 | $moo_constructor = 1; |
134 | $con = $MAKERS{$select_super}{constructor}; |
135 | } else { |
de5c0e53 |
136 | my $t_new = $target->can('new'); |
c4570291 |
137 | if ($t_new) { |
138 | if ($t_new == Moo::Object->can('new')) { |
139 | $moo_constructor = 1; |
140 | } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) { |
141 | my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/); |
142 | if ($MAKERS{$pkg}) { |
143 | $moo_constructor = 1; |
144 | $con = $MAKERS{$pkg}{constructor}; |
145 | } |
146 | } |
147 | } else { |
148 | $moo_constructor = 1; # no other constructor, make a Moo one |
149 | } |
de5c0e53 |
150 | }; |
02e9ef74 |
151 | ($con ? ref($con) : 'Method::Generate::Constructor') |
a16d301e |
152 | ->new( |
153 | package => $target, |
02e9ef74 |
154 | accessor_generator => $class->_accessor_maker_for($target), |
53875e2c |
155 | construction_string => ( |
156 | $moo_constructor |
157 | ? ($con ? $con->construction_string : undef) |
158 | : ('$class->'.$target.'::SUPER::new(@_)') |
e0e12d16 |
159 | ), |
76ab3977 |
160 | subconstructor_handler => ( |
161 | ' if ($Moo::MAKERS{$class}) {'."\n" |
162 | .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n" |
163 | .' return $class->new(@_)'.";\n" |
346177ba |
164 | .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n" |
165 | .' return $meta->new_object(@_);'."\n" |
76ab3977 |
166 | .' }'."\n" |
e0e12d16 |
167 | ), |
a16d301e |
168 | ) |
169 | ->install_delayed |
de5c0e53 |
170 | ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}}) |
a16d301e |
171 | } |
172 | } |
173 | |
6c74d087 |
174 | 1; |
a17be455 |
175 | =pod |
176 | |
177 | =encoding utf-8 |
8146585e |
178 | |
505f8b7a |
179 | =head1 NAME |
180 | |
181 | Moo - Minimalist Object Orientation (with Moose compatiblity) |
182 | |
8146585e |
183 | =head1 SYNOPSIS |
184 | |
185 | package Cat::Food; |
186 | |
187 | use Moo; |
8146585e |
188 | |
189 | sub feed_lion { |
190 | my $self = shift; |
191 | my $amount = shift || 1; |
192 | |
193 | $self->pounds( $self->pounds - $amount ); |
194 | } |
195 | |
196 | has taste => ( |
197 | is => 'ro', |
198 | ); |
199 | |
200 | has brand => ( |
201 | is => 'ro', |
202 | isa => sub { |
203 | die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ' |
204 | }, |
205 | ); |
206 | |
207 | has pounds => ( |
208 | is => 'rw', |
c9f73a63 |
209 | isa => sub { die "$_[0] is too much cat food!" unless $_[0] < 15 }, |
8146585e |
210 | ); |
211 | |
212 | 1; |
213 | |
52e8f144 |
214 | And elsewhere: |
8146585e |
215 | |
216 | my $full = Cat::Food->new( |
217 | taste => 'DELICIOUS.', |
218 | brand => 'SWEET-TREATZ', |
219 | pounds => 10, |
220 | ); |
221 | |
222 | $full->feed_lion; |
223 | |
224 | say $full->pounds; |
225 | |
226 | =head1 DESCRIPTION |
227 | |
71bd6a81 |
228 | This module is an extremely light-weight subset of L<Moose> optimised for |
52e8f144 |
229 | rapid startup and "pay only for what you use". |
71bd6a81 |
230 | |
8146585e |
231 | It also avoids depending on any XS modules to allow simple deployments. The |
52e8f144 |
232 | name C<Moo> is based on the idea that it provides almost -- but not quite -- two |
8146585e |
233 | thirds of L<Moose>. |
234 | |
52e8f144 |
235 | Unlike L<Mouse> this module does not aim at full compatibility with |
71bd6a81 |
236 | L<Moose>'s surface syntax, preferring instead of provide full interoperability |
237 | via the metaclass inflation capabilites described in L</MOO AND MOOSE>. |
238 | |
239 | For a full list of the minor differences between L<Moose> and L<Moo>'s surface |
240 | syntax, see L</INCOMPATIBILITIES>. |
8146585e |
241 | |
5d5bb71d |
242 | =head1 WHY MOO EXISTS |
243 | |
244 | If you want a full object system with a rich Metaprotocol, L<Moose> is |
245 | already wonderful. |
246 | |
71bd6a81 |
247 | However, sometimes you're writing a command line script or a CGI script |
248 | where fast startup is essential, or code designed to be deployed as a single |
249 | file via L<App::FatPacker>, or you're writing a CPAN module and you want it |
250 | to be usable by people with those constraints. |
251 | |
5d5bb71d |
252 | I've tried several times to use L<Mouse> but it's 3x the size of Moo and |
253 | takes longer to load than most of my Moo based CGI scripts take to run. |
254 | |
255 | If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>, |
52e8f144 |
256 | you want "as little as possible" -- which means "no metaprotocol", which is |
5d5bb71d |
257 | what Moo provides. |
258 | |
71bd6a81 |
259 | Better still, if you install and load L<Moose>, we set up metaclasses for your |
260 | L<Moo> classes and L<Moo::Role> roles, so you can use them in L<Moose> code |
261 | without ever noticing that some of your codebase is using L<Moo>. |
5d5bb71d |
262 | |
52e8f144 |
263 | Hence, Moo exists as its name -- Minimal Object Orientation -- with a pledge |
5d5bb71d |
264 | to make it smooth to upgrade to L<Moose> when you need more than minimal |
265 | features. |
266 | |
71bd6a81 |
267 | =head1 MOO AND MOOSE |
1fce5bc9 |
268 | |
269 | If L<Moo> detects L<Moose> being loaded, it will automatically register |
270 | metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able |
a297a9ab |
271 | to use them in L<Moose> code without anybody ever noticing you aren't using |
1fce5bc9 |
272 | L<Moose> everywhere. |
273 | |
a297a9ab |
274 | Extending a L<Moose> class or consuming a L<Moose::Role> will also work. |
1fce5bc9 |
275 | |
a297a9ab |
276 | So will extending a L<Mouse> class or consuming a L<Mouse::Role> - but note |
277 | that we don't provide L<Mouse> metaclasses or metaroles so the other way |
278 | around doesn't work. This feature exists for L<Any::Moose> users porting to |
52e8f144 |
279 | L<Moo>; enabling L<Mouse> users to use L<Moo> classes is not a priority for us. |
c100c04c |
280 | |
660f3db2 |
281 | This means that there is no need for anything like L<Any::Moose> for Moo |
c100c04c |
282 | code - Moo and Moose code should simply interoperate without problem. To |
283 | handle L<Mouse> code, you'll likely need an empty Moo role or class consuming |
284 | or extending the L<Mouse> stuff since it doesn't register true L<Moose> |
71bd6a81 |
285 | metaclasses like L<Moo> does. |
286 | |
287 | If you want types to be upgraded to the L<Moose> types, use |
288 | L<MooX::Types::MooseLike> and install the L<MooseX::Types> library to |
289 | match the L<MooX::Types::MooseLike> library you're using - L<Moo> will |
290 | load the L<MooseX::Types> library and use that type for the newly created |
291 | metaclass. |
660f3db2 |
292 | |
1fce5bc9 |
293 | If you need to disable the metaclass creation, add: |
294 | |
295 | no Moo::sification; |
296 | |
297 | to your code before Moose is loaded, but bear in mind that this switch is |
a297a9ab |
298 | currently global and turns the mechanism off entirely so don't put this |
299 | in library code. |
1fce5bc9 |
300 | |
c687d016 |
301 | =head1 MOO VERSUS ANY::MOOSE |
302 | |
303 | L<Any::Moose> will load L<Mouse> normally, and L<Moose> in a program using |
304 | L<Moose> - which theoretically allows you to get the startup time of L<Mouse> |
305 | without disadvantaging L<Moose> users. |
306 | |
307 | Sadly, this doesn't entirely work, since the selection is load order dependent |
308 | - L<Moo>'s metaclass inflation system explained above in L</MOO AND MOOSE> is |
309 | significantly more reliable. |
310 | |
311 | So if you want to write a CPAN module that loads fast or has only pure perl |
312 | dependencies but is also fully usable by L<Moose> users, you should be using |
313 | L<Moo>. |
314 | |
315 | For a full explanation, see the article |
316 | L<http://shadow.cat/blog/matt-s-trout/moo-versus-any-moose> which explains |
317 | the differing strategies in more detail and provides a direct example of |
318 | where L<Moo> succeeds and L<Any::Moose> fails. |
319 | |
8146585e |
320 | =head1 IMPORTED METHODS |
321 | |
322 | =head2 new |
323 | |
324 | Foo::Bar->new( attr1 => 3 ); |
325 | |
326 | or |
327 | |
328 | Foo::Bar->new({ attr1 => 3 }); |
329 | |
2e575bcd |
330 | =head2 BUILDARGS |
331 | |
f2eac33e |
332 | sub BUILDARGS { |
a17be455 |
333 | my ( $class, @args ) = @_; |
334 | |
335 | unshift @args, "attr1" if @args % 2 == 1; |
336 | |
f2eac33e |
337 | return { @args }; |
a17be455 |
338 | }; |
339 | |
340 | Foo::Bar->new( 3 ); |
341 | |
342 | The default implementation of this method accepts a hash or hash reference of |
343 | named parameters. If it receives a single argument that isn't a hash reference |
344 | it throws an error. |
345 | |
346 | You can override this method in your class to handle other types of options |
347 | passed to the constructor. |
348 | |
349 | This method should always return a hash reference of named options. |
2e575bcd |
350 | |
2d00f3d6 |
351 | =head2 BUILD |
8146585e |
352 | |
2d00f3d6 |
353 | Define a C<BUILD> method on your class and the constructor will automatically |
354 | call the C<BUILD> method from parent down to child after the object has |
355 | been instantiated. Typically this is used for object validation or possibly |
356 | logging. |
8146585e |
357 | |
2d00f3d6 |
358 | =head2 DEMOLISH |
c2cc003f |
359 | |
debb3fcd |
360 | If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy, |
361 | a C<DESTROY> method is created on first object construction which will call |
c2cc003f |
362 | C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH> |
debb3fcd |
363 | method from child upwards to parents. |
364 | |
365 | Note that the C<DESTROY> method is created on first construction of an object |
366 | of your class in order to not add overhead to classes without C<DEMOLISH> |
367 | methods; this may prove slightly surprising if you try and define your own. |
c2cc003f |
368 | |
8146585e |
369 | =head2 does |
370 | |
371 | if ($foo->does('Some::Role1')) { |
372 | ... |
373 | } |
374 | |
375 | Returns true if the object composes in the passed role. |
376 | |
377 | =head1 IMPORTED SUBROUTINES |
378 | |
379 | =head2 extends |
380 | |
381 | extends 'Parent::Class'; |
382 | |
2e575bcd |
383 | Declares base class. Multiple superclasses can be passed for multiple |
384 | inheritance (but please use roles instead). |
385 | |
386 | Calling extends more than once will REPLACE your superclasses, not add to |
387 | them like 'use base' would. |
8146585e |
388 | |
389 | =head2 with |
390 | |
391 | with 'Some::Role1'; |
8146585e |
392 | |
f9755246 |
393 | or |
394 | |
395 | with 'Some::Role1', 'Some::Role2'; |
396 | |
397 | Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current |
398 | class. An error will be raised if these roles have conflicting methods. |
8146585e |
399 | |
400 | =head2 has |
401 | |
402 | has attr => ( |
403 | is => 'ro', |
404 | ); |
405 | |
406 | Declares an attribute for the class. |
407 | |
408 | The options for C<has> are as follows: |
409 | |
410 | =over 2 |
411 | |
412 | =item * is |
413 | |
6577509a |
414 | B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>. |
71db76ce |
415 | |
416 | C<ro> generates an accessor that dies if you attempt to write to it - i.e. |
417 | a getter only - by defaulting C<reader> to the name of the attribute. |
418 | |
71db76ce |
419 | C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and |
420 | C<builder> to C<_build_${attribute_name}> to allow on-demand generated |
421 | attributes. This feature was my attempt to fix my incompetence when |
422 | originally designing C<lazy_build>, and is also implemented by |
423 | L<MooseX::AttributeShortcuts>. |
424 | |
425 | C<rwp> generates a reader like C<ro>, but also sets C<writer> to |
426 | C<_set_${attribute_name}> for attributes that are designed to be written |
427 | from inside of the class, but read-only from outside. |
428 | This feature comes from L<MooseX::AttributeShortcuts>. |
8146585e |
429 | |
6577509a |
430 | C<rw> generates a normal getter/setter by defaulting C<accessor> to the |
431 | name of the attribute. |
432 | |
8146585e |
433 | =item * isa |
434 | |
52e8f144 |
435 | Takes a coderef which is meant to validate the attribute. Unlike L<Moose>, Moo |
8146585e |
436 | does not include a basic type system, so instead of doing C<< isa => 'Num' >>, |
437 | one should do |
438 | |
c9f73a63 |
439 | isa => sub { |
8146585e |
440 | die "$_[0] is not a number!" unless looks_like_number $_[0] |
441 | }, |
442 | |
443 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
444 | |
c4074652 |
445 | Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion |
446 | subroutine has been supplied, C<isa> checks are not structural to your code |
447 | and can, if desired, be omitted on non-debug builds (although if this results |
448 | in an uncaught bug causing your program to break, the L<Moo> authors guarantee |
449 | nothing except that you get to keep both halves). |
450 | |
71db76ce |
451 | If you want L<MooseX::Types> style named types, look at |
452 | L<MooX::Types::MooseLike>. |
453 | |
454 | To cause your C<isa> entries to be automatically mapped to named |
455 | L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour |
456 | of creating an anonymous type), set: |
457 | |
458 | $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub { |
459 | require MooseX::Types::Something; |
460 | return MooseX::Types::Something::TypeName(); |
461 | }; |
462 | |
463 | Note that this example is purely illustrative; anything that returns a |
464 | L<Moose::Meta::TypeConstraint> object or something similar enough to it to |
465 | make L<Moose> happy is fine. |
466 | |
8146585e |
467 | =item * coerce |
468 | |
469 | Takes a coderef which is meant to coerce the attribute. The basic idea is to |
470 | do something like the following: |
471 | |
c9f73a63 |
472 | coerce => sub { |
8146585e |
473 | $_[0] + 1 unless $_[0] % 2 |
474 | }, |
475 | |
52e8f144 |
476 | Note that L<Moo> will always fire your coercion: this is to permit |
477 | C<isa> entries to be used purely for bug trapping, whereas coercions are |
c4074652 |
478 | always structural to your code. We do, however, apply any supplied C<isa> |
479 | check after the coercion has run to ensure that it returned a valid value. |
8146585e |
480 | |
23a3e34e |
481 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
2e575bcd |
482 | |
e1efec09 |
483 | =item * handles |
484 | |
485 | Takes a string |
486 | |
69673ca7 |
487 | handles => 'RobotRole' |
488 | |
489 | Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which |
490 | becomes the list of methods to handle. |
e1efec09 |
491 | |
492 | Takes a list of methods |
493 | |
494 | handles => [ qw( one two ) ] |
495 | |
496 | Takes a hashref |
497 | |
498 | handles => { |
499 | un => 'one', |
500 | } |
501 | |
8146585e |
502 | =item * trigger |
503 | |
6fe5100d |
504 | Takes a coderef which will get called any time the attribute is set. This |
505 | includes the constructor. Coderef will be invoked against the object with the |
506 | new value as an argument. |
8146585e |
507 | |
71db76ce |
508 | If you set this to just C<1>, it generates a trigger which calls the |
509 | C<_trigger_${attr_name}> method on C<$self>. This feature comes from |
510 | L<MooseX::AttributeShortcuts>. |
511 | |
2e575bcd |
512 | Note that Moose also passes the old value, if any; this feature is not yet |
513 | supported. |
514 | |
8146585e |
515 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
516 | |
52e8f144 |
517 | =item * C<default> |
8146585e |
518 | |
2e575bcd |
519 | Takes a coderef which will get called with $self as its only argument |
520 | to populate an attribute if no value is supplied to the constructor - or |
521 | if the attribute is lazy, when the attribute is first retrieved if no |
522 | value has yet been provided. |
523 | |
524 | Note that if your default is fired during new() there is no guarantee that |
525 | other attributes have been populated yet so you should not rely on their |
526 | existence. |
8146585e |
527 | |
528 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
529 | |
52e8f144 |
530 | =item * C<predicate> |
8146585e |
531 | |
2e575bcd |
532 | Takes a method name which will return true if an attribute has a value. |
8146585e |
533 | |
71db76ce |
534 | If you set this to just C<1>, the predicate is automatically named |
535 | C<has_${attr_name}> if your attribute's name does not start with an |
536 | underscore, or <_has_${attr_name_without_the_underscore}> if it does. |
537 | This feature comes from L<MooseX::AttributeShortcuts>. |
8146585e |
538 | |
52e8f144 |
539 | =item * C<builder> |
8146585e |
540 | |
2e575bcd |
541 | Takes a method name which will be called to create the attribute - functions |
542 | exactly like default except that instead of calling |
543 | |
544 | $default->($self); |
545 | |
546 | Moo will call |
547 | |
548 | $self->$builder; |
8146585e |
549 | |
71db76ce |
550 | If you set this to just C<1>, the predicate is automatically named |
551 | C<_build_${attr_name}>. This feature comes from L<MooseX::AttributeShortcuts>. |
552 | |
52e8f144 |
553 | =item * C<clearer> |
8146585e |
554 | |
555 | Takes a method name which will clear the attribute. |
556 | |
71db76ce |
557 | If you set this to just C<1>, the clearer is automatically named |
558 | C<clear_${attr_name}> if your attribute's name does not start with an |
559 | underscore, or <_clear_${attr_name_without_the_underscore}> if it does. |
560 | This feature comes from L<MooseX::AttributeShortcuts>. |
561 | |
52e8f144 |
562 | =item * C<lazy> |
8146585e |
563 | |
564 | B<Boolean>. Set this if you want values for the attribute to be grabbed |
565 | lazily. This is usually a good idea if you have a L</builder> which requires |
566 | another attribute to be set. |
567 | |
52e8f144 |
568 | =item * C<required> |
8146585e |
569 | |
570 | B<Boolean>. Set this if the attribute must be passed on instantiation. |
571 | |
52e8f144 |
572 | =item * C<reader> |
1eba910c |
573 | |
574 | The value of this attribute will be the name of the method to get the value of |
575 | the attribute. If you like Java style methods, you might set this to |
576 | C<get_foo> |
577 | |
52e8f144 |
578 | =item * C<writer> |
1eba910c |
579 | |
580 | The value of this attribute will be the name of the method to set the value of |
581 | the attribute. If you like Java style methods, you might set this to |
52e8f144 |
582 | C<set_foo>. |
1eba910c |
583 | |
52e8f144 |
584 | =item * C<weak_ref> |
8146585e |
585 | |
586 | B<Boolean>. Set this if you want the reference that the attribute contains to |
587 | be weakened; use this when circular references are possible, which will cause |
588 | leaks. |
589 | |
52e8f144 |
590 | =item * C<init_arg> |
8146585e |
591 | |
592 | Takes the name of the key to look for at instantiation time of the object. A |
593 | common use of this is to make an underscored attribute have a non-underscored |
594 | initialization name. C<undef> means that passing the value in on instantiation |
71db76ce |
595 | is ignored. |
8146585e |
596 | |
597 | =back |
598 | |
599 | =head2 before |
600 | |
601 | before foo => sub { ... }; |
602 | |
603 | See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full |
604 | documentation. |
605 | |
606 | =head2 around |
607 | |
608 | around foo => sub { ... }; |
609 | |
610 | See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full |
611 | documentation. |
612 | |
613 | =head2 after |
614 | |
615 | after foo => sub { ... }; |
616 | |
617 | See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full |
618 | documentation. |
619 | |
8146585e |
620 | =head1 SUB QUOTE AWARE |
621 | |
622 | L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable," |
623 | giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote> |
624 | aware can take advantage of this. |
625 | |
c9f73a63 |
626 | To do this, you can write |
627 | |
628 | use Moo; |
629 | use Sub::Quote; |
630 | |
631 | has foo => ( |
3b4a915a |
632 | is => 'ro', |
633 | isa => quote_sub(q{ die "Not <3" unless $_[0] < 3 }) |
c9f73a63 |
634 | ); |
635 | |
636 | which will be inlined as |
637 | |
638 | do { |
639 | local @_ = ($_[0]->{foo}); |
640 | die "Not <3" unless $_[0] < 3; |
641 | } |
642 | |
643 | or to avoid localizing @_, |
644 | |
645 | has foo => ( |
3b4a915a |
646 | is => 'ro', |
647 | isa => quote_sub(q{ my ($val) = @_; die "Not <3" unless $val < 3 }) |
c9f73a63 |
648 | ); |
649 | |
650 | which will be inlined as |
651 | |
652 | do { |
653 | my ($val) = ($_[0]->{foo}); |
654 | die "Not <3" unless $val < 3; |
655 | } |
656 | |
657 | See L<Sub::Quote> for more information, including how to pass lexical |
52e8f144 |
658 | captures that will also be compiled into the subroutine. |
c9f73a63 |
659 | |
2e575bcd |
660 | =head1 INCOMPATIBILITIES WITH MOOSE |
8146585e |
661 | |
52e8f144 |
662 | There is no built-in type system. C<isa> is verified with a coderef; if you |
8146585e |
663 | need complex types, just make a library of coderefs, or better yet, functions |
5902c1fc |
664 | that return quoted subs. L<MooX::Types::MooseLike> provides a similar API |
665 | to L<MooseX::Types::Moose> so that you can write |
666 | |
667 | has days_to_live => (is => 'ro', isa => Int); |
668 | |
669 | and have it work with both; it is hoped that providing only subrefs as an |
670 | API will encourage the use of other type systems as well, since it's |
671 | probably the weakest part of Moose design-wise. |
8146585e |
672 | |
2e575bcd |
673 | C<initializer> is not supported in core since the author considers it to be a |
f88623a1 |
674 | bad idea but may be supported by an extension in future. Meanwhile C<trigger> or |
675 | C<coerce> are more likely to be able to fulfill your needs. |
8146585e |
676 | |
677 | There is no meta object. If you need this level of complexity you wanted |
2e575bcd |
678 | L<Moose> - Moo succeeds at being small because it explicitly does not |
f9755246 |
679 | provide a metaprotocol. However, if you load L<Moose>, then |
680 | |
681 | Class::MOP::class_of($moo_class_or_role) |
682 | |
683 | will return an appropriate metaclass pre-populated by L<Moo>. |
8146585e |
684 | |
13e41b70 |
685 | No support for C<super>, C<override>, C<inner>, or C<augment> - the author |
686 | considers augment to be a bad idea, and override can be translated: |
687 | |
688 | override foo => sub { |
689 | ... |
690 | super(); |
691 | ... |
692 | }; |
693 | |
694 | around foo => sub { |
695 | my ($orig, $self) = (shift, shift); |
696 | ... |
697 | $self->$orig(@_); |
698 | ... |
699 | }; |
8146585e |
700 | |
f2eac33e |
701 | The C<dump> method is not provided by default. The author suggests loading |
c96a6326 |
702 | L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and |
703 | using C<$obj-E<gt>$::Dwarn()> instead. |
704 | |
8146585e |
705 | L</default> only supports coderefs, because doing otherwise is usually a |
706 | mistake anyway. |
707 | |
f9755246 |
708 | C<lazy_build> is not supported; you are instead encouraged to use the |
52e8f144 |
709 | C<< is => 'lazy' >> option supported by L<Moo> and L<MooseX::AttributeShortcuts>. |
8146585e |
710 | |
2e575bcd |
711 | C<auto_deref> is not supported since the author considers it a bad idea. |
8146585e |
712 | |
f9755246 |
713 | C<documentation> will show up in a L<Moose> metaclass created from your class |
c4074652 |
714 | but is otherwise ignored. Then again, L<Moose> ignores it as well, so this |
f9755246 |
715 | is arguably not an incompatibility. |
40f3e3aa |
716 | |
c4074652 |
717 | Since C<coerce> does not require C<isa> to be defined but L<Moose> does |
52e8f144 |
718 | require it, the metaclass inflation for coerce alone is a trifle insane |
c4074652 |
719 | and if you attempt to subtype the result will almost certainly break. |
720 | |
69673ca7 |
721 | Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest |
722 | similar invocation for L<Moose> would be: |
723 | |
724 | use Moose; |
725 | use warnings FATAL => "all"; |
726 | |
727 | Additionally, L<Moo> supports a set of attribute option shortcuts intended to |
728 | reduce common boilerplate. The set of shortcuts is the same as in the L<Moose> |
239d4711 |
729 | module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you: |
69673ca7 |
730 | |
731 | package MyClass; |
732 | use Moo; |
733 | |
734 | The nearest L<Moose> invocation would be: |
735 | |
736 | package MyClass; |
737 | |
738 | use Moose; |
739 | use warnings FATAL => "all"; |
740 | use MooseX::AttributeShortcuts; |
741 | |
5902c1fc |
742 | or, if you're inheriting from a non-Moose class, |
743 | |
744 | package MyClass; |
745 | |
746 | use Moose; |
747 | use MooseX::NonMoose; |
748 | use warnings FATAL => "all"; |
749 | use MooseX::AttributeShortcuts; |
750 | |
751 | Finally, Moose requires you to call |
752 | |
753 | __PACKAGE__->meta->make_immutable; |
754 | |
755 | at the end of your class to get an inlined (i.e. not horribly slow) |
756 | constructor. Moo does it automatically the first time ->new is called |
757 | on your class. |
758 | |
660f3db2 |
759 | =head1 SUPPORT |
760 | |
9836a6ee |
761 | Users' IRC: #moose on irc.perl.org |
762 | |
763 | Development and contribution IRC: #web-simple on irc.perl.org |
660f3db2 |
764 | |
40f3e3aa |
765 | =head1 AUTHOR |
766 | |
767 | mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk> |
768 | |
769 | =head1 CONTRIBUTORS |
770 | |
5da684a2 |
771 | dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx> |
772 | |
773 | frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com> |
774 | |
775 | hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org> |
776 | |
777 | jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com> |
778 | |
779 | ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org> |
40f3e3aa |
780 | |
11f7a042 |
781 | chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com> |
782 | |
a17be455 |
783 | ajgb - Alex J. G. Burzyński (cpan:AJGB) <ajgb@cpan.org> |
784 | |
7b8177f8 |
785 | doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net> |
786 | |
1fb2de92 |
787 | perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org> |
788 | |
3202e039 |
789 | Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com> |
790 | |
e355471c |
791 | ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org> |
792 | |
40f3e3aa |
793 | =head1 COPYRIGHT |
794 | |
a958e36d |
795 | Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS> |
40f3e3aa |
796 | as listed above. |
797 | |
798 | =head1 LICENSE |
799 | |
800 | This library is free software and may be distributed under the same terms |
801 | as perl itself. |
802 | |
803 | =cut |