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 foreach my $name (keys %exports) {
140 $exports{$name} = subname "Moose::${name}" => $exports{$name};
143 my $exporter = Sub::Exporter::build_exporter({
144 exports => \%exports,
153 # we should never export to main
154 return if $CALLER eq 'main';
162 sub _load_all_classes {
163 foreach my $super (@_) {
164 # see if this is already
165 # loaded in the symbol table
166 next if _is_class_already_loaded($super);
167 # otherwise require it ...
169 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
173 sub _is_class_already_loaded {
176 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
177 foreach (keys %{"${name}::"}) {
178 next if substr($_, -2, 2) eq '::';
179 return 1 if defined &{"${name}::$_"};
192 Moose - Moose, it's the new Camel
199 has 'x' => (isa => 'Int', is => 'rw');
200 has 'y' => (isa => 'Int', is => 'rw');
213 has 'z' => (isa => 'Int');
215 after 'clear' => sub {
222 This is an early release of this module, it still needs
223 some fine tuning and B<lots> more documentation. I am adopting
224 the I<release early and release often> approach with this module,
225 so keep an eye on your favorite CPAN mirror!
229 Moose is an extension of the Perl 5 object system.
231 =head2 Another object system!?!?
233 Yes, I know there has been an explosion recently of new ways to
234 build object's in Perl 5, most of them based on inside-out objects,
235 and other such things. Moose is different because it is not a new
236 object system for Perl 5, but instead an extension of the existing
239 Moose is built on top of L<Class::MOP>, which is a metaclass system
240 for Perl 5. This means that Moose not only makes building normal
241 Perl 5 objects better, but it also provides the power of metaclass
244 =head2 What does Moose stand for??
246 Moose doesn't stand for one thing in particular, however, if you
247 want, here are a few of my favorites, feel free to contribute
252 =item Make Other Object Systems Envious
254 =item Makes Object Orientation So Easy
256 =item Makes Object Orientation Spiffy- Er (sorry ingy)
258 =item Most Other Object Systems Emasculate
260 =item My Overcraft Overfilled (with) Some Eels
262 =item Moose Often Ovulate Sorta Early
264 =item Many Overloaded Object Systems Exists
266 =item Moose Offers Often Super Extensions
268 =item Meta Object Orientation Syntax Extensions
272 =head1 BUILDING CLASSES WITH MOOSE
274 Moose makes every attempt to provide as much convience during class
275 construction/definition, but still stay out of your way if you want
276 it to. Here are some of the features Moose provides:
278 Unless specified with C<extends>, any class which uses Moose will
279 inherit from L<Moose::Object>.
281 Moose will also manage all attributes (including inherited ones) that
282 are defined with C<has>. And assuming that you call C<new> which is
283 inherited from L<Moose::Object>, then this includes properly initializing
284 all instance slots, setting defaults where approprtiate and performing any
285 type constraint checking or coercion.
287 For more details, see the ever expanding L<Moose::Cookbook>.
289 =head1 EXPORTED FUNCTIONS
291 Moose will export a number of functions into the class's namespace, which
292 can then be used to set up the class. These functions all work directly
293 on the current class.
299 This is a method which provides access to the current class's metaclass.
301 =item B<extends (@superclasses)>
303 This function will set the superclass(es) for the current class.
305 This approach is recommended instead of C<use base>, because C<use base>
306 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
307 replace it. This is important to ensure that classes which do not have
308 superclasses properly inherit from L<Moose::Object>.
310 =item B<with ($role)>
312 This will apply a given C<$role> to the local class. Role support is
313 currently very experimental, see L<Moose::Role> for more details.
315 =item B<has ($name, %options)>
317 This will install an attribute of a given C<$name> into the current class.
318 The list of C<%options> are the same as those provided by both
319 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
320 few convience ones provided by Moose which are listed below:
324 =item I<is =E<gt> 'rw'|'ro'>
326 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
327 only). These will create either a read/write accessor or a read-only
328 accessor respectively, using the same name as the C<$name> of the attribute.
330 If you need more control over how your accessors are named, you can use the
331 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
333 =item I<isa =E<gt> $type_name>
335 The I<isa> option uses Moose's type constraint facilities to set up runtime
336 type checking for this attribute. Moose will perform the checks during class
337 construction, and within any accessors. The C<$type_name> argument must be a
338 string. The string can be either a class name, or a type defined using
339 Moose's type defintion features.
343 =item B<before $name|@names =E<gt> sub { ... }>
345 =item B<after $name|@names =E<gt> sub { ... }>
347 =item B<around $name|@names =E<gt> sub { ... }>
349 This three items are syntactic sugar for the before, after and around method
350 modifier features that L<Class::MOP> provides. More information on these can
351 be found in the L<Class::MOP> documentation for now.
355 The keyword C<super> is a noop when called outside of an C<override> method. In
356 the context of an C<override> method, it will call the next most appropriate
357 superclass method with the same arguments as the original method.
359 =item B<override ($name, &sub)>
361 An C<override> method, is a way of explictly saying "I am overriding this
362 method from my superclass". You can call C<super> within this method, and
363 it will work as expected. The same thing I<can> be accomplished with a normal
364 method call and the C<SUPER::> pseudo-package, it is really your choice.
368 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
369 an C<augment> method. You can think of C<inner> as being the inverse of
370 C<super>, the details of how C<inner> and C<augment> work is best described in
371 the L<Moose::Cookbook>.
373 =item B<augment ($name, &sub)>
375 An C<augment> method, is a way of explictly saying "I am augmenting this
376 method from my superclass". Once again, the details of how C<inner> and
377 C<augment> work is best described in the L<Moose::Cookbook>.
381 This is the C<Carp::confess> function, and exported here beause I use it
382 all the time. This feature may change in the future, so you have been warned.
386 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
387 use it all the time. It is highly recommended that this is used instead of
388 C<ref> anywhere you need to test for an object's class name.
398 It should be noted that C<super> and C<inner> can B<not> be used in the same
399 method. However, they can be combined together with the same class hierarchy,
400 see F<t/014_override_augment_inner_super.t> for an example.
402 The reason that this is so is because C<super> is only valid within a method
403 with the C<override> modifier, and C<inner> will never be valid within an
404 C<override> method. In fact, C<augment> will skip over any C<override> methods
405 when searching for it's appropriate C<inner>.
407 This might seem like a restriction, but I am of the opinion that keeping these
408 two features seperate (but interoperable) actually makes them easy to use since
409 their behavior is then easier to predict. Time will tell if I am right or not.
413 =head1 ACKNOWLEDGEMENTS
417 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
419 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
421 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
422 and it certainly wouldn't have this name ;P
424 =item The basis of the TypeContraints module was Rob Kinyon's idea
425 originally, I just ran with it.
427 =item Thanks to mst & chansen and the whole #moose poose for all the
428 ideas/feature-requests/encouragement
436 =item L<Class::MOP> documentation
438 =item The #moose channel on irc.perl.org
440 =item L<http://forum2.org/moose/>
442 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
444 This paper (suggested by lbr on #moose) was what lead to the implementation
445 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
446 want to understand this feature, I suggest you read this.
452 All complex software has bugs lurking in it, and this module is no
453 exception. If you find a bug please either email me, or add the bug
458 Stevan Little E<lt>stevan@iinteractive.comE<gt>
460 =head1 COPYRIGHT AND LICENSE
462 Copyright 2006 by Infinity Interactive, Inc.
464 L<http://www.iinteractive.com>
466 This library is free software; you can redistribute it and/or modify
467 it under the same terms as Perl itself.