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 ':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;
67 my $meta = _find_meta();
68 return subname 'Moose::extends' => sub {
69 _load_all_classes(@_);
70 $meta->superclasses(@_)
74 my $meta = _find_meta();
75 return subname 'Moose::with' => sub {
77 _load_all_classes($role);
78 $role->meta->apply($meta);
82 my $meta = _find_meta();
83 return subname 'Moose::has' => sub {
84 my ($name, %options) = @_;
85 if ($options{metaclass}) {
86 $meta->add_attribute($options{metaclass}->new($name, %options));
89 $meta->add_attribute($name, %options);
94 my $meta = _find_meta();
95 return subname 'Moose::before' => sub {
97 $meta->add_before_method_modifier($_, $code) for @_;
101 my $meta = _find_meta();
102 return subname 'Moose::after' => sub {
104 $meta->add_after_method_modifier($_, $code) for @_;
108 my $meta = _find_meta();
109 return subname 'Moose::around' => sub {
111 $meta->add_around_method_modifier($_, $code) for @_;
115 my $meta = _find_meta();
116 return subname 'Moose::super' => sub {};
119 my $meta = _find_meta();
120 return subname 'Moose::override' => sub {
121 my ($name, $method) = @_;
122 $meta->add_override_method_modifier($name => $method);
126 my $meta = _find_meta();
127 return subname 'Moose::inner' => sub {};
130 my $meta = _find_meta();
131 return subname 'Moose::augment' => sub {
132 my ($name, $method) = @_;
133 $meta->add_augment_method_modifier($name => $method);
137 return \&Carp::confess;
140 return \&Scalar::Util::blessed;
144 my $exporter = Sub::Exporter::build_exporter({
145 exports => \%exports,
154 # we should never export to main
155 return if $CALLER eq 'main';
163 sub _load_all_classes {
164 foreach my $super (@_) {
165 # see if this is already
166 # loaded in the symbol table
167 next if _is_class_already_loaded($super);
168 # otherwise require it ...
170 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
174 sub _is_class_already_loaded {
177 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
178 foreach (keys %{"${name}::"}) {
179 next if substr($_, -2, 2) eq '::';
180 return 1 if defined &{"${name}::$_"};
193 Moose - Moose, it's the new Camel
200 has 'x' => (isa => 'Int', is => 'rw');
201 has 'y' => (isa => 'Int', is => 'rw');
214 has 'z' => (isa => 'Int');
216 after 'clear' => sub {
223 This is an early release of this module, it still needs
224 some fine tuning and B<lots> more documentation. I am adopting
225 the I<release early and release often> approach with this module,
226 so keep an eye on your favorite CPAN mirror!
230 Moose is an extension of the Perl 5 object system.
232 =head2 Another object system!?!?
234 Yes, I know there has been an explosion recently of new ways to
235 build object's in Perl 5, most of them based on inside-out objects,
236 and other such things. Moose is different because it is not a new
237 object system for Perl 5, but instead an extension of the existing
240 Moose is built on top of L<Class::MOP>, which is a metaclass system
241 for Perl 5. This means that Moose not only makes building normal
242 Perl 5 objects better, but it also provides the power of metaclass
245 =head2 What does Moose stand for??
247 Moose doesn't stand for one thing in particular, however, if you
248 want, here are a few of my favorites, feel free to contribute
253 =item Make Other Object Systems Envious
255 =item Makes Object Orientation So Easy
257 =item Makes Object Orientation Spiffy- Er (sorry ingy)
259 =item Most Other Object Systems Emasculate
261 =item My Overcraft Overfilled (with) Some Eels
263 =item Moose Often Ovulate Sorta Early
265 =item Many Overloaded Object Systems Exists
267 =item Moose Offers Often Super Extensions
269 =item Meta Object Orientation Syntax Extensions
273 =head1 BUILDING CLASSES WITH MOOSE
275 Moose makes every attempt to provide as much convience during class
276 construction/definition, but still stay out of your way if you want
277 it to. Here are some of the features Moose provides:
279 Unless specified with C<extends>, any class which uses Moose will
280 inherit from L<Moose::Object>.
282 Moose will also manage all attributes (including inherited ones) that
283 are defined with C<has>. And assuming that you call C<new> which is
284 inherited from L<Moose::Object>, then this includes properly initializing
285 all instance slots, setting defaults where approprtiate and performing any
286 type constraint checking or coercion.
288 For more details, see the ever expanding L<Moose::Cookbook>.
290 =head1 EXPORTED FUNCTIONS
292 Moose will export a number of functions into the class's namespace, which
293 can then be used to set up the class. These functions all work directly
294 on the current class.
300 This is a method which provides access to the current class's metaclass.
302 =item B<extends (@superclasses)>
304 This function will set the superclass(es) for the current class.
306 This approach is recommended instead of C<use base>, because C<use base>
307 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
308 replace it. This is important to ensure that classes which do not have
309 superclasses properly inherit from L<Moose::Object>.
311 =item B<with ($role)>
313 This will apply a given C<$role> to the local class. Role support is
314 currently very experimental, see L<Moose::Role> for more details.
316 =item B<has ($name, %options)>
318 This will install an attribute of a given C<$name> into the current class.
319 The list of C<%options> are the same as those provided by both
320 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
321 few convience ones provided by Moose which are listed below:
325 =item I<is =E<gt> 'rw'|'ro'>
327 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
328 only). These will create either a read/write accessor or a read-only
329 accessor respectively, using the same name as the C<$name> of the attribute.
331 If you need more control over how your accessors are named, you can use the
332 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
334 =item I<isa =E<gt> $type_name>
336 The I<isa> option uses Moose's type constraint facilities to set up runtime
337 type checking for this attribute. Moose will perform the checks during class
338 construction, and within any accessors. The C<$type_name> argument must be a
339 string. The string can be either a class name, or a type defined using
340 Moose's type defintion features.
344 =item B<before $name|@names =E<gt> sub { ... }>
346 =item B<after $name|@names =E<gt> sub { ... }>
348 =item B<around $name|@names =E<gt> sub { ... }>
350 This three items are syntactic sugar for the before, after and around method
351 modifier features that L<Class::MOP> provides. More information on these can
352 be found in the L<Class::MOP> documentation for now.
356 The keyword C<super> is a noop when called outside of an C<override> method. In
357 the context of an C<override> method, it will call the next most appropriate
358 superclass method with the same arguments as the original method.
360 =item B<override ($name, &sub)>
362 An C<override> method, is a way of explictly saying "I am overriding this
363 method from my superclass". You can call C<super> within this method, and
364 it will work as expected. The same thing I<can> be accomplished with a normal
365 method call and the C<SUPER::> pseudo-package, it is really your choice.
369 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
370 an C<augment> method. You can think of C<inner> as being the inverse of
371 C<super>, the details of how C<inner> and C<augment> work is best described in
372 the L<Moose::Cookbook>.
374 =item B<augment ($name, &sub)>
376 An C<augment> method, is a way of explictly saying "I am augmenting this
377 method from my superclass". Once again, the details of how C<inner> and
378 C<augment> work is best described in the L<Moose::Cookbook>.
382 This is the C<Carp::confess> function, and exported here beause I use it
383 all the time. This feature may change in the future, so you have been warned.
387 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
388 use it all the time. It is highly recommended that this is used instead of
389 C<ref> anywhere you need to test for an object's class name.
399 It should be noted that C<super> and C<inner> can B<not> be used in the same
400 method. However, they can be combined together with the same class hierarchy,
401 see F<t/014_override_augment_inner_super.t> for an example.
403 The reason that this is so is because C<super> is only valid within a method
404 with the C<override> modifier, and C<inner> will never be valid within an
405 C<override> method. In fact, C<augment> will skip over any C<override> methods
406 when searching for it's appropriate C<inner>.
408 This might seem like a restriction, but I am of the opinion that keeping these
409 two features seperate (but interoperable) actually makes them easy to use since
410 their behavior is then easier to predict. Time will tell if I am right or not.
414 =head1 ACKNOWLEDGEMENTS
418 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
420 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
422 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
423 and it certainly wouldn't have this name ;P
425 =item The basis of the TypeContraints module was Rob Kinyon's idea
426 originally, I just ran with it.
428 =item Thanks to mst & chansen and the whole #moose poose for all the
429 ideas/feature-requests/encouragement
437 =item L<Class::MOP> documentation
439 =item The #moose channel on irc.perl.org
441 =item L<http://forum2.org/moose/>
443 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
445 This paper (suggested by lbr on #moose) was what lead to the implementation
446 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
447 want to understand this feature, I suggest you read this.
453 All complex software has bugs lurking in it, and this module is no
454 exception. If you find a bug please either email me, or add the bug
459 Stevan Little E<lt>stevan@iinteractive.comE<gt>
461 =head1 COPYRIGHT AND LICENSE
463 Copyright 2006 by Infinity Interactive, Inc.
465 L<http://www.iinteractive.com>
467 This library is free software; you can redistribute it and/or modify
468 it under the same terms as Perl itself.