9 use Scalar::Util 'blessed', 'reftype';
11 use Sub::Name 'subname';
12 use B 'svref_2object';
14 use UNIVERSAL::require;
19 use Moose::Meta::Class;
20 use Moose::Meta::TypeConstraint;
21 use Moose::Meta::TypeCoercion;
22 use Moose::Meta::Attribute;
23 use Moose::Meta::Instance;
26 use Moose::Util::TypeConstraints;
34 # make a subtype for each Moose class
37 => where { $_->isa($class) }
38 unless find_type_constraint($class);
41 if ($class->can('meta')) {
43 # this is the case where the metaclass pragma
44 # was used before the 'use Moose' statement to
45 # override a specific class
46 $meta = $class->meta();
47 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
48 || confess "You already have a &meta function, but it does not return a Moose::Meta::Class";
52 # this is broken currently, we actually need
53 # to allow the possiblity of an inherited
54 # meta, which will not be visible until the
55 # user 'extends' first. This needs to have
56 # more intelligence to it
57 $meta = Moose::Meta::Class->initialize($class);
58 $meta->add_method('meta' => sub {
59 # re-initialize so it inherits properly
60 Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]);
64 # make sure they inherit from Moose::Object
65 $meta->superclasses('Moose::Object')
66 unless $meta->superclasses();
72 return subname 'Moose::extends' => sub (@) {
73 confess "Must derive at least one class" unless @_;
74 _load_all_classes(@_);
75 # this checks the metaclass to make sure
76 # it is correct, sometimes it can get out
77 # of sync when the classes are being built
78 my $meta = $class->meta->_fix_metaclass_incompatability(@_);
79 $meta->superclasses(@_);
84 return subname 'Moose::with' => sub (@) {
86 confess "Must specify at least one role" unless @roles;
87 _load_all_classes(@roles);
88 $class->meta->_apply_all_roles(@roles);
93 return subname 'Moose::has' => sub ($;%) {
94 my ($name, %options) = @_;
95 $class->meta->_process_attribute($name, %options);
100 return subname 'Moose::before' => sub (@&) {
102 my $meta = $class->meta;
103 $meta->add_before_method_modifier($_, $code) for @_;
108 return subname 'Moose::after' => sub (@&) {
110 my $meta = $class->meta;
111 $meta->add_after_method_modifier($_, $code) for @_;
116 return subname 'Moose::around' => sub (@&) {
118 my $meta = $class->meta;
119 $meta->add_around_method_modifier($_, $code) for @_;
123 return subname 'Moose::super' => sub {};
127 return subname 'Moose::override' => sub ($&) {
128 my ($name, $method) = @_;
129 $class->meta->add_override_method_modifier($name => $method);
133 return subname 'Moose::inner' => sub {};
137 return subname 'Moose::augment' => sub (@&) {
138 my ($name, $method) = @_;
139 $class->meta->add_augment_method_modifier($name => $method);
143 return \&Carp::confess;
146 return \&Scalar::Util::blessed;
149 return subname 'Moose::default' => sub (&) {
151 return ('default' => $block);
156 my $exporter = Sub::Exporter::build_exporter({
157 exports => \%exports,
169 # we should never export to main
170 return if $CALLER eq 'main';
179 my $class = caller();
180 # loop through the exports ...
181 foreach my $name (keys %exports) {
184 if (defined &{$class . '::' . $name}) {
185 my $keyword = \&{$class . '::' . $name};
187 # make sure it is from Moose
188 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
190 next if $pkg_name ne 'Moose';
192 # and if it is from Moose then undef the slot
193 delete ${$class . '::'}{$name};
201 sub _load_all_classes {
202 foreach my $super (@_) {
203 # see if this is already
204 # loaded in the symbol table
205 next if _is_class_already_loaded($super);
206 # otherwise require it ...
208 || confess "Could not load module '$super' because : " . $UNIVERSAL::require::ERROR;
212 sub _is_class_already_loaded {
215 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
216 foreach (keys %{"${name}::"}) {
217 next if substr($_, -2, 2) eq '::';
218 return 1 if defined &{"${name}::$_"};
231 Moose - A complete modern object system for Perl 5
240 has 'x' => (is => 'rw', isa => 'Int');
241 has 'y' => (is => 'rw', isa => 'Int');
256 has 'z' => (is => 'rw', isa => 'Int');
258 after 'clear' => sub {
265 Moose is a rapidly maturing module, and is already being used by
266 a number of people. It's test suite is growing larger by the day,
267 and the docs should soon follow.
269 This said, Moose is not yet finished, and should still be considered
270 to be evolving. Much of the outer API is stable, but the internals
271 are still subject to change (although not without serious thought
274 For more details, please refer to the L<FUTURE PLANS> section of
279 Moose is an extension of the Perl 5 object system.
281 =head2 Another object system!?!?
283 Yes, I know there has been an explosion recently of new ways to
284 build object's in Perl 5, most of them based on inside-out objects,
285 and other such things. Moose is different because it is not a new
286 object system for Perl 5, but instead an extension of the existing
289 Moose is built on top of L<Class::MOP>, which is a metaclass system
290 for Perl 5. This means that Moose not only makes building normal
291 Perl 5 objects better, but it also provides the power of metaclass
294 =head2 Can I use this in production? Or is this just an experiment?
296 Moose is I<based> on the prototypes and experiments I did for the Perl 6
297 meta-model, however Moose is B<NOT> an experiment/prototype, it is
298 for B<real>. I will be deploying Moose into production environments later
299 this year, and I have all intentions of using it as my de-facto class
302 =head2 Is Moose just Perl 6 in Perl 5?
304 No. While Moose is very much inspired by Perl 6, it is not. Instead, it
305 is an OO system for Perl 5. I built Moose because I was tired or writing
306 the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
307 instead of switching to Ruby, I wrote Moose :)
309 =head1 BUILDING CLASSES WITH MOOSE
311 Moose makes every attempt to provide as much convience during class
312 construction/definition, but still stay out of your way if you want
313 it to. Here are a few items to note when building classes with Moose.
315 Unless specified with C<extends>, any class which uses Moose will
316 inherit from L<Moose::Object>.
318 Moose will also manage all attributes (including inherited ones) that
319 are defined with C<has>. And assuming that you call C<new> which is
320 inherited from L<Moose::Object>, then this includes properly initializing
321 all instance slots, setting defaults where approprtiate and performing any
322 type constraint checking or coercion.
324 =head1 EXPORTED FUNCTIONS
326 Moose will export a number of functions into the class's namespace, which
327 can then be used to set up the class. These functions all work directly
328 on the current class.
334 This is a method which provides access to the current class's metaclass.
336 =item B<extends (@superclasses)>
338 This function will set the superclass(es) for the current class.
340 This approach is recommended instead of C<use base>, because C<use base>
341 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
342 replace it. This is important to ensure that classes which do not have
343 superclasses properly inherit from L<Moose::Object>.
345 =item B<with (@roles)>
347 This will apply a given set of C<@roles> to the local class. Role support
348 is currently under heavy development, see L<Moose::Role> for more details.
350 =item B<has ($name, %options)>
352 This will install an attribute of a given C<$name> into the current class.
353 The list of C<%options> are the same as those provided by
354 L<Class::MOP::Attribute>, in addition to the list below which are provided
355 by Moose (L<Moose::Meta::Attribute> to be more specific):
359 =item I<is =E<gt> 'rw'|'ro'>
361 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
362 only). These will create either a read/write accessor or a read-only
363 accessor respectively, using the same name as the C<$name> of the attribute.
365 If you need more control over how your accessors are named, you can use the
366 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
368 =item I<isa =E<gt> $type_name>
370 The I<isa> option uses Moose's type constraint facilities to set up runtime
371 type checking for this attribute. Moose will perform the checks during class
372 construction, and within any accessors. The C<$type_name> argument must be a
373 string. The string can be either a class name, or a type defined using
374 Moose's type defintion features.
376 =item I<coerce =E<gt> (1|0)>
378 This will attempt to use coercion with the supplied type constraint to change
379 the value passed into any accessors of constructors. You B<must> have supplied
380 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
381 for an example usage.
383 =item I<does =E<gt> $role_name>
385 This will accept the name of a role which the value stored in this attribute
386 is expected to have consumed.
388 =item I<required =E<gt> (1|0)>
390 This marks the attribute as being required. This means a value must be supplied
391 during class construction, and the attribute can never be set to C<undef> with
394 =item I<weak_ref =E<gt> (1|0)>
396 This will tell the class to strore the value of this attribute as a weakened
397 reference. If an attribute is a weakened reference, it can B<not> also be coerced.
399 =item I<lazy =E<gt> (1|0)>
401 This will tell the class to not create this slot until absolutely nessecary.
402 If an attribute is marked as lazy it B<must> have a default supplied.
404 =item I<auto_deref =E<gt> (1|0)>
406 This tells the accessor whether to automatically de-reference the value returned.
407 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
409 =item I<trigger =E<gt> $code>
411 The trigger option is a CODE reference which will be called after the value of
412 the attribute is set. The CODE ref will be passed the instance itself, the
413 updated value and the attribute meta-object (this is for more advanced fiddling
414 and can typically be ignored in most cases). You can B<not> have a trigger on
415 a read-only attribute.
417 =item I<handles =E<gt> [ @handles ]>
419 There is experimental support for attribute delegation using the C<handles>
420 option. More docs to come later.
424 =item B<before $name|@names =E<gt> sub { ... }>
426 =item B<after $name|@names =E<gt> sub { ... }>
428 =item B<around $name|@names =E<gt> sub { ... }>
430 This three items are syntactic sugar for the before, after and around method
431 modifier features that L<Class::MOP> provides. More information on these can
432 be found in the L<Class::MOP> documentation for now.
436 The keyword C<super> is a noop when called outside of an C<override> method. In
437 the context of an C<override> method, it will call the next most appropriate
438 superclass method with the same arguments as the original method.
440 =item B<override ($name, &sub)>
442 An C<override> method, is a way of explictly saying "I am overriding this
443 method from my superclass". You can call C<super> within this method, and
444 it will work as expected. The same thing I<can> be accomplished with a normal
445 method call and the C<SUPER::> pseudo-package, it is really your choice.
449 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
450 an C<augment> method. You can think of C<inner> as being the inverse of
451 C<super>, the details of how C<inner> and C<augment> work is best described in
452 the L<Moose::Cookbook>.
454 =item B<augment ($name, &sub)>
456 An C<augment> method, is a way of explictly saying "I am augmenting this
457 method from my superclass". Once again, the details of how C<inner> and
458 C<augment> work is best described in the L<Moose::Cookbook>.
462 This is the C<Carp::confess> function, and exported here beause I use it
463 all the time. This feature may change in the future, so you have been warned.
467 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
468 use it all the time. It is highly recommended that this is used instead of
469 C<ref> anywhere you need to test for an object's class name.
473 =head1 UNEXPORTING FUNCTIONS
477 Moose offers a way of removing the keywords it exports though the C<unimport>
478 method. You simply have to say C<no Moose> at the bottom of your code for this
479 to work. Here is an example:
484 has 'first_name' => (is => 'rw', isa => 'Str');
485 has 'last_name' => (is => 'rw', isa => 'Str');
489 $self->first_name . ' ' . $self->last_name
492 no Moose; # keywords are removed from the Person package
496 We have developed a roadmap for the next several releases of Moose.
497 Development is currently moving at a rapid pace, so this roughly
498 represents the next few weeks of Moose.
504 This is the current release, it addresses some inconsistencies with
505 Role composition and method modifiers. As an intermediate step, it
506 removed method modifiers from Roles entirely, and roles can only
507 compose methods and attributes.
511 With this release will be adding a new keyword which will allow a
512 finer grained form of reuse than roles. This keyword will form the
513 basis of the features of the next few releases.
517 With this release we will introduce a deferred version of method
518 modifiers and a package/class-like container to hold them. In
519 conjunction with the new keyword from 0.13, this will bring back
520 the ability to compose groups of method modifiers which was
525 With this release we will attempt to return the ability for Roles
526 to compose method modifiers, by using the features introduced in
529 It is our intention that this release will bring Roles to a
534 The focus of these releases will be to bring the optimization
535 capabilities of class immutability which we introduced in
536 Class::MOP 0.30. I will get into the details of this as we
543 =head2 What does Moose stand for??
545 Moose doesn't stand for one thing in particular, however, if you
546 want, here are a few of my favorites, feel free to contribute
551 =item Make Other Object Systems Envious
553 =item Makes Object Orientation So Easy
555 =item Makes Object Orientation Spiffy- Er (sorry ingy)
557 =item Most Other Object Systems Emasculate
559 =item Moose Often Ovulate Sorta Early
561 =item Moose Offers Often Super Extensions
563 =item Meta Object Orientation Syntax Extensions
573 It should be noted that C<super> and C<inner> can B<not> be used in the same
574 method. However, they can be combined together with the same class hierarchy,
575 see F<t/014_override_augment_inner_super.t> for an example.
577 The reason that this is so is because C<super> is only valid within a method
578 with the C<override> modifier, and C<inner> will never be valid within an
579 C<override> method. In fact, C<augment> will skip over any C<override> methods
580 when searching for it's appropriate C<inner>.
582 This might seem like a restriction, but I am of the opinion that keeping these
583 two features seperate (but interoperable) actually makes them easy to use since
584 their behavior is then easier to predict. Time will tell if I am right or not.
588 =head1 ACKNOWLEDGEMENTS
592 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
594 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
596 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
597 and it certainly wouldn't have this name ;P
599 =item The basis of the TypeContraints module was Rob Kinyon's idea
600 originally, I just ran with it.
602 =item Thanks to mst & chansen and the whole #moose poose for all the
603 ideas/feature-requests/encouragement
611 =item L<Class::MOP> documentation
613 =item The #moose channel on irc.perl.org
615 =item L<http://forum2.org/moose/>
617 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
619 This paper (suggested by lbr on #moose) was what lead to the implementation
620 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
621 want to understand this feature, I suggest you read this.
627 All complex software has bugs lurking in it, and this module is no
628 exception. If you find a bug please either email me, or add the bug
633 Stevan Little E<lt>stevan@iinteractive.comE<gt>
635 Christian Hansen E<lt>chansen@cpan.orgE<gt>
637 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
639 =head1 COPYRIGHT AND LICENSE
641 Copyright 2006 by Infinity Interactive, Inc.
643 L<http://www.iinteractive.com>
645 This library is free software; you can redistribute it and/or modify
646 it under the same terms as Perl itself.