7 our $VERSION = '0.09_03';
9 use Scalar::Util 'blessed', 'reftype';
11 use Sub::Name 'subname';
13 use UNIVERSAL::require;
18 use Moose::Meta::Class;
19 use Moose::Meta::TypeConstraint;
20 use Moose::Meta::TypeCoercion;
21 use Moose::Meta::Attribute;
22 use Moose::Meta::Instance;
25 use Moose::Util::TypeConstraints;
33 # make a subtype for each Moose class
36 => where { $_->isa($class) }
37 unless find_type_constraint($class);
40 if ($class->can('meta')) {
42 # this is the case where the metaclass pragma
43 # was used before the 'use Moose' statement to
44 # override a specific class
45 $meta = $class->meta();
46 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
47 || confess "Whoops, not møøsey enough";
51 # this is broken currently, we actually need
52 # to allow the possiblity of an inherited
53 # meta, which will not be visible until the
54 # user 'extends' first. This needs to have
55 # more intelligence to it
56 $meta = Moose::Meta::Class->initialize($class);
57 $meta->add_method('meta' => sub {
58 # re-initialize so it inherits properly
59 Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]);
63 # make sure they inherit from Moose::Object
64 $meta->superclasses('Moose::Object')
65 unless $meta->superclasses();
71 return subname 'Moose::extends' => sub (@) {
72 confess "Must derive at least one class" unless @_;
73 _load_all_classes(@_);
74 # this checks the metaclass to make sure
75 # it is correct, sometimes it can get out
76 # of sync when the classes are being built
77 my $meta = $class->meta->_fix_metaclass_incompatability(@_);
78 $meta->superclasses(@_);
83 return subname 'Moose::with' => sub (@) {
85 confess "Must specify at least one role" unless @roles;
86 _load_all_classes(@roles);
87 $class->meta->_apply_all_roles(@roles);
92 return subname 'Moose::has' => sub ($;%) {
93 my ($name, %options) = @_;
94 $class->meta->_process_attribute($name, %options);
99 return subname 'Moose::before' => sub (@&) {
101 my $meta = $class->meta;
102 $meta->add_before_method_modifier($_, $code) for @_;
107 return subname 'Moose::after' => sub (@&) {
109 my $meta = $class->meta;
110 $meta->add_after_method_modifier($_, $code) for @_;
115 return subname 'Moose::around' => sub (@&) {
117 my $meta = $class->meta;
118 $meta->add_around_method_modifier($_, $code) for @_;
122 return subname 'Moose::super' => sub {};
126 return subname 'Moose::override' => sub ($&) {
127 my ($name, $method) = @_;
128 $class->meta->add_override_method_modifier($name => $method);
132 return subname 'Moose::inner' => sub {};
136 return subname 'Moose::augment' => sub (@&) {
137 my ($name, $method) = @_;
138 $class->meta->add_augment_method_modifier($name => $method);
142 return \&Carp::confess;
145 return \&Scalar::Util::blessed;
149 my $exporter = Sub::Exporter::build_exporter({
150 exports => \%exports,
162 # we should never export to main
163 return if $CALLER eq 'main';
173 sub _load_all_classes {
174 foreach my $super (@_) {
175 # see if this is already
176 # loaded in the symbol table
177 next if _is_class_already_loaded($super);
178 # otherwise require it ...
180 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
184 sub _is_class_already_loaded {
187 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
188 foreach (keys %{"${name}::"}) {
189 next if substr($_, -2, 2) eq '::';
190 return 1 if defined &{"${name}::$_"};
203 Moose - Moose, it's the new Camel
212 has 'x' => (is => 'rw', isa => 'Int');
213 has 'y' => (is => 'rw', isa => 'Int');
228 has 'z' => (is => 'rw', isa => 'Int');
230 after 'clear' => sub {
237 Moose is a rapidly maturing module, and is already being used by
238 a number of people. It's test suite is growing larger by the day,
239 and the docs should soon follow.
241 This said, Moose is not yet finished, and should still be considered
242 to be evolving. Much of the outer API is stable, but the internals
243 are still subject to change (although not without serious thought
246 For more details, please refer to the L<FUTURE PLANS> section of
251 Moose is an extension of the Perl 5 object system.
253 =head2 Another object system!?!?
255 Yes, I know there has been an explosion recently of new ways to
256 build object's in Perl 5, most of them based on inside-out objects,
257 and other such things. Moose is different because it is not a new
258 object system for Perl 5, but instead an extension of the existing
261 Moose is built on top of L<Class::MOP>, which is a metaclass system
262 for Perl 5. This means that Moose not only makes building normal
263 Perl 5 objects better, but it also provides the power of metaclass
266 =head2 Can I use this in production? Or is this just an experiment?
268 Moose is I<based> on the prototypes and experiments I did for the Perl 6
269 meta-model, however Moose is B<NOT> an experiment/prototype, it is
270 for B<real>. I will be deploying Moose into production environments later
271 this year, and I have all intentions of using it as my de-facto class
274 =head2 Is Moose just Perl 6 in Perl 5?
276 No. While Moose is very much inspired by Perl 6, it is not. Instead, it
277 is an OO system for Perl 5. I built Moose because I was tired or writing
278 the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
279 instead of switching to Ruby, I wrote Moose :)
281 =head1 BUILDING CLASSES WITH MOOSE
283 Moose makes every attempt to provide as much convience during class
284 construction/definition, but still stay out of your way if you want
285 it to. Here are a few items to note when building classes with Moose.
287 Unless specified with C<extends>, any class which uses Moose will
288 inherit from L<Moose::Object>.
290 Moose will also manage all attributes (including inherited ones) that
291 are defined with C<has>. And assuming that you call C<new> which is
292 inherited from L<Moose::Object>, then this includes properly initializing
293 all instance slots, setting defaults where approprtiate and performing any
294 type constraint checking or coercion.
296 =head1 EXPORTED FUNCTIONS
298 Moose will export a number of functions into the class's namespace, which
299 can then be used to set up the class. These functions all work directly
300 on the current class.
306 This is a method which provides access to the current class's metaclass.
308 =item B<extends (@superclasses)>
310 This function will set the superclass(es) for the current class.
312 This approach is recommended instead of C<use base>, because C<use base>
313 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
314 replace it. This is important to ensure that classes which do not have
315 superclasses properly inherit from L<Moose::Object>.
317 =item B<with (@roles)>
319 This will apply a given set of C<@roles> to the local class. Role support
320 is currently under heavy development, see L<Moose::Role> for more details.
322 =item B<has ($name, %options)>
324 This will install an attribute of a given C<$name> into the current class.
325 The list of C<%options> are the same as those provided by
326 L<Class::MOP::Attribute>, in addition to the list below which are provided
327 by Moose (L<Moose::Meta::Attribute> to be more specific):
331 =item I<is =E<gt> 'rw'|'ro'>
333 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
334 only). These will create either a read/write accessor or a read-only
335 accessor respectively, using the same name as the C<$name> of the attribute.
337 If you need more control over how your accessors are named, you can use the
338 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
340 =item I<isa =E<gt> $type_name>
342 The I<isa> option uses Moose's type constraint facilities to set up runtime
343 type checking for this attribute. Moose will perform the checks during class
344 construction, and within any accessors. The C<$type_name> argument must be a
345 string. The string can be either a class name, or a type defined using
346 Moose's type defintion features.
348 =item I<coerce =E<gt> (1|0)>
350 This will attempt to use coercion with the supplied type constraint to change
351 the value passed into any accessors of constructors. You B<must> have supplied
352 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
353 for an example usage.
355 =item I<does =E<gt> $role_name>
357 This will accept the name of a role which the value stored in this attribute
358 is expected to have consumed.
360 =item I<required =E<gt> (1|0)>
362 This marks the attribute as being required. This means a value must be supplied
363 during class construction, and the attribute can never be set to C<undef> with
366 =item I<weak_ref =E<gt> (1|0)>
368 This will tell the class to strore the value of this attribute as a weakened
369 reference. If an attribute is a weakened reference, it can B<not> also be coerced.
371 =item I<lazy =E<gt> (1|0)>
373 This will tell the class to not create this slot until absolutely nessecary.
374 If an attribute is marked as lazy it B<must> have a default supplied.
376 =item I<auto_deref =E<gt> (1|0)>
378 This tells the accessor whether to automatically de-reference the value returned.
379 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
381 =item I<trigger =E<gt> $code>
383 The trigger option is a CODE reference which will be called after the value of
384 the attribute is set. The CODE ref will be passed the instance itself, the
385 updated value and the attribute meta-object (this is for more advanced fiddling
386 and can typically be ignored in most cases). You can B<not> have a trigger on
387 a read-only attribute.
389 =item I<handles =E<gt> [ @handles ]>
391 There is experimental support for attribute delegation using the C<handles>
392 option. More docs to come later.
396 =item B<before $name|@names =E<gt> sub { ... }>
398 =item B<after $name|@names =E<gt> sub { ... }>
400 =item B<around $name|@names =E<gt> sub { ... }>
402 This three items are syntactic sugar for the before, after and around method
403 modifier features that L<Class::MOP> provides. More information on these can
404 be found in the L<Class::MOP> documentation for now.
408 The keyword C<super> is a noop when called outside of an C<override> method. In
409 the context of an C<override> method, it will call the next most appropriate
410 superclass method with the same arguments as the original method.
412 =item B<override ($name, &sub)>
414 An C<override> method, is a way of explictly saying "I am overriding this
415 method from my superclass". You can call C<super> within this method, and
416 it will work as expected. The same thing I<can> be accomplished with a normal
417 method call and the C<SUPER::> pseudo-package, it is really your choice.
421 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
422 an C<augment> method. You can think of C<inner> as being the inverse of
423 C<super>, the details of how C<inner> and C<augment> work is best described in
424 the L<Moose::Cookbook>.
426 =item B<augment ($name, &sub)>
428 An C<augment> method, is a way of explictly saying "I am augmenting this
429 method from my superclass". Once again, the details of how C<inner> and
430 C<augment> work is best described in the L<Moose::Cookbook>.
434 This is the C<Carp::confess> function, and exported here beause I use it
435 all the time. This feature may change in the future, so you have been warned.
439 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
440 use it all the time. It is highly recommended that this is used instead of
441 C<ref> anywhere you need to test for an object's class name.
447 Here is just a sampling of the plans we have in store for Moose:
453 Compiling Moose classes/roles into C<.pmc> files for faster loading and execution.
457 Supporting sealed and finalized classes in Moose. This will allow greater control
458 of the extensions of frameworks and such.
464 =head2 What does Moose stand for??
466 Moose doesn't stand for one thing in particular, however, if you
467 want, here are a few of my favorites, feel free to contribute
472 =item Make Other Object Systems Envious
474 =item Makes Object Orientation So Easy
476 =item Makes Object Orientation Spiffy- Er (sorry ingy)
478 =item Most Other Object Systems Emasculate
480 =item Moose Often Ovulate Sorta Early
482 =item Moose Offers Often Super Extensions
484 =item Meta Object Orientation Syntax Extensions
494 It should be noted that C<super> and C<inner> can B<not> be used in the same
495 method. However, they can be combined together with the same class hierarchy,
496 see F<t/014_override_augment_inner_super.t> for an example.
498 The reason that this is so is because C<super> is only valid within a method
499 with the C<override> modifier, and C<inner> will never be valid within an
500 C<override> method. In fact, C<augment> will skip over any C<override> methods
501 when searching for it's appropriate C<inner>.
503 This might seem like a restriction, but I am of the opinion that keeping these
504 two features seperate (but interoperable) actually makes them easy to use since
505 their behavior is then easier to predict. Time will tell if I am right or not.
509 =head1 ACKNOWLEDGEMENTS
513 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
515 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
517 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
518 and it certainly wouldn't have this name ;P
520 =item The basis of the TypeContraints module was Rob Kinyon's idea
521 originally, I just ran with it.
523 =item Thanks to mst & chansen and the whole #moose poose for all the
524 ideas/feature-requests/encouragement
532 =item L<Class::MOP> documentation
534 =item The #moose channel on irc.perl.org
536 =item L<http://forum2.org/moose/>
538 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
540 This paper (suggested by lbr on #moose) was what lead to the implementation
541 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
542 want to understand this feature, I suggest you read this.
548 All complex software has bugs lurking in it, and this module is no
549 exception. If you find a bug please either email me, or add the bug
554 Stevan Little E<lt>stevan@iinteractive.comE<gt>
556 Christian Hansen E<lt>chansen@cpan.orgE<gt>
558 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
560 =head1 COPYRIGHT AND LICENSE
562 Copyright 2006 by Infinity Interactive, Inc.
564 L<http://www.iinteractive.com>
566 This library is free software; you can redistribute it and/or modify
567 it under the same terms as Perl itself.