9 use Scalar::Util 'blessed', 'reftype';
11 use Sub::Name 'subname';
13 use UNIVERSAL::require;
17 use Moose::Meta::Class;
18 use Moose::Meta::TypeConstraint;
19 use Moose::Meta::TypeCoercion;
20 use Moose::Meta::Attribute;
23 use Moose::Util::TypeConstraints;
27 my ( $CALLER, %METAS );
32 return $METAS{$class} if exists $METAS{$class};
34 # make a subtype for each Moose class
37 => where { $_->isa($class) }
38 unless find_type_constraint($class);
41 if ($class->can('meta')) {
42 $meta = $class->meta();
43 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
44 || confess "Whoops, not møøsey enough";
47 $meta = Moose::Meta::Class->initialize($class => (
48 ':attribute_metaclass' => 'Moose::Meta::Attribute'
50 $meta->add_method('meta' => sub {
51 # re-initialize so it inherits properly
52 Moose::Meta::Class->initialize($class => (
53 ':attribute_metaclass' => 'Moose::Meta::Attribute'
58 # make sure they inherit from Moose::Object
59 $meta->superclasses('Moose::Object')
60 unless $meta->superclasses();
62 return $METAS{$class} = $meta;
69 _load_all_classes(@_);
70 $meta->superclasses(@_)
77 _load_all_classes($role);
78 $role->meta->apply($meta);
84 my ($name, %options) = @_;
85 $meta->add_attribute($name, %options)
92 $meta->add_before_method_modifier($_, $code) for @_;
99 $meta->add_after_method_modifier($_, $code) for @_;
106 $meta->add_around_method_modifier($_, $code) for @_;
116 my ($name, $method) = @_;
117 $meta->add_override_method_modifier($name => $method);
127 my ($name, $method) = @_;
128 $meta->add_augment_method_modifier($name => $method);
132 return \&Carp::confess;
135 return \&Scalar::Util::blessed;
139 my $exporter = Sub::Exporter::build_exporter({
140 exports => \%exports,
149 # we should never export to main
150 return if $CALLER eq 'main';
158 sub _load_all_classes {
159 foreach my $super (@_) {
160 # see if this is already
161 # loaded in the symbol table
162 next if _is_class_already_loaded($super);
163 # otherwise require it ...
165 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
169 sub _is_class_already_loaded {
172 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
173 foreach (keys %{"${name}::"}) {
174 next if substr($_, -2, 2) eq '::';
175 return 1 if defined &{"${name}::$_"};
188 Moose - Moose, it's the new Camel
195 has 'x' => (isa => 'Int', is => 'rw');
196 has 'y' => (isa => 'Int', is => 'rw');
209 has 'z' => (isa => 'Int');
211 after 'clear' => sub {
218 This is an early release of this module, it still needs
219 some fine tuning and B<lots> more documentation. I am adopting
220 the I<release early and release often> approach with this module,
221 so keep an eye on your favorite CPAN mirror!
225 Moose is an extension of the Perl 5 object system.
227 =head2 Another object system!?!?
229 Yes, I know there has been an explosion recently of new ways to
230 build object's in Perl 5, most of them based on inside-out objects,
231 and other such things. Moose is different because it is not a new
232 object system for Perl 5, but instead an extension of the existing
235 Moose is built on top of L<Class::MOP>, which is a metaclass system
236 for Perl 5. This means that Moose not only makes building normal
237 Perl 5 objects better, but it also provides the power of metaclass
240 =head2 What does Moose stand for??
242 Moose doesn't stand for one thing in particular, however, if you
243 want, here are a few of my favorites, feel free to contribute
248 =item Make Other Object Systems Envious
250 =item Makes Object Orientation So Easy
252 =item Makes Object Orientation Spiffy- Er (sorry ingy)
254 =item Most Other Object Systems Emasculate
256 =item My Overcraft Overfilled (with) Some Eels
258 =item Moose Often Ovulate Sorta Early
260 =item Many Overloaded Object Systems Exists
262 =item Moose Offers Often Super Extensions
264 =item Meta Object Orientation Syntax Extensions
268 =head1 BUILDING CLASSES WITH MOOSE
270 Moose makes every attempt to provide as much convience during class
271 construction/definition, but still stay out of your way if you want
272 it to. Here are some of the features Moose provides:
274 Unless specified with C<extends>, any class which uses Moose will
275 inherit from L<Moose::Object>.
277 Moose will also manage all attributes (including inherited ones) that
278 are defined with C<has>. And assuming that you call C<new> which is
279 inherited from L<Moose::Object>, then this includes properly initializing
280 all instance slots, setting defaults where approprtiate and performing any
281 type constraint checking or coercion.
283 For more details, see the ever expanding L<Moose::Cookbook>.
285 =head1 EXPORTED FUNCTIONS
287 Moose will export a number of functions into the class's namespace, which
288 can then be used to set up the class. These functions all work directly
289 on the current class.
295 This is a method which provides access to the current class's metaclass.
297 =item B<extends (@superclasses)>
299 This function will set the superclass(es) for the current class.
301 This approach is recommended instead of C<use base>, because C<use base>
302 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
303 replace it. This is important to ensure that classes which do not have
304 superclasses properly inherit from L<Moose::Object>.
306 =item B<with ($role)>
308 This will apply a given C<$role> to the local class. Role support is
309 currently very experimental, see L<Moose::Role> for more details.
311 =item B<has ($name, %options)>
313 This will install an attribute of a given C<$name> into the current class.
314 The list of C<%options> are the same as those provided by both
315 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
316 few convience ones provided by Moose which are listed below:
320 =item I<is =E<gt> 'rw'|'ro'>
322 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
323 only). These will create either a read/write accessor or a read-only
324 accessor respectively, using the same name as the C<$name> of the attribute.
326 If you need more control over how your accessors are named, you can use the
327 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
329 =item I<isa =E<gt> $type_name>
331 The I<isa> option uses Moose's type constraint facilities to set up runtime
332 type checking for this attribute. Moose will perform the checks during class
333 construction, and within any accessors. The C<$type_name> argument must be a
334 string. The string can be either a class name, or a type defined using
335 Moose's type defintion features.
339 =item B<before $name|@names =E<gt> sub { ... }>
341 =item B<after $name|@names =E<gt> sub { ... }>
343 =item B<around $name|@names =E<gt> sub { ... }>
345 This three items are syntactic sugar for the before, after and around method
346 modifier features that L<Class::MOP> provides. More information on these can
347 be found in the L<Class::MOP> documentation for now.
351 The keyword C<super> is a noop when called outside of an C<override> method. In
352 the context of an C<override> method, it will call the next most appropriate
353 superclass method with the same arguments as the original method.
355 =item B<override ($name, &sub)>
357 An C<override> method, is a way of explictly saying "I am overriding this
358 method from my superclass". You can call C<super> within this method, and
359 it will work as expected. The same thing I<can> be accomplished with a normal
360 method call and the C<SUPER::> pseudo-package, it is really your choice.
364 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
365 an C<augment> method. You can think of C<inner> as being the inverse of
366 C<super>, the details of how C<inner> and C<augment> work is best described in
367 the L<Moose::Cookbook>.
369 =item B<augment ($name, &sub)>
371 An C<augment> method, is a way of explictly saying "I am augmenting this
372 method from my superclass". Once again, the details of how C<inner> and
373 C<augment> work is best described in the L<Moose::Cookbook>.
377 This is the C<Carp::confess> function, and exported here beause I use it
378 all the time. This feature may change in the future, so you have been warned.
382 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
383 use it all the time. It is highly recommended that this is used instead of
384 C<ref> anywhere you need to test for an object's class name.
394 It should be noted that C<super> and C<inner> can B<not> be used in the same
395 method. However, they can be combined together with the same class hierarchy,
396 see F<t/014_override_augment_inner_super.t> for an example.
398 The reason that this is so is because C<super> is only valid within a method
399 with the C<override> modifier, and C<inner> will never be valid within an
400 C<override> method. In fact, C<augment> will skip over any C<override> methods
401 when searching for it's appropriate C<inner>.
403 This might seem like a restriction, but I am of the opinion that keeping these
404 two features seperate (but interoperable) actually makes them easy to use since
405 their behavior is then easier to predict. Time will tell if I am right or not.
409 =head1 ACKNOWLEDGEMENTS
413 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
415 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
417 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
418 and it certainly wouldn't have this name ;P
420 =item The basis of the TypeContraints module was Rob Kinyon's idea
421 originally, I just ran with it.
423 =item Thanks to mst & chansen and the whole #moose poose for all the
424 ideas/feature-requests/encouragement
432 =item L<Class::MOP> documentation
434 =item The #moose channel on irc.perl.org
436 =item L<http://forum2.org/moose/>
438 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
440 This paper (suggested by lbr on #moose) was what lead to the implementation
441 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
442 want to understand this feature, I suggest you read this.
448 All complex software has bugs lurking in it, and this module is no
449 exception. If you find a bug please either email me, or add the bug
454 Stevan Little E<lt>stevan@iinteractive.comE<gt>
456 =head1 COPYRIGHT AND LICENSE
458 Copyright 2006 by Infinity Interactive, Inc.
460 L<http://www.iinteractive.com>
462 This library is free software; you can redistribute it and/or modify
463 it under the same terms as Perl itself.