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;
24 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 $meta->add_method('meta' => sub {
49 # re-initialize so it inherits properly
50 Moose::Meta::Class->initialize($class);
54 # make sure they inherit from Moose::Object
55 $meta->superclasses('Moose::Object')
56 unless $meta->superclasses();
58 return $METAS{$class} = $meta;
63 my $meta = _find_meta();
64 return subname 'Moose::extends' => sub {
65 _load_all_classes(@_);
66 $meta->superclasses(@_)
70 my $meta = _find_meta();
71 return subname 'Moose::with' => sub {
73 _load_all_classes($role);
74 $role->meta->apply($meta);
78 my $meta = _find_meta();
79 return subname 'Moose::has' => sub {
80 my ($name, %options) = @_;
81 if ($options{metaclass}) {
82 _load_all_classes($options{metaclass});
83 $meta->add_attribute($options{metaclass}->new($name, %options));
86 $meta->add_attribute($name, %options);
91 my $meta = _find_meta();
92 return subname 'Moose::before' => sub {
94 $meta->add_before_method_modifier($_, $code) for @_;
98 my $meta = _find_meta();
99 return subname 'Moose::after' => sub {
101 $meta->add_after_method_modifier($_, $code) for @_;
105 my $meta = _find_meta();
106 return subname 'Moose::around' => sub {
108 $meta->add_around_method_modifier($_, $code) for @_;
112 my $meta = _find_meta();
113 return subname 'Moose::super' => sub {};
116 my $meta = _find_meta();
117 return subname 'Moose::override' => sub {
118 my ($name, $method) = @_;
119 $meta->add_override_method_modifier($name => $method);
123 my $meta = _find_meta();
124 return subname 'Moose::inner' => sub {};
127 my $meta = _find_meta();
128 return subname 'Moose::augment' => sub {
129 my ($name, $method) = @_;
130 $meta->add_augment_method_modifier($name => $method);
134 return \&Carp::confess;
137 return \&Scalar::Util::blessed;
141 my $exporter = Sub::Exporter::build_exporter({
142 exports => \%exports,
151 # we should never export to main
152 return if $CALLER eq 'main';
160 sub _load_all_classes {
161 foreach my $super (@_) {
162 # see if this is already
163 # loaded in the symbol table
164 next if _is_class_already_loaded($super);
165 # otherwise require it ...
167 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
171 sub _is_class_already_loaded {
174 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
175 foreach (keys %{"${name}::"}) {
176 next if substr($_, -2, 2) eq '::';
177 return 1 if defined &{"${name}::$_"};
190 Moose - Moose, it's the new Camel
197 has 'x' => (isa => 'Int', is => 'rw');
198 has 'y' => (isa => 'Int', is => 'rw');
211 has 'z' => (isa => 'Int');
213 after 'clear' => sub {
220 This is an early release of this module, it still needs
221 some fine tuning and B<lots> more documentation. I am adopting
222 the I<release early and release often> approach with this module,
223 so keep an eye on your favorite CPAN mirror!
227 Moose is an extension of the Perl 5 object system.
229 =head2 Another object system!?!?
231 Yes, I know there has been an explosion recently of new ways to
232 build object's in Perl 5, most of them based on inside-out objects,
233 and other such things. Moose is different because it is not a new
234 object system for Perl 5, but instead an extension of the existing
237 Moose is built on top of L<Class::MOP>, which is a metaclass system
238 for Perl 5. This means that Moose not only makes building normal
239 Perl 5 objects better, but it also provides the power of metaclass
242 =head2 What does Moose stand for??
244 Moose doesn't stand for one thing in particular, however, if you
245 want, here are a few of my favorites, feel free to contribute
250 =item Make Other Object Systems Envious
252 =item Makes Object Orientation So Easy
254 =item Makes Object Orientation Spiffy- Er (sorry ingy)
256 =item Most Other Object Systems Emasculate
258 =item My Overcraft Overfilled (with) Some Eels
260 =item Moose Often Ovulate Sorta Early
262 =item Many Overloaded Object Systems Exists
264 =item Moose Offers Often Super Extensions
266 =item Meta Object Orientation Syntax Extensions
270 =head1 BUILDING CLASSES WITH MOOSE
272 Moose makes every attempt to provide as much convience during class
273 construction/definition, but still stay out of your way if you want
274 it to. Here are some of the features Moose provides:
276 Unless specified with C<extends>, any class which uses Moose will
277 inherit from L<Moose::Object>.
279 Moose will also manage all attributes (including inherited ones) that
280 are defined with C<has>. And assuming that you call C<new> which is
281 inherited from L<Moose::Object>, then this includes properly initializing
282 all instance slots, setting defaults where approprtiate and performing any
283 type constraint checking or coercion.
285 For more details, see the ever expanding L<Moose::Cookbook>.
287 =head1 EXPORTED FUNCTIONS
289 Moose will export a number of functions into the class's namespace, which
290 can then be used to set up the class. These functions all work directly
291 on the current class.
297 This is a method which provides access to the current class's metaclass.
299 =item B<extends (@superclasses)>
301 This function will set the superclass(es) for the current class.
303 This approach is recommended instead of C<use base>, because C<use base>
304 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
305 replace it. This is important to ensure that classes which do not have
306 superclasses properly inherit from L<Moose::Object>.
308 =item B<with ($role)>
310 This will apply a given C<$role> to the local class. Role support is
311 currently very experimental, see L<Moose::Role> for more details.
313 =item B<has ($name, %options)>
315 This will install an attribute of a given C<$name> into the current class.
316 The list of C<%options> are the same as those provided by both
317 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
318 few convience ones provided by Moose which are listed below:
322 =item I<is =E<gt> 'rw'|'ro'>
324 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
325 only). These will create either a read/write accessor or a read-only
326 accessor respectively, using the same name as the C<$name> of the attribute.
328 If you need more control over how your accessors are named, you can use the
329 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
331 =item I<isa =E<gt> $type_name>
333 The I<isa> option uses Moose's type constraint facilities to set up runtime
334 type checking for this attribute. Moose will perform the checks during class
335 construction, and within any accessors. The C<$type_name> argument must be a
336 string. The string can be either a class name, or a type defined using
337 Moose's type defintion features.
341 =item B<before $name|@names =E<gt> sub { ... }>
343 =item B<after $name|@names =E<gt> sub { ... }>
345 =item B<around $name|@names =E<gt> sub { ... }>
347 This three items are syntactic sugar for the before, after and around method
348 modifier features that L<Class::MOP> provides. More information on these can
349 be found in the L<Class::MOP> documentation for now.
353 The keyword C<super> is a noop when called outside of an C<override> method. In
354 the context of an C<override> method, it will call the next most appropriate
355 superclass method with the same arguments as the original method.
357 =item B<override ($name, &sub)>
359 An C<override> method, is a way of explictly saying "I am overriding this
360 method from my superclass". You can call C<super> within this method, and
361 it will work as expected. The same thing I<can> be accomplished with a normal
362 method call and the C<SUPER::> pseudo-package, it is really your choice.
366 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
367 an C<augment> method. You can think of C<inner> as being the inverse of
368 C<super>, the details of how C<inner> and C<augment> work is best described in
369 the L<Moose::Cookbook>.
371 =item B<augment ($name, &sub)>
373 An C<augment> method, is a way of explictly saying "I am augmenting this
374 method from my superclass". Once again, the details of how C<inner> and
375 C<augment> work is best described in the L<Moose::Cookbook>.
379 This is the C<Carp::confess> function, and exported here beause I use it
380 all the time. This feature may change in the future, so you have been warned.
384 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
385 use it all the time. It is highly recommended that this is used instead of
386 C<ref> anywhere you need to test for an object's class name.
396 It should be noted that C<super> and C<inner> can B<not> be used in the same
397 method. However, they can be combined together with the same class hierarchy,
398 see F<t/014_override_augment_inner_super.t> for an example.
400 The reason that this is so is because C<super> is only valid within a method
401 with the C<override> modifier, and C<inner> will never be valid within an
402 C<override> method. In fact, C<augment> will skip over any C<override> methods
403 when searching for it's appropriate C<inner>.
405 This might seem like a restriction, but I am of the opinion that keeping these
406 two features seperate (but interoperable) actually makes them easy to use since
407 their behavior is then easier to predict. Time will tell if I am right or not.
411 =head1 ACKNOWLEDGEMENTS
415 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
417 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
419 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
420 and it certainly wouldn't have this name ;P
422 =item The basis of the TypeContraints module was Rob Kinyon's idea
423 originally, I just ran with it.
425 =item Thanks to mst & chansen and the whole #moose poose for all the
426 ideas/feature-requests/encouragement
434 =item L<Class::MOP> documentation
436 =item The #moose channel on irc.perl.org
438 =item L<http://forum2.org/moose/>
440 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
442 This paper (suggested by lbr on #moose) was what lead to the implementation
443 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
444 want to understand this feature, I suggest you read this.
450 All complex software has bugs lurking in it, and this module is no
451 exception. If you find a bug please either email me, or add the bug
456 Stevan Little E<lt>stevan@iinteractive.comE<gt>
458 =head1 COPYRIGHT AND LICENSE
460 Copyright 2006 by Infinity Interactive, Inc.
462 L<http://www.iinteractive.com>
464 This library is free software; you can redistribute it and/or modify
465 it under the same terms as Perl itself.