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 | |
e1865995 |
8 | our $VERSION = '1.003001'; |
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 | $maker_class->new; |
140 | } |
141 | } |
142 | |
a16d301e |
143 | sub _constructor_maker_for { |
4ae155a9 |
144 | my ($class, $target, $select_super) = @_; |
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, $con); |
de5c0e53 |
150 | |
4ae155a9 |
151 | if ($select_super && $MAKERS{$select_super}) { |
152 | $moo_constructor = 1; |
153 | $con = $MAKERS{$select_super}{constructor}; |
154 | } else { |
155 | my $t_new = $target->can('new'); |
156 | if ($t_new) { |
157 | if ($t_new == Moo::Object->can('new')) { |
c4570291 |
158 | $moo_constructor = 1; |
4ae155a9 |
159 | } elsif (my $defer_target = (Sub::Defer::defer_info($t_new)||[])->[0]) { |
160 | my ($pkg) = ($defer_target =~ /^(.*)::[^:]+$/); |
161 | if ($MAKERS{$pkg}) { |
162 | $moo_constructor = 1; |
163 | $con = $MAKERS{$pkg}{constructor}; |
164 | } |
c4570291 |
165 | } |
4ae155a9 |
166 | } else { |
167 | $moo_constructor = 1; # no other constructor, make a Moo one |
c4570291 |
168 | } |
4ae155a9 |
169 | }; |
02e9ef74 |
170 | ($con ? ref($con) : 'Method::Generate::Constructor') |
a16d301e |
171 | ->new( |
172 | package => $target, |
02e9ef74 |
173 | accessor_generator => $class->_accessor_maker_for($target), |
53875e2c |
174 | construction_string => ( |
175 | $moo_constructor |
176 | ? ($con ? $con->construction_string : undef) |
e963cc96 |
177 | : ('$class->'.$target.'::SUPER::new($class->can(q[FOREIGNBUILDARGS]) ? $class->FOREIGNBUILDARGS(@_) : @_)') |
e0e12d16 |
178 | ), |
76ab3977 |
179 | subconstructor_handler => ( |
180 | ' if ($Moo::MAKERS{$class}) {'."\n" |
181 | .' '.$class.'->_constructor_maker_for($class,'.perlstring($target).');'."\n" |
182 | .' return $class->new(@_)'.";\n" |
346177ba |
183 | .' } elsif ($INC{"Moose.pm"} and my $meta = Class::MOP::get_metaclass_by_name($class)) {'."\n" |
eea41fb2 |
184 | .' return $meta->new_object($class->BUILDARGS(@_));'."\n" |
76ab3977 |
185 | .' }'."\n" |
e0e12d16 |
186 | ), |
a16d301e |
187 | ) |
188 | ->install_delayed |
de5c0e53 |
189 | ->register_attribute_specs(%{$con?$con->all_attribute_specs:{}}) |
a16d301e |
190 | } |
191 | } |
192 | |
6c74d087 |
193 | 1; |
a17be455 |
194 | =pod |
195 | |
196 | =encoding utf-8 |
8146585e |
197 | |
505f8b7a |
198 | =head1 NAME |
199 | |
c1c6bd6d |
200 | Moo - Minimalist Object Orientation (with Moose compatibility) |
505f8b7a |
201 | |
8146585e |
202 | =head1 SYNOPSIS |
203 | |
204 | package Cat::Food; |
205 | |
206 | use Moo; |
8146585e |
207 | |
208 | sub feed_lion { |
209 | my $self = shift; |
210 | my $amount = shift || 1; |
211 | |
212 | $self->pounds( $self->pounds - $amount ); |
213 | } |
214 | |
215 | has taste => ( |
216 | is => 'ro', |
217 | ); |
218 | |
219 | has brand => ( |
220 | is => 'ro', |
221 | isa => sub { |
222 | die "Only SWEET-TREATZ supported!" unless $_[0] eq 'SWEET-TREATZ' |
223 | }, |
16382e05 |
224 | ); |
8146585e |
225 | |
226 | has pounds => ( |
227 | is => 'rw', |
c9f73a63 |
228 | isa => sub { die "$_[0] is too much cat food!" unless $_[0] < 15 }, |
8146585e |
229 | ); |
230 | |
231 | 1; |
232 | |
52e8f144 |
233 | And elsewhere: |
8146585e |
234 | |
235 | my $full = Cat::Food->new( |
236 | taste => 'DELICIOUS.', |
237 | brand => 'SWEET-TREATZ', |
238 | pounds => 10, |
239 | ); |
240 | |
241 | $full->feed_lion; |
242 | |
243 | say $full->pounds; |
244 | |
245 | =head1 DESCRIPTION |
246 | |
71bd6a81 |
247 | This module is an extremely light-weight subset of L<Moose> optimised for |
52e8f144 |
248 | rapid startup and "pay only for what you use". |
71bd6a81 |
249 | |
8146585e |
250 | It also avoids depending on any XS modules to allow simple deployments. The |
52e8f144 |
251 | name C<Moo> is based on the idea that it provides almost -- but not quite -- two |
8146585e |
252 | thirds of L<Moose>. |
253 | |
52e8f144 |
254 | Unlike L<Mouse> this module does not aim at full compatibility with |
71bd6a81 |
255 | L<Moose>'s surface syntax, preferring instead of provide full interoperability |
5f0ba39b |
256 | via the metaclass inflation capabilities described in L</MOO AND MOOSE>. |
71bd6a81 |
257 | |
258 | For a full list of the minor differences between L<Moose> and L<Moo>'s surface |
21717718 |
259 | syntax, see L</INCOMPATIBILITIES WITH MOOSE>. |
8146585e |
260 | |
5d5bb71d |
261 | =head1 WHY MOO EXISTS |
262 | |
263 | If you want a full object system with a rich Metaprotocol, L<Moose> is |
264 | already wonderful. |
265 | |
71bd6a81 |
266 | However, sometimes you're writing a command line script or a CGI script |
267 | where fast startup is essential, or code designed to be deployed as a single |
268 | file via L<App::FatPacker>, or you're writing a CPAN module and you want it |
269 | to be usable by people with those constraints. |
270 | |
5d5bb71d |
271 | I've tried several times to use L<Mouse> but it's 3x the size of Moo and |
272 | takes longer to load than most of my Moo based CGI scripts take to run. |
273 | |
274 | If you don't want L<Moose>, you don't want "less metaprotocol" like L<Mouse>, |
52e8f144 |
275 | you want "as little as possible" -- which means "no metaprotocol", which is |
5d5bb71d |
276 | what Moo provides. |
277 | |
71bd6a81 |
278 | Better still, if you install and load L<Moose>, we set up metaclasses for your |
279 | L<Moo> classes and L<Moo::Role> roles, so you can use them in L<Moose> code |
280 | without ever noticing that some of your codebase is using L<Moo>. |
5d5bb71d |
281 | |
52e8f144 |
282 | Hence, Moo exists as its name -- Minimal Object Orientation -- with a pledge |
5d5bb71d |
283 | to make it smooth to upgrade to L<Moose> when you need more than minimal |
284 | features. |
285 | |
71bd6a81 |
286 | =head1 MOO AND MOOSE |
1fce5bc9 |
287 | |
288 | If L<Moo> detects L<Moose> being loaded, it will automatically register |
289 | metaclasses for your L<Moo> and L<Moo::Role> packages, so you should be able |
a297a9ab |
290 | to use them in L<Moose> code without anybody ever noticing you aren't using |
1fce5bc9 |
291 | L<Moose> everywhere. |
292 | |
9a3fc505 |
293 | L<Moo> will also create L<Moose type constraints|Moose::Manual::Types> for |
294 | classes and roles, so that C<< isa => 'MyClass' >> and C<< isa => 'MyRole' >> |
295 | work the same as for L<Moose> classes and roles. |
296 | |
a297a9ab |
297 | Extending a L<Moose> class or consuming a L<Moose::Role> will also work. |
1fce5bc9 |
298 | |
a297a9ab |
299 | So will extending a L<Mouse> class or consuming a L<Mouse::Role> - but note |
300 | that we don't provide L<Mouse> metaclasses or metaroles so the other way |
301 | around doesn't work. This feature exists for L<Any::Moose> users porting to |
52e8f144 |
302 | L<Moo>; enabling L<Mouse> users to use L<Moo> classes is not a priority for us. |
c100c04c |
303 | |
660f3db2 |
304 | This means that there is no need for anything like L<Any::Moose> for Moo |
c100c04c |
305 | code - Moo and Moose code should simply interoperate without problem. To |
306 | handle L<Mouse> code, you'll likely need an empty Moo role or class consuming |
307 | or extending the L<Mouse> stuff since it doesn't register true L<Moose> |
71bd6a81 |
308 | metaclasses like L<Moo> does. |
309 | |
310 | If you want types to be upgraded to the L<Moose> types, use |
311 | L<MooX::Types::MooseLike> and install the L<MooseX::Types> library to |
312 | match the L<MooX::Types::MooseLike> library you're using - L<Moo> will |
313 | load the L<MooseX::Types> library and use that type for the newly created |
314 | metaclass. |
660f3db2 |
315 | |
1fce5bc9 |
316 | If you need to disable the metaclass creation, add: |
317 | |
318 | no Moo::sification; |
319 | |
320 | to your code before Moose is loaded, but bear in mind that this switch is |
a297a9ab |
321 | currently global and turns the mechanism off entirely so don't put this |
322 | in library code. |
1fce5bc9 |
323 | |
dcbfe1d9 |
324 | =head1 MOO AND CLASS::XSACCESSOR |
325 | |
326 | If a new enough version of L<Class::XSAccessor> is available, it |
327 | will be used to generate simple accessors, readers, and writers for |
328 | a speed boost. Simple accessors are those without lazy defaults, |
329 | type checks/coercions, or triggers. Readers and writers generated |
330 | by L<Class::XSAccessor> will behave slightly differently: they will |
331 | reject attempts to call them with the incorrect number of parameters. |
332 | |
c687d016 |
333 | =head1 MOO VERSUS ANY::MOOSE |
334 | |
335 | L<Any::Moose> will load L<Mouse> normally, and L<Moose> in a program using |
336 | L<Moose> - which theoretically allows you to get the startup time of L<Mouse> |
337 | without disadvantaging L<Moose> users. |
338 | |
339 | Sadly, this doesn't entirely work, since the selection is load order dependent |
340 | - L<Moo>'s metaclass inflation system explained above in L</MOO AND MOOSE> is |
341 | significantly more reliable. |
342 | |
343 | So if you want to write a CPAN module that loads fast or has only pure perl |
344 | dependencies but is also fully usable by L<Moose> users, you should be using |
345 | L<Moo>. |
346 | |
347 | For a full explanation, see the article |
348 | L<http://shadow.cat/blog/matt-s-trout/moo-versus-any-moose> which explains |
349 | the differing strategies in more detail and provides a direct example of |
350 | where L<Moo> succeeds and L<Any::Moose> fails. |
351 | |
8146585e |
352 | =head1 IMPORTED METHODS |
353 | |
354 | =head2 new |
355 | |
356 | Foo::Bar->new( attr1 => 3 ); |
357 | |
358 | or |
359 | |
360 | Foo::Bar->new({ attr1 => 3 }); |
361 | |
2e575bcd |
362 | =head2 BUILDARGS |
363 | |
f2eac33e |
364 | sub BUILDARGS { |
a17be455 |
365 | my ( $class, @args ) = @_; |
366 | |
367 | unshift @args, "attr1" if @args % 2 == 1; |
368 | |
f2eac33e |
369 | return { @args }; |
a17be455 |
370 | }; |
371 | |
372 | Foo::Bar->new( 3 ); |
373 | |
374 | The default implementation of this method accepts a hash or hash reference of |
375 | named parameters. If it receives a single argument that isn't a hash reference |
376 | it throws an error. |
377 | |
378 | You can override this method in your class to handle other types of options |
379 | passed to the constructor. |
380 | |
381 | This method should always return a hash reference of named options. |
2e575bcd |
382 | |
76a0beff |
383 | =head2 FOREIGNBUILDARGS |
384 | |
385 | If you are inheriting from a non-Moo class, the arguments passed to the parent |
386 | class constructor can be manipulated by defining a C<FOREIGNBUILDARGS> method. |
416bcb6c |
387 | It will receive the same arguments as C<BUILDARGS>, and should return a list |
76a0beff |
388 | of arguments to pass to the parent class constructor. |
389 | |
2d00f3d6 |
390 | =head2 BUILD |
8146585e |
391 | |
2d00f3d6 |
392 | Define a C<BUILD> method on your class and the constructor will automatically |
393 | call the C<BUILD> method from parent down to child after the object has |
394 | been instantiated. Typically this is used for object validation or possibly |
395 | logging. |
8146585e |
396 | |
2d00f3d6 |
397 | =head2 DEMOLISH |
c2cc003f |
398 | |
debb3fcd |
399 | If you have a C<DEMOLISH> method anywhere in your inheritance hierarchy, |
400 | a C<DESTROY> method is created on first object construction which will call |
c2cc003f |
401 | C<< $instance->DEMOLISH($in_global_destruction) >> for each C<DEMOLISH> |
debb3fcd |
402 | method from child upwards to parents. |
403 | |
404 | Note that the C<DESTROY> method is created on first construction of an object |
405 | of your class in order to not add overhead to classes without C<DEMOLISH> |
406 | methods; this may prove slightly surprising if you try and define your own. |
c2cc003f |
407 | |
8146585e |
408 | =head2 does |
409 | |
410 | if ($foo->does('Some::Role1')) { |
411 | ... |
412 | } |
413 | |
414 | Returns true if the object composes in the passed role. |
415 | |
416 | =head1 IMPORTED SUBROUTINES |
417 | |
418 | =head2 extends |
419 | |
420 | extends 'Parent::Class'; |
421 | |
2e575bcd |
422 | Declares base class. Multiple superclasses can be passed for multiple |
423 | inheritance (but please use roles instead). |
424 | |
425 | Calling extends more than once will REPLACE your superclasses, not add to |
426 | them like 'use base' would. |
8146585e |
427 | |
428 | =head2 with |
429 | |
430 | with 'Some::Role1'; |
8146585e |
431 | |
f9755246 |
432 | or |
433 | |
434 | with 'Some::Role1', 'Some::Role2'; |
435 | |
436 | Composes one or more L<Moo::Role> (or L<Role::Tiny>) roles into the current |
437 | class. An error will be raised if these roles have conflicting methods. |
8146585e |
438 | |
439 | =head2 has |
440 | |
441 | has attr => ( |
442 | is => 'ro', |
443 | ); |
444 | |
445 | Declares an attribute for the class. |
446 | |
1c9916fa |
447 | package Foo; |
448 | use Moo; |
449 | has 'attr' => ( |
450 | is => 'ro' |
451 | ); |
d56136b9 |
452 | |
1c9916fa |
453 | package Bar; |
454 | use Moo; |
455 | extends 'Foo'; |
d56136b9 |
456 | has '+attr' => ( |
457 | default => sub { "blah" }, |
458 | ); |
459 | |
460 | Using the C<+> notation, it's possible to override an attribute. |
461 | |
8146585e |
462 | The options for C<has> are as follows: |
463 | |
464 | =over 2 |
465 | |
466 | =item * is |
467 | |
6577509a |
468 | B<required>, may be C<ro>, C<lazy>, C<rwp> or C<rw>. |
71db76ce |
469 | |
470 | C<ro> generates an accessor that dies if you attempt to write to it - i.e. |
471 | a getter only - by defaulting C<reader> to the name of the attribute. |
472 | |
71db76ce |
473 | C<lazy> generates a reader like C<ro>, but also sets C<lazy> to 1 and |
474 | C<builder> to C<_build_${attribute_name}> to allow on-demand generated |
475 | attributes. This feature was my attempt to fix my incompetence when |
476 | originally designing C<lazy_build>, and is also implemented by |
876b1e94 |
477 | L<MooseX::AttributeShortcuts>. There is, however, nothing to stop you |
478 | using C<lazy> and C<builder> yourself with C<rwp> or C<rw> - it's just that |
479 | this isn't generally a good idea so we don't provide a shortcut for it. |
71db76ce |
480 | |
481 | C<rwp> generates a reader like C<ro>, but also sets C<writer> to |
482 | C<_set_${attribute_name}> for attributes that are designed to be written |
483 | from inside of the class, but read-only from outside. |
484 | This feature comes from L<MooseX::AttributeShortcuts>. |
8146585e |
485 | |
6577509a |
486 | C<rw> generates a normal getter/setter by defaulting C<accessor> to the |
487 | name of the attribute. |
488 | |
8146585e |
489 | =item * isa |
490 | |
52e8f144 |
491 | Takes a coderef which is meant to validate the attribute. Unlike L<Moose>, Moo |
8146585e |
492 | does not include a basic type system, so instead of doing C<< isa => 'Num' >>, |
493 | one should do |
494 | |
c9f73a63 |
495 | isa => sub { |
8146585e |
496 | die "$_[0] is not a number!" unless looks_like_number $_[0] |
497 | }, |
498 | |
9a3fc505 |
499 | Note that the return value is ignored, only whether the sub lives or |
500 | dies matters. |
501 | |
8146585e |
502 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
503 | |
c4074652 |
504 | Since L<Moo> does B<not> run the C<isa> check before C<coerce> if a coercion |
505 | subroutine has been supplied, C<isa> checks are not structural to your code |
506 | and can, if desired, be omitted on non-debug builds (although if this results |
507 | in an uncaught bug causing your program to break, the L<Moo> authors guarantee |
508 | nothing except that you get to keep both halves). |
509 | |
71db76ce |
510 | If you want L<MooseX::Types> style named types, look at |
511 | L<MooX::Types::MooseLike>. |
512 | |
513 | To cause your C<isa> entries to be automatically mapped to named |
514 | L<Moose::Meta::TypeConstraint> objects (rather than the default behaviour |
515 | of creating an anonymous type), set: |
516 | |
517 | $Moo::HandleMoose::TYPE_MAP{$isa_coderef} = sub { |
518 | require MooseX::Types::Something; |
519 | return MooseX::Types::Something::TypeName(); |
520 | }; |
521 | |
522 | Note that this example is purely illustrative; anything that returns a |
523 | L<Moose::Meta::TypeConstraint> object or something similar enough to it to |
524 | make L<Moose> happy is fine. |
525 | |
8146585e |
526 | =item * coerce |
527 | |
528 | Takes a coderef which is meant to coerce the attribute. The basic idea is to |
529 | do something like the following: |
530 | |
c9f73a63 |
531 | coerce => sub { |
349ea75b |
532 | $_[0] % 2 ? $_[0] : $_[0] + 1 |
8146585e |
533 | }, |
534 | |
52e8f144 |
535 | Note that L<Moo> will always fire your coercion: this is to permit |
536 | C<isa> entries to be used purely for bug trapping, whereas coercions are |
c4074652 |
537 | always structural to your code. We do, however, apply any supplied C<isa> |
538 | check after the coercion has run to ensure that it returned a valid value. |
8146585e |
539 | |
23a3e34e |
540 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
2e575bcd |
541 | |
e1efec09 |
542 | =item * handles |
543 | |
544 | Takes a string |
545 | |
69673ca7 |
546 | handles => 'RobotRole' |
547 | |
548 | Where C<RobotRole> is a role (L<Moo::Role>) that defines an interface which |
549 | becomes the list of methods to handle. |
e1efec09 |
550 | |
551 | Takes a list of methods |
552 | |
553 | handles => [ qw( one two ) ] |
554 | |
555 | Takes a hashref |
556 | |
557 | handles => { |
558 | un => 'one', |
559 | } |
560 | |
cc7ad717 |
561 | =item * C<trigger> |
8146585e |
562 | |
6fe5100d |
563 | Takes a coderef which will get called any time the attribute is set. This |
cc7ad717 |
564 | includes the constructor, but not default or built values. Coderef will be |
565 | invoked against the object with the new value as an argument. |
8146585e |
566 | |
71db76ce |
567 | If you set this to just C<1>, it generates a trigger which calls the |
568 | C<_trigger_${attr_name}> method on C<$self>. This feature comes from |
569 | L<MooseX::AttributeShortcuts>. |
570 | |
2e575bcd |
571 | Note that Moose also passes the old value, if any; this feature is not yet |
572 | supported. |
573 | |
8146585e |
574 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
575 | |
52e8f144 |
576 | =item * C<default> |
8146585e |
577 | |
2e575bcd |
578 | Takes a coderef which will get called with $self as its only argument |
579 | to populate an attribute if no value is supplied to the constructor - or |
580 | if the attribute is lazy, when the attribute is first retrieved if no |
581 | value has yet been provided. |
582 | |
0e43f98f |
583 | If a simple scalar is provided, it will be inlined as a string. Any non-code |
584 | reference (hash, array) will result in an error - for that case instead use |
585 | a code reference that returns the desired value. |
586 | |
2e575bcd |
587 | Note that if your default is fired during new() there is no guarantee that |
588 | other attributes have been populated yet so you should not rely on their |
589 | existence. |
8146585e |
590 | |
591 | L<Sub::Quote aware|/SUB QUOTE AWARE> |
592 | |
52e8f144 |
593 | =item * C<predicate> |
8146585e |
594 | |
2e575bcd |
595 | Takes a method name which will return true if an attribute has a value. |
8146585e |
596 | |
71db76ce |
597 | If you set this to just C<1>, the predicate is automatically named |
598 | C<has_${attr_name}> if your attribute's name does not start with an |
157aa466 |
599 | underscore, or C<_has_${attr_name_without_the_underscore}> if it does. |
71db76ce |
600 | This feature comes from L<MooseX::AttributeShortcuts>. |
8146585e |
601 | |
52e8f144 |
602 | =item * C<builder> |
8146585e |
603 | |
2e575bcd |
604 | Takes a method name which will be called to create the attribute - functions |
605 | exactly like default except that instead of calling |
606 | |
607 | $default->($self); |
608 | |
609 | Moo will call |
610 | |
611 | $self->$builder; |
8146585e |
612 | |
4752c97b |
613 | The following features come from L<MooseX::AttributeShortcuts>: |
614 | |
ba19b6a9 |
615 | If you set this to just C<1>, the builder is automatically named |
4752c97b |
616 | C<_build_${attr_name}>. |
617 | |
618 | If you set this to a coderef or code-convertible object, that variable will be |
619 | installed under C<$class::_build_${attr_name}> and the builder set to the same |
620 | name. |
71db76ce |
621 | |
52e8f144 |
622 | =item * C<clearer> |
8146585e |
623 | |
624 | Takes a method name which will clear the attribute. |
625 | |
71db76ce |
626 | If you set this to just C<1>, the clearer is automatically named |
627 | C<clear_${attr_name}> if your attribute's name does not start with an |
628 | underscore, or <_clear_${attr_name_without_the_underscore}> if it does. |
629 | This feature comes from L<MooseX::AttributeShortcuts>. |
630 | |
52e8f144 |
631 | =item * C<lazy> |
8146585e |
632 | |
633 | B<Boolean>. Set this if you want values for the attribute to be grabbed |
634 | lazily. This is usually a good idea if you have a L</builder> which requires |
635 | another attribute to be set. |
636 | |
52e8f144 |
637 | =item * C<required> |
8146585e |
638 | |
639 | B<Boolean>. Set this if the attribute must be passed on instantiation. |
640 | |
52e8f144 |
641 | =item * C<reader> |
1eba910c |
642 | |
643 | The value of this attribute will be the name of the method to get the value of |
644 | the attribute. If you like Java style methods, you might set this to |
645 | C<get_foo> |
646 | |
52e8f144 |
647 | =item * C<writer> |
1eba910c |
648 | |
649 | The value of this attribute will be the name of the method to set the value of |
650 | the attribute. If you like Java style methods, you might set this to |
52e8f144 |
651 | C<set_foo>. |
1eba910c |
652 | |
52e8f144 |
653 | =item * C<weak_ref> |
8146585e |
654 | |
655 | B<Boolean>. Set this if you want the reference that the attribute contains to |
656 | be weakened; use this when circular references are possible, which will cause |
657 | leaks. |
658 | |
52e8f144 |
659 | =item * C<init_arg> |
8146585e |
660 | |
661 | Takes the name of the key to look for at instantiation time of the object. A |
662 | common use of this is to make an underscored attribute have a non-underscored |
663 | initialization name. C<undef> means that passing the value in on instantiation |
71db76ce |
664 | is ignored. |
8146585e |
665 | |
7887ffd0 |
666 | =item * C<moosify> |
667 | |
668 | Takes either a coderef or array of coderefs which is meant to transform the |
669 | given attributes specifications if necessary when upgrading to a Moose role or |
670 | class. You shouldn't need this by default, but is provided as a means of |
671 | possible extensibility. |
672 | |
8146585e |
673 | =back |
674 | |
675 | =head2 before |
676 | |
677 | before foo => sub { ... }; |
678 | |
679 | See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full |
680 | documentation. |
681 | |
682 | =head2 around |
683 | |
684 | around foo => sub { ... }; |
685 | |
686 | See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full |
687 | documentation. |
688 | |
689 | =head2 after |
690 | |
691 | after foo => sub { ... }; |
692 | |
693 | See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full |
694 | documentation. |
695 | |
8146585e |
696 | =head1 SUB QUOTE AWARE |
697 | |
698 | L<Sub::Quote/quote_sub> allows us to create coderefs that are "inlineable," |
699 | giving us a handy, XS-free speed boost. Any option that is L<Sub::Quote> |
700 | aware can take advantage of this. |
701 | |
c9f73a63 |
702 | To do this, you can write |
703 | |
704 | use Moo; |
705 | use Sub::Quote; |
706 | |
707 | has foo => ( |
3b4a915a |
708 | is => 'ro', |
709 | isa => quote_sub(q{ die "Not <3" unless $_[0] < 3 }) |
c9f73a63 |
710 | ); |
711 | |
712 | which will be inlined as |
713 | |
714 | do { |
715 | local @_ = ($_[0]->{foo}); |
716 | die "Not <3" unless $_[0] < 3; |
717 | } |
718 | |
719 | or to avoid localizing @_, |
720 | |
721 | has foo => ( |
3b4a915a |
722 | is => 'ro', |
723 | isa => quote_sub(q{ my ($val) = @_; die "Not <3" unless $val < 3 }) |
c9f73a63 |
724 | ); |
725 | |
726 | which will be inlined as |
727 | |
728 | do { |
729 | my ($val) = ($_[0]->{foo}); |
730 | die "Not <3" unless $val < 3; |
731 | } |
732 | |
733 | See L<Sub::Quote> for more information, including how to pass lexical |
52e8f144 |
734 | captures that will also be compiled into the subroutine. |
c9f73a63 |
735 | |
2e575bcd |
736 | =head1 INCOMPATIBILITIES WITH MOOSE |
8146585e |
737 | |
52e8f144 |
738 | There is no built-in type system. C<isa> is verified with a coderef; if you |
8146585e |
739 | need complex types, just make a library of coderefs, or better yet, functions |
5902c1fc |
740 | that return quoted subs. L<MooX::Types::MooseLike> provides a similar API |
741 | to L<MooseX::Types::Moose> so that you can write |
742 | |
743 | has days_to_live => (is => 'ro', isa => Int); |
744 | |
745 | and have it work with both; it is hoped that providing only subrefs as an |
746 | API will encourage the use of other type systems as well, since it's |
747 | probably the weakest part of Moose design-wise. |
8146585e |
748 | |
2e575bcd |
749 | C<initializer> is not supported in core since the author considers it to be a |
0e43f98f |
750 | bad idea and Moose best practices recommend avoiding it. Meanwhile C<trigger> or |
f88623a1 |
751 | C<coerce> are more likely to be able to fulfill your needs. |
8146585e |
752 | |
753 | There is no meta object. If you need this level of complexity you wanted |
2e575bcd |
754 | L<Moose> - Moo succeeds at being small because it explicitly does not |
f9755246 |
755 | provide a metaprotocol. However, if you load L<Moose>, then |
756 | |
757 | Class::MOP::class_of($moo_class_or_role) |
758 | |
759 | will return an appropriate metaclass pre-populated by L<Moo>. |
8146585e |
760 | |
13e41b70 |
761 | No support for C<super>, C<override>, C<inner>, or C<augment> - the author |
762 | considers augment to be a bad idea, and override can be translated: |
763 | |
764 | override foo => sub { |
765 | ... |
766 | super(); |
767 | ... |
768 | }; |
769 | |
770 | around foo => sub { |
771 | my ($orig, $self) = (shift, shift); |
772 | ... |
773 | $self->$orig(@_); |
774 | ... |
775 | }; |
8146585e |
776 | |
f2eac33e |
777 | The C<dump> method is not provided by default. The author suggests loading |
c96a6326 |
778 | L<Devel::Dwarn> into C<main::> (via C<perl -MDevel::Dwarn ...> for example) and |
779 | using C<$obj-E<gt>$::Dwarn()> instead. |
780 | |
0e43f98f |
781 | L</default> only supports coderefs and plain scalars, because passing a hash |
782 | or array reference as a default is almost always incorrect since the value is |
783 | then shared between all objects using that default. |
8146585e |
784 | |
f9755246 |
785 | C<lazy_build> is not supported; you are instead encouraged to use the |
52e8f144 |
786 | C<< is => 'lazy' >> option supported by L<Moo> and L<MooseX::AttributeShortcuts>. |
8146585e |
787 | |
0e43f98f |
788 | C<auto_deref> is not supported since the author considers it a bad idea and |
789 | it has been considered best practice to avoid it for some time. |
8146585e |
790 | |
f9755246 |
791 | C<documentation> will show up in a L<Moose> metaclass created from your class |
c4074652 |
792 | but is otherwise ignored. Then again, L<Moose> ignores it as well, so this |
f9755246 |
793 | is arguably not an incompatibility. |
40f3e3aa |
794 | |
c4074652 |
795 | Since C<coerce> does not require C<isa> to be defined but L<Moose> does |
52e8f144 |
796 | require it, the metaclass inflation for coerce alone is a trifle insane |
c4074652 |
797 | and if you attempt to subtype the result will almost certainly break. |
798 | |
69673ca7 |
799 | Handling of warnings: when you C<use Moo> we enable FATAL warnings. The nearest |
800 | similar invocation for L<Moose> would be: |
801 | |
802 | use Moose; |
803 | use warnings FATAL => "all"; |
804 | |
805 | Additionally, L<Moo> supports a set of attribute option shortcuts intended to |
806 | reduce common boilerplate. The set of shortcuts is the same as in the L<Moose> |
239d4711 |
807 | module L<MooseX::AttributeShortcuts> as of its version 0.009+. So if you: |
69673ca7 |
808 | |
809 | package MyClass; |
810 | use Moo; |
811 | |
812 | The nearest L<Moose> invocation would be: |
813 | |
814 | package MyClass; |
815 | |
816 | use Moose; |
817 | use warnings FATAL => "all"; |
818 | use MooseX::AttributeShortcuts; |
819 | |
5902c1fc |
820 | or, if you're inheriting from a non-Moose class, |
821 | |
822 | package MyClass; |
823 | |
824 | use Moose; |
825 | use MooseX::NonMoose; |
826 | use warnings FATAL => "all"; |
827 | use MooseX::AttributeShortcuts; |
828 | |
829 | Finally, Moose requires you to call |
830 | |
831 | __PACKAGE__->meta->make_immutable; |
832 | |
833 | at the end of your class to get an inlined (i.e. not horribly slow) |
834 | constructor. Moo does it automatically the first time ->new is called |
917f27ca |
835 | on your class. (C<make_immutable> is a no-op in Moo to ease migration.) |
5902c1fc |
836 | |
6ad9aeab |
837 | An extension L<MooX::late> exists to ease translating Moose packages |
838 | to Moo by providing a more Moose-like interface. |
839 | |
660f3db2 |
840 | =head1 SUPPORT |
841 | |
cb21f16e |
842 | Users' IRC: #moose on irc.perl.org |
9836a6ee |
843 | |
cb21f16e |
844 | =for html <a href="http://chat.mibbit.com/#moose@irc.perl.org">(click for instant chatroom login)</a> |
845 | |
846 | Development and contribution IRC: #web-simple on irc.perl.org |
847 | |
848 | =for html <a href="http://chat.mibbit.com/#web-simple@irc.perl.org">(click for instant chatroom login)</a> |
072d158f |
849 | |
850 | Bugtracker: L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Moo> |
851 | |
852 | Git repository: L<git://git.shadowcat.co.uk/gitmo/Moo.git> |
853 | |
854 | Git web access: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo/Moo.git> |
660f3db2 |
855 | |
40f3e3aa |
856 | =head1 AUTHOR |
857 | |
858 | mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk> |
859 | |
860 | =head1 CONTRIBUTORS |
861 | |
5da684a2 |
862 | dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx> |
863 | |
864 | frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com> |
865 | |
866 | hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org> |
867 | |
868 | jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com> |
869 | |
870 | ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org> |
40f3e3aa |
871 | |
11f7a042 |
872 | chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com> |
873 | |
a17be455 |
874 | ajgb - Alex J. G. Burzyński (cpan:AJGB) <ajgb@cpan.org> |
875 | |
7b8177f8 |
876 | doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net> |
877 | |
1fb2de92 |
878 | perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org> |
879 | |
3202e039 |
880 | Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com> |
881 | |
e355471c |
882 | ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org> |
883 | |
1d17c7c1 |
884 | tobyink - Toby Inkster (cpan:TOBYINK) <tobyink@cpan.org> |
885 | |
d092b5ff |
886 | haarg - Graham Knop (cpan:HAARG) <haarg@cpan.org> |
887 | |
80fd66d7 |
888 | mattp - Matt Phillips (cpan:MATTP) <mattp@cpan.org> |
889 | |
40f3e3aa |
890 | =head1 COPYRIGHT |
891 | |
a958e36d |
892 | Copyright (c) 2010-2011 the Moo L</AUTHOR> and L</CONTRIBUTORS> |
40f3e3aa |
893 | as listed above. |
894 | |
895 | =head1 LICENSE |
896 | |
897 | This library is free software and may be distributed under the same terms |
072d158f |
898 | as perl itself. See L<http://dev.perl.org/licenses/>. |
40f3e3aa |
899 | |
900 | =cut |