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 => $method);
144 return subname 'Moose::self' => sub {};
148 return subname 'Moose::method' => sub {
149 my ($name, $method) = @_;
150 $class->meta->add_method($name, sub {
153 no warnings 'redefine';
154 local *{$class->meta->name . '::self'} = sub { $self };
161 return \&Carp::confess;
164 return \&Scalar::Util::blessed;
168 my $exporter = Sub::Exporter::build_exporter({
169 exports => \%exports,
181 # we should never export to main
182 return if $CALLER eq 'main';
191 my $class = caller();
192 # loop through the exports ...
193 foreach my $name (keys %exports) {
194 next if $name =~ /inner|super|self/;
197 if (defined &{$class . '::' . $name}) {
198 my $keyword = \&{$class . '::' . $name};
200 # make sure it is from Moose
201 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
203 next if $pkg_name ne 'Moose';
205 # and if it is from Moose then undef the slot
206 delete ${$class . '::'}{$name};
214 sub _load_all_classes {
215 foreach my $super (@_) {
216 # see if this is already
217 # loaded in the symbol table
218 next if _is_class_already_loaded($super);
219 # otherwise require it ...
221 || confess "Could not load module '$super' because : " . $UNIVERSAL::require::ERROR;
225 sub _is_class_already_loaded {
228 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
229 foreach (keys %{"${name}::"}) {
230 next if substr($_, -2, 2) eq '::';
231 return 1 if defined &{"${name}::$_"};
244 Moose - A complete modern object system for Perl 5
253 has 'x' => (is => 'rw', isa => 'Int');
254 has 'y' => (is => 'rw', isa => 'Int');
269 has 'z' => (is => 'rw', isa => 'Int');
271 after 'clear' => sub {
278 Moose is a rapidly maturing module, and is already being used by
279 a number of people. It's test suite is growing larger by the day,
280 and the docs should soon follow.
282 This said, Moose is not yet finished, and should still be considered
283 to be evolving. Much of the outer API is stable, but the internals
284 are still subject to change (although not without serious thought
287 For more details, please refer to the L<FUTURE PLANS> section of
292 Moose is an extension of the Perl 5 object system.
294 =head2 Another object system!?!?
296 Yes, I know there has been an explosion recently of new ways to
297 build object's in Perl 5, most of them based on inside-out objects,
298 and other such things. Moose is different because it is not a new
299 object system for Perl 5, but instead an extension of the existing
302 Moose is built on top of L<Class::MOP>, which is a metaclass system
303 for Perl 5. This means that Moose not only makes building normal
304 Perl 5 objects better, but it also provides the power of metaclass
307 =head2 Can I use this in production? Or is this just an experiment?
309 Moose is I<based> on the prototypes and experiments I did for the Perl 6
310 meta-model, however Moose is B<NOT> an experiment/prototype, it is
311 for B<real>. I will be deploying Moose into production environments later
312 this year, and I have all intentions of using it as my de-facto class
315 =head2 Is Moose just Perl 6 in Perl 5?
317 No. While Moose is very much inspired by Perl 6, it is not. Instead, it
318 is an OO system for Perl 5. I built Moose because I was tired or writing
319 the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
320 instead of switching to Ruby, I wrote Moose :)
322 =head1 BUILDING CLASSES WITH MOOSE
324 Moose makes every attempt to provide as much convience during class
325 construction/definition, but still stay out of your way if you want
326 it to. Here are a few items to note when building classes with Moose.
328 Unless specified with C<extends>, any class which uses Moose will
329 inherit from L<Moose::Object>.
331 Moose will also manage all attributes (including inherited ones) that
332 are defined with C<has>. And assuming that you call C<new> which is
333 inherited from L<Moose::Object>, then this includes properly initializing
334 all instance slots, setting defaults where approprtiate and performing any
335 type constraint checking or coercion.
337 =head1 EXPORTED FUNCTIONS
339 Moose will export a number of functions into the class's namespace, which
340 can then be used to set up the class. These functions all work directly
341 on the current class.
347 This is a method which provides access to the current class's metaclass.
349 =item B<extends (@superclasses)>
351 This function will set the superclass(es) for the current class.
353 This approach is recommended instead of C<use base>, because C<use base>
354 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
355 replace it. This is important to ensure that classes which do not have
356 superclasses properly inherit from L<Moose::Object>.
358 =item B<with (@roles)>
360 This will apply a given set of C<@roles> to the local class. Role support
361 is currently under heavy development, see L<Moose::Role> for more details.
363 =item B<has ($name, %options)>
365 This will install an attribute of a given C<$name> into the current class.
366 The list of C<%options> are the same as those provided by
367 L<Class::MOP::Attribute>, in addition to the list below which are provided
368 by Moose (L<Moose::Meta::Attribute> to be more specific):
372 =item I<is =E<gt> 'rw'|'ro'>
374 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
375 only). These will create either a read/write accessor or a read-only
376 accessor respectively, using the same name as the C<$name> of the attribute.
378 If you need more control over how your accessors are named, you can use the
379 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
381 =item I<isa =E<gt> $type_name>
383 The I<isa> option uses Moose's type constraint facilities to set up runtime
384 type checking for this attribute. Moose will perform the checks during class
385 construction, and within any accessors. The C<$type_name> argument must be a
386 string. The string can be either a class name, or a type defined using
387 Moose's type defintion features.
389 =item I<coerce =E<gt> (1|0)>
391 This will attempt to use coercion with the supplied type constraint to change
392 the value passed into any accessors of constructors. You B<must> have supplied
393 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
394 for an example usage.
396 =item I<does =E<gt> $role_name>
398 This will accept the name of a role which the value stored in this attribute
399 is expected to have consumed.
401 =item I<required =E<gt> (1|0)>
403 This marks the attribute as being required. This means a value must be supplied
404 during class construction, and the attribute can never be set to C<undef> with
407 =item I<weak_ref =E<gt> (1|0)>
409 This will tell the class to strore the value of this attribute as a weakened
410 reference. If an attribute is a weakened reference, it can B<not> also be coerced.
412 =item I<lazy =E<gt> (1|0)>
414 This will tell the class to not create this slot until absolutely nessecary.
415 If an attribute is marked as lazy it B<must> have a default supplied.
417 =item I<auto_deref =E<gt> (1|0)>
419 This tells the accessor whether to automatically de-reference the value returned.
420 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
422 =item I<trigger =E<gt> $code>
424 The trigger option is a CODE reference which will be called after the value of
425 the attribute is set. The CODE ref will be passed the instance itself, the
426 updated value and the attribute meta-object (this is for more advanced fiddling
427 and can typically be ignored in most cases). You can B<not> have a trigger on
428 a read-only attribute.
430 =item I<handles =E<gt> [ @handles ]>
432 There is experimental support for attribute delegation using the C<handles>
433 option. More docs to come later.
437 =item B<before $name|@names =E<gt> sub { ... }>
439 =item B<after $name|@names =E<gt> sub { ... }>
441 =item B<around $name|@names =E<gt> sub { ... }>
443 This three items are syntactic sugar for the before, after and around method
444 modifier features that L<Class::MOP> provides. More information on these can
445 be found in the L<Class::MOP> documentation for now.
449 The keyword C<super> is a noop when called outside of an C<override> method. In
450 the context of an C<override> method, it will call the next most appropriate
451 superclass method with the same arguments as the original method.
453 =item B<override ($name, &sub)>
455 An C<override> method, is a way of explictly saying "I am overriding this
456 method from my superclass". You can call C<super> within this method, and
457 it will work as expected. The same thing I<can> be accomplished with a normal
458 method call and the C<SUPER::> pseudo-package, it is really your choice.
462 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
463 an C<augment> method. You can think of C<inner> as being the inverse of
464 C<super>, the details of how C<inner> and C<augment> work is best described in
465 the L<Moose::Cookbook>.
467 =item B<augment ($name, &sub)>
469 An C<augment> method, is a way of explictly saying "I am augmenting this
470 method from my superclass". Once again, the details of how C<inner> and
471 C<augment> work is best described in the L<Moose::Cookbook>.
475 This is the C<Carp::confess> function, and exported here beause I use it
476 all the time. This feature may change in the future, so you have been warned.
480 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
481 use it all the time. It is highly recommended that this is used instead of
482 C<ref> anywhere you need to test for an object's class name.
486 =head1 UNEXPORTING FUNCTIONS
490 Moose offers a way of removing the keywords it exports though the C<unimport>
491 method. You simply have to say C<no Moose> at the bottom of your code for this
492 to work. Here is an example:
497 has 'first_name' => (is => 'rw', isa => 'Str');
498 has 'last_name' => (is => 'rw', isa => 'Str');
502 $self->first_name . ' ' . $self->last_name
505 no Moose; # keywords are removed from the Person package
509 =head2 What does Moose stand for??
511 Moose doesn't stand for one thing in particular, however, if you
512 want, here are a few of my favorites, feel free to contribute
517 =item Make Other Object Systems Envious
519 =item Makes Object Orientation So Easy
521 =item Makes Object Orientation Spiffy- Er (sorry ingy)
523 =item Most Other Object Systems Emasculate
525 =item Moose Often Ovulate Sorta Early
527 =item Moose Offers Often Super Extensions
529 =item Meta Object Orientation Syntax Extensions
539 It should be noted that C<super> and C<inner> can B<not> be used in the same
540 method. However, they can be combined together with the same class hierarchy,
541 see F<t/014_override_augment_inner_super.t> for an example.
543 The reason that this is so is because C<super> is only valid within a method
544 with the C<override> modifier, and C<inner> will never be valid within an
545 C<override> method. In fact, C<augment> will skip over any C<override> methods
546 when searching for it's appropriate C<inner>.
548 This might seem like a restriction, but I am of the opinion that keeping these
549 two features seperate (but interoperable) actually makes them easy to use since
550 their behavior is then easier to predict. Time will tell if I am right or not.
554 =head1 ACKNOWLEDGEMENTS
558 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
560 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
562 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
563 and it certainly wouldn't have this name ;P
565 =item The basis of the TypeContraints module was Rob Kinyon's idea
566 originally, I just ran with it.
568 =item Thanks to mst & chansen and the whole #moose poose for all the
569 ideas/feature-requests/encouragement
577 =item L<Class::MOP> documentation
579 =item The #moose channel on irc.perl.org
581 =item L<http://forum2.org/moose/>
583 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
585 This paper (suggested by lbr on #moose) was what lead to the implementation
586 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
587 want to understand this feature, I suggest you read this.
593 All complex software has bugs lurking in it, and this module is no
594 exception. If you find a bug please either email me, or add the bug
599 Stevan Little E<lt>stevan@iinteractive.comE<gt>
601 Christian Hansen E<lt>chansen@cpan.orgE<gt>
603 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
605 =head1 COPYRIGHT AND LICENSE
607 Copyright 2006 by Infinity Interactive, Inc.
609 L<http://www.iinteractive.com>
611 This library is free software; you can redistribute it and/or modify
612 it under the same terms as Perl itself.