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 | |
013a2be3 |
8 | our $VERSION = '1.003000'; |
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 $class = shift; |
de3d4906 |
24 | strictures->import; |
c3736593 |
25 | if ($Role::Tiny::INFO{$target} and $Role::Tiny::INFO{$target}{is_role}) { |
1791ba32 |
26 | die "Cannot import Moo into a role"; |
27 | } |
fa93bfb2 |
28 | $MAKERS{$target} ||= {}; |
108f8ddc |
29 | _install_tracked $target => extends => sub { |
48a51428 |
30 | $class->_set_superclasses($target, @_); |
6c49212f |
31 | $class->_maybe_reset_handlemoose($target); |
3d49ee27 |
32 | return; |
6c74d087 |
33 | }; |
108f8ddc |
34 | _install_tracked $target => with => sub { |
faa9ce11 |
35 | require Moo::Role; |
6067158c |
36 | Moo::Role->apply_roles_to_package($target, @_); |
6c49212f |
37 | $class->_maybe_reset_handlemoose($target); |
6c74d087 |
38 | }; |
108f8ddc |
39 | _install_tracked $target => has => sub { |
bf0e0d7a |
40 | my $name_proto = shift; |
41 | my @name_proto = ref $name_proto eq 'ARRAY' ? @$name_proto : $name_proto; |
42 | if (@_ % 2 != 0) { |
43 | require Carp; |
44 | Carp::croak("Invalid options for " . join(', ', map "'$_'", @name_proto) |
45 | . " attribute(s): even number of arguments expected, got " . scalar @_) |
46 | } |
47 | my %spec = @_; |
48 | foreach my $name (@name_proto) { |
49 | # Note that when multiple attributes specified, each attribute |
1d17c7c1 |
50 | # needs a separate \%specs hashref |
bf0e0d7a |
51 | my $spec_ref = @name_proto > 1 ? +{%spec} : \%spec; |
1d17c7c1 |
52 | $class->_constructor_maker_for($target) |
53 | ->register_attribute_specs($name, $spec_ref); |
54 | $class->_accessor_maker_for($target) |
55 | ->generate_method($target, $name, $spec_ref); |
56 | $class->_maybe_reset_handlemoose($target); |
57 | } |
3d49ee27 |
58 | return; |
14f32032 |
59 | }; |
6c74d087 |
60 | foreach my $type (qw(before after around)) { |
108f8ddc |
61 | _install_tracked $target => $type => sub { |
faa9ce11 |
62 | require Class::Method::Modifiers; |
6c74d087 |
63 | _install_modifier($target, $type, @_); |
3d49ee27 |
64 | return; |
6c74d087 |
65 | }; |
66 | } |
fa93bfb2 |
67 | return if $MAKERS{$target}{is_class}; # already exported into this package |
68 | $MAKERS{$target}{is_class} = 1; |
6c74d087 |
69 | { |
70 | no strict 'refs'; |
71 | @{"${target}::ISA"} = do { |
faa9ce11 |
72 | require Moo::Object; ('Moo::Object'); |
6c74d087 |
73 | } unless @{"${target}::ISA"}; |
74 | } |
3362e41c |
75 | if ($INC{'Moo/HandleMoose.pm'}) { |
76 | Moo::HandleMoose::inject_fake_metaclass_for($target); |
77 | } |
6c74d087 |
78 | } |
79 | |
108f8ddc |
80 | sub unimport { |
81 | my $target = caller; |
82 | _unimport_coderefs($target, $MAKERS{$target}); |
83 | } |
84 | |
48a51428 |
85 | sub _set_superclasses { |
88aaa04a |
86 | my $class = shift; |
87 | my $target = shift; |
141b507a |
88 | foreach my $superclass (@_) { |
89 | _load_module($superclass); |
90 | if ($INC{"Role/Tiny.pm"} && $Role::Tiny::INFO{$superclass}) { |
88aaa04a |
91 | require Carp; |
141b507a |
92 | Carp::croak("Can't extend role '$superclass'"); |
48a51428 |
93 | } |
88aaa04a |
94 | } |
95 | # Can't do *{...} = \@_ or 5.10.0's mro.pm stops seeing @ISA |
96 | @{*{_getglob("${target}::ISA")}{ARRAY}} = @_; |
97 | if (my $old = delete $Moo::MAKERS{$target}{constructor}) { |
98 | delete _getstash($target)->{new}; |
99 | Moo->_constructor_maker_for($target) |
100 | ->register_attribute_specs(%{$old->all_attribute_specs}); |
101 | } |
85de1ef9 |
102 | elsif (!$target->isa('Moo::Object')) { |
103 | Moo->_constructor_maker_for($target); |
104 | } |
88aaa04a |
105 | no warnings 'once'; # piss off. -- mst |
106 | $Moo::HandleMoose::MOUSE{$target} = [ |
107 | grep defined, map Mouse::Util::find_meta($_), @_ |
96b09f21 |
108 | ] if Mouse::Util->can('find_meta'); |
48a51428 |
109 | } |
110 | |
6c49212f |
111 | sub _maybe_reset_handlemoose { |
112 | my ($class, $target) = @_; |
113 | if ($INC{"Moo/HandleMoose.pm"}) { |
114 | Moo::HandleMoose::maybe_reinject_fake_metaclass_for($target); |
115 | } |
116 | } |
117 | |
02e9ef74 |
118 | sub _accessor_maker_for { |
119 | my ($class, $target) = @_; |
120 | return unless $MAKERS{$target}; |
121 | $MAKERS{$target}{accessor} ||= do { |
122 | my $maker_class = do { |
123 | if (my $m = do { |
124 | if (my $defer_target = |
125 | (Sub::Defer::defer_info($target->can('new'))||[])->[0] |
126 | ) { |
127 | my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/); |
128 | $MAKERS{$pkg} && $MAKERS{$pkg}{accessor}; |
129 | } else { |
130 | undef; |
131 | } |
132 | }) { |
133 | ref($m); |
134 | } else { |
135 | require Method::Generate::Accessor; |
136 | 'Method::Generate::Accessor' |
137 | } |
138 | }; |
139 | $maker_class->new; |
140 | } |
141 | } |
142 | |
a16d301e |
143 | sub _constructor_maker_for { |
8dee08c1 |
144 | my ($class, $target) = @_; |
a16d301e |
145 | return unless $MAKERS{$target}; |
146 | $MAKERS{$target}{constructor} ||= do { |
faa9ce11 |
147 | require Method::Generate::Constructor; |
148 | require Sub::Defer; |
c4570291 |
149 | my ($moo_constructor, $con); |
de5c0e53 |
150 | |
8dee08c1 |
151 | my $t_new = $target->can('new'); |
152 | if ($t_new) { |
153 | if ($t_new == Moo::Object->can('new')) { |
154 | $moo_constructor = 1; |
155 | } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) { |
156 | my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/); |
157 | if ($MAKERS{$pkg}) { |
c4570291 |
158 | $moo_constructor = 1; |
8dee08c1 |
159 | $con = $MAKERS{$pkg}{constructor}; |
c4570291 |
160 | } |
c4570291 |
161 | } |
8dee08c1 |
162 | } else { |
163 | $moo_constructor = 1; # no other constructor, make a Moo one |
164 | } |
02e9ef74 |
165 | ($con ? ref($con) : 'Method::Generate::Constructor') |
a16d301e |
166 | ->new( |
167 | package => $target, |
02e9ef74 |
168 | accessor_generator => $class->_accessor_maker_for($target), |
53875e2c |
169 | construction_string => ( |
170 | $moo_constructor |
171 | ? ($con ? $con->construction_string : undef) |
e963cc96 |
172 | : ('$class->'.$target.'::SUPER::new($class->can(q[FOREIGNBUILDARGS]) ? $class->FOREIGNBUILDARGS(@_) : @_)') |
e0e12d16 |
173 | ), |
76ab3977 |
174 | subconstructor_handler => ( |
175 | ' if ($Moo::MAKERS{$class}) {'."\n" |
176 | .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n" |
177 | .' return $class->new(@_)'.";\n" |
346177ba |
178 | .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n" |
eea41fb2 |
179 | .' return $meta->new_object($class->BUILDARGS(@_));'."\n" |
76ab3977 |
180 | .' }'."\n" |
e0e12d16 |
181 | ), |
a16d301e |
182 | ) |
183 | ->install_delayed |
de5c0e53 |
184 | ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}}) |
a16d301e |
185 | } |
186 | } |
187 | |
6c74d087 |
188 | 1; |
a17be455 |
189 | =pod |
190 | |
191 | =encoding utf-8 |
8146585e |
192 | |
505f8b7a |
193 | =head1 NAME |
194 | |
c1c6bd6d |
195 | Moo - Minimalist Object Orientation (with Moose compatibility) |
505f8b7a |
196 | |
8146585e |
197 | =head1 SYNOPSIS |
198 | |
199 | package Cat::Food; |
200 | |
201 | use Moo; |
8146585e |
202 | |
203 | sub feed_lion { |
204 | my $self = shift; |
205 | my $amount = shift || 1; |
206 | |
207 | $self->pounds( $self->pounds - $amount ); |
208 | } |
209 | |
210 | has taste => ( |
211 | is => 'ro', |
212 | ); |
213 | |
214 | has brand => ( |
215 | is => 'ro', |
216 | isa => sub { |
217 | die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ' |
218 | }, |
16382e05 |
219 | ); |
8146585e |
220 | |
221 | has pounds => ( |
222 | is => 'rw', |
c9f73a63 |
223 | isa => sub { die "$_[0] is too much cat food!" unless $_[0] < 15 }, |
8146585e |
224 | ); |
225 | |
226 | 1; |
227 | |
52e8f144 |
228 | And elsewhere: |
8146585e |
229 | |
230 | my $full = Cat::Food->new( |
231 | taste => 'DELICIOUS.', |
232 | brand => 'SWEET-TREATZ', |
233 | pounds => 10, |
234 | ); |
235 | |
236 | $full->feed_lion; |
237 | |
238 | say $full->pounds; |
239 | |
240 | =head1 DESCRIPTION |
241 | |
71bd6a81 |
242 | This module is an extremely light-weight subset of L<Moose> optimised for |
52e8f144 |
243 | rapid startup and "pay only for what you use". |
71bd6a81 |
244 | |
8146585e |
245 | It also avoids depending on any XS modules to allow simple deployments. The |
52e8f144 |
246 | name C<Moo> is based on the idea that it provides almost -- but not quite -- two |
8146585e |
247 | thirds of L<Moose>. |
248 | |
52e8f144 |
249 | Unlike L<Mouse> this module does not aim at full compatibility with |
71bd6a81 |
250 | L<Moose>'s surface syntax, preferring instead of provide full interoperability |
5f0ba39b |
251 | via the metaclass inflation capabilities described in L</MOO AND MOOSE>. |
71bd6a81 |
252 | |
253 | For a full list of the minor differences between L<Moose> and L<Moo>'s surface |
21717718 |
254 | syntax, see L</INCOMPATIBILITIES WITH MOOSE>. |
8146585e |
255 | |
5d5bb71d |
256 | =head1 WHY MOO EXISTS |
257 | |
258 | If you want a full object system with a rich Metaprotocol, L<Moose> is |
259 | already wonderful. |
260 | |
71bd6a81 |
261 | However, sometimes you're writing a command line script or a CGI script |
262 | where fast startup is essential, or code designed to be deployed as a single |
263 | file via L<App::FatPacker>, or you're writing a CPAN module and you want it |
264 | to be usable by people with those constraints. |
265 | |
5d5bb71d |
266 | I've tried several times to use L<Mouse> but it's 3x the size of Moo and |
267 | takes longer to load than most of my Moo based CGI scripts take to run. |
268 | |
269 | If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>, |
52e8f144 |
270 | you want "as little as possible" -- which means "no metaprotocol", which is |
5d5bb71d |
271 | what Moo provides. |
272 | |
71bd6a81 |
273 | Better still, if you install and load L<Moose>, we set up metaclasses for your |
274 | L<Moo> classes and L<Moo::Role> roles, so you can use them in L<Moose> code |
275 | without ever noticing that some of your codebase is using L<Moo>. |
5d5bb71d |
276 | |
52e8f144 |
277 | Hence, Moo exists as its name -- Minimal Object Orientation -- with a pledge |
5d5bb71d |
278 | to make it smooth to upgrade to L<Moose> when you need more than minimal |
279 | features. |
280 | |
71bd6a81 |
281 | =head1 MOO AND MOOSE |
1fce5bc9 |
282 | |
283 | If L<Moo> detects L<Moose> being loaded, it will automatically register |
284 | metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able |
a297a9ab |
285 | to use them in L<Moose> code without anybody ever noticing you aren't using |
1fce5bc9 |
286 | L<Moose> everywhere. |
287 | |
9a3fc505 |
288 | L<Moo> will also create L<Moose type constraints|Moose::Manual::Types> for |
289 | classes and roles, so that C<< isa => 'MyClass' >> and C<< isa => 'MyRole' >> |
290 | work the same as for L<Moose> classes and roles. |
291 | |
a297a9ab |
292 | Extending a L<Moose> class or consuming a L<Moose::Role> will also work. |
1fce5bc9 |
293 | |
a297a9ab |
294 | So will extending a L<Mouse> class or consuming a L<Mouse::Role> - but note |
295 | that we don't provide L<Mouse> metaclasses or metaroles so the other way |
296 | around doesn't work. This feature exists for L<Any::Moose> users porting to |
52e8f144 |
297 | L<Moo>; enabling L<Mouse> users to use L<Moo> classes is not a priority for us. |
c100c04c |
298 | |
660f3db2 |
299 | This means that there is no need for anything like L<Any::Moose> for Moo |
c100c04c |
300 | code - Moo and Moose code should simply interoperate without problem. To |
301 | handle L<Mouse> code, you'll likely need an empty Moo role or class consuming |
302 | or extending the L<Mouse> stuff since it doesn't register true L<Moose> |
71bd6a81 |
303 | metaclasses like L<Moo> does. |
304 | |
305 | If you want types to be upgraded to the L<Moose> types, use |
306 | L<MooX::Types::MooseLike> and install the L<MooseX::Types> library to |
307 | match the L<MooX::Types::MooseLike> library you're using - L<Moo> will |
308 | load the L<MooseX::Types> library and use that type for the newly created |
309 | metaclass. |
660f3db2 |
310 | |
1fce5bc9 |
311 | If you need to disable the metaclass creation, add: |
312 | |
313 | no Moo::sification; |
314 | |
315 | to your code before Moose is loaded, but bear in mind that this switch is |
a297a9ab |
316 | currently global and turns the mechanism off entirely so don't put this |
317 | in library code. |
1fce5bc9 |
318 | |
dcbfe1d9 |
319 | =head1 MOO AND CLASS::XSACCESSOR |
320 | |
321 | If a new enough version of L<Class::XSAccessor> is available, it |
322 | will be used to generate simple accessors, readers, and writers for |
323 | a speed boost. Simple accessors are those without lazy defaults, |
324 | type checks/coercions, or triggers. Readers and writers generated |
325 | by L<Class::XSAccessor> will behave slightly differently: they will |
326 | reject attempts to call them with the incorrect number of parameters. |
327 | |
c687d016 |
328 | =head1 MOO VERSUS ANY::MOOSE |
329 | |
330 | L<Any::Moose> will load L<Mouse> normally, and L<Moose> in a program using |
331 | L<Moose> - which theoretically allows you to get the startup time of L<Mouse> |
332 | without disadvantaging L<Moose> users. |
333 | |
334 | Sadly, this doesn't entirely work, since the selection is load order dependent |
335 | - L<Moo>'s metaclass inflation system explained above in L</MOO AND MOOSE> is |
336 | significantly more reliable. |
337 | |
338 | So if you want to write a CPAN module that loads fast or has only pure perl |
339 | dependencies but is also fully usable by L<Moose> users, you should be using |
340 | L<Moo>. |
341 | |
342 | For a full explanation, see the article |
343 | L<http://shadow.cat/blog/matt-s-trout/moo-versus-any-moose> which explains |
344 | the differing strategies in more detail and provides a direct example of |
345 | where L<Moo> succeeds and L<Any::Moose> fails. |
346 | |
8146585e |
347 | =head1 IMPORTED METHODS |
348 | |
349 | =head2 new |
350 | |
351 | Foo::Bar->new( attr1 => 3 ); |
352 | |
353 | or |
354 | |
355 | Foo::Bar->new({ attr1 => 3 }); |
356 | |
2e575bcd |
357 | =head2 BUILDARGS |
358 | |
f2eac33e |
359 | sub BUILDARGS { |
a17be455 |
360 | my ( $class, @args ) = @_; |
361 | |
362 | unshift @args, "attr1" if @args % 2 == 1; |
363 | |
f2eac33e |
364 | return { @args }; |
a17be455 |
365 | }; |
366 | |
367 | Foo::Bar->new( 3 ); |
368 | |
369 | The default implementation of this method accepts a hash or hash reference of |
370 | named parameters. If it receives a single argument that isn't a hash reference |
371 | it throws an error. |
372 | |
373 | You can override this method in your class to handle other types of options |
374 | passed to the constructor. |
375 | |
376 | This method should always return a hash reference of named options. |
2e575bcd |
377 | |
76a0beff |
378 | =head2 FOREIGNBUILDARGS |
379 | |
380 | If you are inheriting from a non-Moo class, the arguments passed to the parent |
381 | class constructor can be manipulated by defining a C<FOREIGNBUILDARGS> method. |
416bcb6c |
382 | It will receive the same arguments as C<BUILDARGS>, and should return a list |
76a0beff |
383 | of arguments to pass to the parent class constructor. |
384 | |
2d00f3d6 |
385 | =head2 BUILD |
8146585e |
386 | |
2d00f3d6 |
387 | Define a C<BUILD> method on your class and the constructor will automatically |
388 | call the C<BUILD> method from parent down to child after the object has |
389 | been instantiated. Typically this is used for object validation or possibly |
390 | logging. |
8146585e |
391 | |
2d00f3d6 |
392 | =head2 DEMOLISH |
c2cc003f |
393 | |
debb3fcd |
394 | If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy, |
395 | a C<DESTROY> method is created on first object construction which will call |
c2cc003f |
396 | C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH> |
debb3fcd |
397 | method from child upwards to parents. |
398 | |
399 | Note that the C<DESTROY> method is created on first construction of an object |
400 | of your class in order to not add overhead to classes without C<DEMOLISH> |
401 | methods; this may prove slightly surprising if you try and define your own. |
c2cc003f |
402 | |
8146585e |
403 | =head2 does |
404 | |
405 | if ($foo->does('Some::Role1')) { |
406 | ... |
407 | } |
408 | |
409 | Returns true if the object composes in the passed role. |
410 | |
411 | =head1 IMPORTED SUBROUTINES |
412 | |
413 | =head2 extends |
414 | |
415 | extends 'Parent::Class'; |
416 | |
2e575bcd |
417 | Declares base class. Multiple superclasses can be passed for multiple |
418 | inheritance (but please use roles instead). |
419 | |
420 | Calling extends more than once will REPLACE your superclasses, not add to |
421 | them like 'use base' would. |
8146585e |
422 | |
423 | =head2 with |
424 | |
425 | with 'Some::Role1'; |
8146585e |
426 | |
f9755246 |
427 | or |
428 | |
429 | with 'Some::Role1', 'Some::Role2'; |
430 | |
431 | Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current |
432 | class. An error will be raised if these roles have conflicting methods. |
8146585e |
433 | |
434 | =head2 has |
435 | |
436 | has attr => ( |
437 | is => 'ro', |
438 | ); |
439 | |
440 | Declares an attribute for the class. |
441 | |
1c9916fa |
442 | package Foo; |
443 | use Moo; |
444 | has 'attr' => ( |
445 | is => 'ro' |
446 | ); |
d56136b9 |
447 | |
1c9916fa |
448 | package Bar; |
449 | use Moo; |
450 | extends 'Foo'; |
d56136b9 |
451 | has '+attr' => ( |
452 | default => sub { "blah" }, |
453 | ); |
454 | |
455 | Using the C<+> notation, it's possible to override an attribute. |
456 | |
8146585e |
457 | The options for C<has> are as follows: |
458 | |
459 | =over 2 |
460 | |
461 | =item * is |
462 | |
6577509a |
463 | B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>. |
71db76ce |
464 | |
465 | C<ro> generates an accessor that dies if you attempt to write to it - i.e. |
466 | a getter only - by defaulting C<reader> to the name of the attribute. |
467 | |
71db76ce |
468 | C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and |
469 | C<builder> to C<_build_${attribute_name}> to allow on-demand generated |
470 | attributes. This feature was my attempt to fix my incompetence when |
471 | originally designing C<lazy_build>, and is also implemented by |
876b1e94 |
472 | L<MooseX::AttributeShortcuts>. There is, however, nothing to stop you |
473 | using C<lazy> and C<builder> yourself with C<rwp> or C<rw> - it's just that |
474 | this isn't generally a good idea so we don't provide a shortcut for it. |
71db76ce |
475 | |
476 | C<rwp> generates a reader like C<ro>, but also sets C<writer> to |
477 | C<_set_${attribute_name}> for attributes that are designed to be written |
478 | from inside of the class, but read-only from outside. |
479 | This feature comes from L<MooseX::AttributeShortcuts>. |
8146585e |
480 | |
6577509a |
481 | C<rw> generates a normal getter/setter by defaulting C<accessor> to the |
482 | name of the attribute. |
483 | |
8146585e |
484 | =item * isa |
485 | |
52e8f144 |
486 | Takes a coderef which is meant to validate the attribute. Unlike L<Moose>, Moo |
8146585e |
487 | does not include a basic type system, so instead of doing C<< isa => 'Num' >>, |
488 | one should do |
489 | |
c9f73a63 |
490 | isa => sub { |
8146585e |
491 | die "$_[0] is not a number!" unless looks_like_number $_[0] |
492 | }, |
493 | |
9a3fc505 |
494 | Note that the return value is ignored, only whether the sub lives or |
495 | dies matters. |
496 | |
8146585e |
497 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
498 | |
c4074652 |
499 | Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion |
500 | subroutine has been supplied, C<isa> checks are not structural to your code |
501 | and can, if desired, be omitted on non-debug builds (although if this results |
502 | in an uncaught bug causing your program to break, the L<Moo> authors guarantee |
503 | nothing except that you get to keep both halves). |
504 | |
71db76ce |
505 | If you want L<MooseX::Types> style named types, look at |
506 | L<MooX::Types::MooseLike>. |
507 | |
508 | To cause your C<isa> entries to be automatically mapped to named |
509 | L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour |
510 | of creating an anonymous type), set: |
511 | |
512 | $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub { |
513 | require MooseX::Types::Something; |
514 | return MooseX::Types::Something::TypeName(); |
515 | }; |
516 | |
517 | Note that this example is purely illustrative; anything that returns a |
518 | L<Moose::Meta::TypeConstraint> object or something similar enough to it to |
519 | make L<Moose> happy is fine. |
520 | |
8146585e |
521 | =item * coerce |
522 | |
523 | Takes a coderef which is meant to coerce the attribute. The basic idea is to |
524 | do something like the following: |
525 | |
c9f73a63 |
526 | coerce => sub { |
8146585e |
527 | $_[0] + 1 unless $_[0] % 2 |
528 | }, |
529 | |
52e8f144 |
530 | Note that L<Moo> will always fire your coercion: this is to permit |
531 | C<isa> entries to be used purely for bug trapping, whereas coercions are |
c4074652 |
532 | always structural to your code. We do, however, apply any supplied C<isa> |
533 | check after the coercion has run to ensure that it returned a valid value. |
8146585e |
534 | |
23a3e34e |
535 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
2e575bcd |
536 | |
e1efec09 |
537 | =item * handles |
538 | |
539 | Takes a string |
540 | |
69673ca7 |
541 | handles => 'RobotRole' |
542 | |
543 | Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which |
544 | becomes the list of methods to handle. |
e1efec09 |
545 | |
546 | Takes a list of methods |
547 | |
548 | handles => [ qw( one two ) ] |
549 | |
550 | Takes a hashref |
551 | |
552 | handles => { |
553 | un => 'one', |
554 | } |
555 | |
cc7ad717 |
556 | =item * C<trigger> |
8146585e |
557 | |
6fe5100d |
558 | Takes a coderef which will get called any time the attribute is set. This |
cc7ad717 |
559 | includes the constructor, but not default or built values. Coderef will be |
560 | invoked against the object with the new value as an argument. |
8146585e |
561 | |
71db76ce |
562 | If you set this to just C<1>, it generates a trigger which calls the |
563 | C<_trigger_${attr_name}> method on C<$self>. This feature comes from |
564 | L<MooseX::AttributeShortcuts>. |
565 | |
2e575bcd |
566 | Note that Moose also passes the old value, if any; this feature is not yet |
567 | supported. |
568 | |
8146585e |
569 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
570 | |
52e8f144 |
571 | =item * C<default> |
8146585e |
572 | |
2e575bcd |
573 | Takes a coderef which will get called with $self as its only argument |
574 | to populate an attribute if no value is supplied to the constructor - or |
575 | if the attribute is lazy, when the attribute is first retrieved if no |
576 | value has yet been provided. |
577 | |
0e43f98f |
578 | If a simple scalar is provided, it will be inlined as a string. Any non-code |
579 | reference (hash, array) will result in an error - for that case instead use |
580 | a code reference that returns the desired value. |
581 | |
2e575bcd |
582 | Note that if your default is fired during new() there is no guarantee that |
583 | other attributes have been populated yet so you should not rely on their |
584 | existence. |
8146585e |
585 | |
586 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
587 | |
52e8f144 |
588 | =item * C<predicate> |
8146585e |
589 | |
2e575bcd |
590 | Takes a method name which will return true if an attribute has a value. |
8146585e |
591 | |
71db76ce |
592 | If you set this to just C<1>, the predicate is automatically named |
593 | C<has_${attr_name}> if your attribute's name does not start with an |
157aa466 |
594 | underscore, or C<_has_${attr_name_without_the_underscore}> if it does. |
71db76ce |
595 | This feature comes from L<MooseX::AttributeShortcuts>. |
8146585e |
596 | |
52e8f144 |
597 | =item * C<builder> |
8146585e |
598 | |
2e575bcd |
599 | Takes a method name which will be called to create the attribute - functions |
600 | exactly like default except that instead of calling |
601 | |
602 | $default->($self); |
603 | |
604 | Moo will call |
605 | |
606 | $self->$builder; |
8146585e |
607 | |
4752c97b |
608 | The following features come from L<MooseX::AttributeShortcuts>: |
609 | |
ba19b6a9 |
610 | If you set this to just C<1>, the builder is automatically named |
4752c97b |
611 | C<_build_${attr_name}>. |
612 | |
613 | If you set this to a coderef or code-convertible object, that variable will be |
614 | installed under C<$class::_build_${attr_name}> and the builder set to the same |
615 | name. |
71db76ce |
616 | |
52e8f144 |
617 | =item * C<clearer> |
8146585e |
618 | |
619 | Takes a method name which will clear the attribute. |
620 | |
71db76ce |
621 | If you set this to just C<1>, the clearer is automatically named |
622 | C<clear_${attr_name}> if your attribute's name does not start with an |
623 | underscore, or <_clear_${attr_name_without_the_underscore}> if it does. |
624 | This feature comes from L<MooseX::AttributeShortcuts>. |
625 | |
52e8f144 |
626 | =item * C<lazy> |
8146585e |
627 | |
628 | B<Boolean>. Set this if you want values for the attribute to be grabbed |
629 | lazily. This is usually a good idea if you have a L</builder> which requires |
630 | another attribute to be set. |
631 | |
52e8f144 |
632 | =item * C<required> |
8146585e |
633 | |
634 | B<Boolean>. Set this if the attribute must be passed on instantiation. |
635 | |
52e8f144 |
636 | =item * C<reader> |
1eba910c |
637 | |
638 | The value of this attribute will be the name of the method to get the value of |
639 | the attribute. If you like Java style methods, you might set this to |
640 | C<get_foo> |
641 | |
52e8f144 |
642 | =item * C<writer> |
1eba910c |
643 | |
644 | The value of this attribute will be the name of the method to set the value of |
645 | the attribute. If you like Java style methods, you might set this to |
52e8f144 |
646 | C<set_foo>. |
1eba910c |
647 | |
52e8f144 |
648 | =item * C<weak_ref> |
8146585e |
649 | |
650 | B<Boolean>. Set this if you want the reference that the attribute contains to |
651 | be weakened; use this when circular references are possible, which will cause |
652 | leaks. |
653 | |
52e8f144 |
654 | =item * C<init_arg> |
8146585e |
655 | |
656 | Takes the name of the key to look for at instantiation time of the object. A |
657 | common use of this is to make an underscored attribute have a non-underscored |
658 | initialization name. C<undef> means that passing the value in on instantiation |
71db76ce |
659 | is ignored. |
8146585e |
660 | |
7887ffd0 |
661 | =item * C<moosify> |
662 | |
663 | Takes either a coderef or array of coderefs which is meant to transform the |
664 | given attributes specifications if necessary when upgrading to a Moose role or |
665 | class. You shouldn't need this by default, but is provided as a means of |
666 | possible extensibility. |
667 | |
8146585e |
668 | =back |
669 | |
670 | =head2 before |
671 | |
672 | before foo => sub { ... }; |
673 | |
674 | See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full |
675 | documentation. |
676 | |
677 | =head2 around |
678 | |
679 | around foo => sub { ... }; |
680 | |
681 | See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full |
682 | documentation. |
683 | |
684 | =head2 after |
685 | |
686 | after foo => sub { ... }; |
687 | |
688 | See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full |
689 | documentation. |
690 | |
8146585e |
691 | =head1 SUB QUOTE AWARE |
692 | |
693 | L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable," |
694 | giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote> |
695 | aware can take advantage of this. |
696 | |
c9f73a63 |
697 | To do this, you can write |
698 | |
699 | use Moo; |
700 | use Sub::Quote; |
701 | |
702 | has foo => ( |
3b4a915a |
703 | is => 'ro', |
704 | isa => quote_sub(q{ die "Not <3" unless $_[0] < 3 }) |
c9f73a63 |
705 | ); |
706 | |
707 | which will be inlined as |
708 | |
709 | do { |
710 | local @_ = ($_[0]->{foo}); |
711 | die "Not <3" unless $_[0] < 3; |
712 | } |
713 | |
714 | or to avoid localizing @_, |
715 | |
716 | has foo => ( |
3b4a915a |
717 | is => 'ro', |
718 | isa => quote_sub(q{ my ($val) = @_; die "Not <3" unless $val < 3 }) |
c9f73a63 |
719 | ); |
720 | |
721 | which will be inlined as |
722 | |
723 | do { |
724 | my ($val) = ($_[0]->{foo}); |
725 | die "Not <3" unless $val < 3; |
726 | } |
727 | |
728 | See L<Sub::Quote> for more information, including how to pass lexical |
52e8f144 |
729 | captures that will also be compiled into the subroutine. |
c9f73a63 |
730 | |
2e575bcd |
731 | =head1 INCOMPATIBILITIES WITH MOOSE |
8146585e |
732 | |
52e8f144 |
733 | There is no built-in type system. C<isa> is verified with a coderef; if you |
8146585e |
734 | need complex types, just make a library of coderefs, or better yet, functions |
5902c1fc |
735 | that return quoted subs. L<MooX::Types::MooseLike> provides a similar API |
736 | to L<MooseX::Types::Moose> so that you can write |
737 | |
738 | has days_to_live => (is => 'ro', isa => Int); |
739 | |
740 | and have it work with both; it is hoped that providing only subrefs as an |
741 | API will encourage the use of other type systems as well, since it's |
742 | probably the weakest part of Moose design-wise. |
8146585e |
743 | |
2e575bcd |
744 | C<initializer> is not supported in core since the author considers it to be a |
0e43f98f |
745 | bad idea and Moose best practices recommend avoiding it. Meanwhile C<trigger> or |
f88623a1 |
746 | C<coerce> are more likely to be able to fulfill your needs. |
8146585e |
747 | |
748 | There is no meta object. If you need this level of complexity you wanted |
2e575bcd |
749 | L<Moose> - Moo succeeds at being small because it explicitly does not |
f9755246 |
750 | provide a metaprotocol. However, if you load L<Moose>, then |
751 | |
752 | Class::MOP::class_of($moo_class_or_role) |
753 | |
754 | will return an appropriate metaclass pre-populated by L<Moo>. |
8146585e |
755 | |
13e41b70 |
756 | No support for C<super>, C<override>, C<inner>, or C<augment> - the author |
757 | considers augment to be a bad idea, and override can be translated: |
758 | |
759 | override foo => sub { |
760 | ... |
761 | super(); |
762 | ... |
763 | }; |
764 | |
765 | around foo => sub { |
766 | my ($orig, $self) = (shift, shift); |
767 | ... |
768 | $self->$orig(@_); |
769 | ... |
770 | }; |
8146585e |
771 | |
f2eac33e |
772 | The C<dump> method is not provided by default. The author suggests loading |
c96a6326 |
773 | L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and |
774 | using C<$obj-E<gt>$::Dwarn()> instead. |
775 | |
0e43f98f |
776 | L</default> only supports coderefs and plain scalars, because passing a hash |
777 | or array reference as a default is almost always incorrect since the value is |
778 | then shared between all objects using that default. |
8146585e |
779 | |
f9755246 |
780 | C<lazy_build> is not supported; you are instead encouraged to use the |
52e8f144 |
781 | C<< is => 'lazy' >> option supported by L<Moo> and L<MooseX::AttributeShortcuts>. |
8146585e |
782 | |
0e43f98f |
783 | C<auto_deref> is not supported since the author considers it a bad idea and |
784 | it has been considered best practice to avoid it for some time. |
8146585e |
785 | |
f9755246 |
786 | C<documentation> will show up in a L<Moose> metaclass created from your class |
c4074652 |
787 | but is otherwise ignored. Then again, L<Moose> ignores it as well, so this |
f9755246 |
788 | is arguably not an incompatibility. |
40f3e3aa |
789 | |
c4074652 |
790 | Since C<coerce> does not require C<isa> to be defined but L<Moose> does |
52e8f144 |
791 | require it, the metaclass inflation for coerce alone is a trifle insane |
c4074652 |
792 | and if you attempt to subtype the result will almost certainly break. |
793 | |
69673ca7 |
794 | Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest |
795 | similar invocation for L<Moose> would be: |
796 | |
797 | use Moose; |
798 | use warnings FATAL => "all"; |
799 | |
800 | Additionally, L<Moo> supports a set of attribute option shortcuts intended to |
801 | reduce common boilerplate. The set of shortcuts is the same as in the L<Moose> |
239d4711 |
802 | module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you: |
69673ca7 |
803 | |
804 | package MyClass; |
805 | use Moo; |
806 | |
807 | The nearest L<Moose> invocation would be: |
808 | |
809 | package MyClass; |
810 | |
811 | use Moose; |
812 | use warnings FATAL => "all"; |
813 | use MooseX::AttributeShortcuts; |
814 | |
5902c1fc |
815 | or, if you're inheriting from a non-Moose class, |
816 | |
817 | package MyClass; |
818 | |
819 | use Moose; |
820 | use MooseX::NonMoose; |
821 | use warnings FATAL => "all"; |
822 | use MooseX::AttributeShortcuts; |
823 | |
824 | Finally, Moose requires you to call |
825 | |
826 | __PACKAGE__->meta->make_immutable; |
827 | |
828 | at the end of your class to get an inlined (i.e. not horribly slow) |
829 | constructor. Moo does it automatically the first time ->new is called |
917f27ca |
830 | on your class. (C<make_immutable> is a no-op in Moo to ease migration.) |
5902c1fc |
831 | |
6ad9aeab |
832 | An extension L<MooX::late> exists to ease translating Moose packages |
833 | to Moo by providing a more Moose-like interface. |
834 | |
660f3db2 |
835 | =head1 SUPPORT |
836 | |
cb21f16e |
837 | Users' IRC: #moose on irc.perl.org |
9836a6ee |
838 | |
cb21f16e |
839 | =for html <a href="http://chat.mibbit.com/#moose@irc.perl.org">(click for instant chatroom login)</a> |
840 | |
841 | Development and contribution IRC: #web-simple on irc.perl.org |
842 | |
843 | =for html <a href="http://chat.mibbit.com/#web-simple@irc.perl.org">(click for instant chatroom login)</a> |
072d158f |
844 | |
845 | Bugtracker: L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Moo> |
846 | |
847 | Git repository: L<git://git.shadowcat.co.uk/gitmo/Moo.git> |
848 | |
849 | Git web access: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo/Moo.git> |
660f3db2 |
850 | |
40f3e3aa |
851 | =head1 AUTHOR |
852 | |
853 | mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk> |
854 | |
855 | =head1 CONTRIBUTORS |
856 | |
5da684a2 |
857 | dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx> |
858 | |
859 | frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com> |
860 | |
861 | hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org> |
862 | |
863 | jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com> |
864 | |
865 | ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org> |
40f3e3aa |
866 | |
11f7a042 |
867 | chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com> |
868 | |
a17be455 |
869 | ajgb - Alex J. G. Burzyński (cpan:AJGB) <ajgb@cpan.org> |
870 | |
7b8177f8 |
871 | doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net> |
872 | |
1fb2de92 |
873 | perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org> |
874 | |
3202e039 |
875 | Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com> |
876 | |
e355471c |
877 | ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org> |
878 | |
1d17c7c1 |
879 | tobyink - Toby Inkster (cpan:TOBYINK) <tobyink@cpan.org> |
880 | |
d092b5ff |
881 | haarg - Graham Knop (cpan:HAARG) <haarg@cpan.org> |
882 | |
80fd66d7 |
883 | mattp - Matt Phillips (cpan:MATTP) <mattp@cpan.org> |
884 | |
40f3e3aa |
885 | =head1 COPYRIGHT |
886 | |
a958e36d |
887 | Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS> |
40f3e3aa |
888 | as listed above. |
889 | |
890 | =head1 LICENSE |
891 | |
892 | This library is free software and may be distributed under the same terms |
072d158f |
893 | as perl itself. See L<http://dev.perl.org/licenses/>. |
40f3e3aa |
894 | |
895 | =cut |