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;
29 # we should never export to main
30 return if $pkg eq 'main';
32 # make a subtype for each Moose class
35 => where { $_->isa($pkg) }
36 unless find_type_constraint($pkg);
39 if ($pkg->can('meta')) {
41 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
42 || confess "Whoops, not møøsey enough";
45 $meta = Moose::Meta::Class->initialize($pkg => (
46 ':attribute_metaclass' => 'Moose::Meta::Attribute'
48 $meta->add_method('meta' => sub {
49 # re-initialize so it inherits properly
50 Moose::Meta::Class->initialize($pkg => (
51 ':attribute_metaclass' => 'Moose::Meta::Attribute'
57 # &alias_method will install the method, but it
58 # will not name it with
61 $meta->alias_method('extends' => subname 'Moose::extends' => sub {
62 _load_all_classes(@_);
63 $meta->superclasses(@_)
67 $meta->alias_method('with' => subname 'Moose::with' => sub {
69 _load_all_classes($role);
70 $role->meta->apply($meta);
74 $meta->alias_method('has' => subname 'Moose::has' => sub {
75 my ($name, %options) = @_;
76 $meta->add_attribute($name, %options)
79 # handle method modifers
80 $meta->alias_method('before' => subname 'Moose::before' => sub {
82 $meta->add_before_method_modifier($_, $code) for @_;
84 $meta->alias_method('after' => subname 'Moose::after' => sub {
86 $meta->add_after_method_modifier($_, $code) for @_;
88 $meta->alias_method('around' => subname 'Moose::around' => sub {
90 $meta->add_around_method_modifier($_, $code) for @_;
93 $meta->alias_method('super' => subname 'Moose::super' => sub {});
94 $meta->alias_method('override' => subname 'Moose::override' => sub {
95 my ($name, $method) = @_;
96 $meta->add_override_method_modifier($name => $method);
99 $meta->alias_method('inner' => subname 'Moose::inner' => sub {});
100 $meta->alias_method('augment' => subname 'Moose::augment' => sub {
101 my ($name, $method) = @_;
102 $meta->add_augment_method_modifier($name => $method);
105 # make sure they inherit from Moose::Object
106 $meta->superclasses('Moose::Object')
107 unless $meta->superclasses();
109 # we recommend using these things
110 # so export them for them
111 $meta->alias_method('confess' => \&Carp::confess);
112 $meta->alias_method('blessed' => \&Scalar::Util::blessed);
117 sub _load_all_classes {
118 foreach my $super (@_) {
119 # see if this is already
120 # loaded in the symbol table
121 next if _is_class_already_loaded($super);
122 # otherwise require it ...
124 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
128 sub _is_class_already_loaded {
131 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
132 foreach (keys %{"${name}::"}) {
133 next if substr($_, -2, 2) eq '::';
134 return 1 if defined &{"${name}::$_"};
147 Moose - Moose, it's the new Camel
154 has 'x' => (isa => 'Int', is => 'rw');
155 has 'y' => (isa => 'Int', is => 'rw');
168 has 'z' => (isa => 'Int');
170 after 'clear' => sub {
177 This is an early release of this module, it still needs
178 some fine tuning and B<lots> more documentation. I am adopting
179 the I<release early and release often> approach with this module,
180 so keep an eye on your favorite CPAN mirror!
184 Moose is an extension of the Perl 5 object system.
186 =head2 Another object system!?!?
188 Yes, I know there has been an explosion recently of new ways to
189 build object's in Perl 5, most of them based on inside-out objects,
190 and other such things. Moose is different because it is not a new
191 object system for Perl 5, but instead an extension of the existing
194 Moose is built on top of L<Class::MOP>, which is a metaclass system
195 for Perl 5. This means that Moose not only makes building normal
196 Perl 5 objects better, but it also provides the power of metaclass
199 =head2 What does Moose stand for??
201 Moose doesn't stand for one thing in particular, however, if you
202 want, here are a few of my favorites, feel free to contribute
207 =item Make Other Object Systems Envious
209 =item Makes Object Orientation So Easy
211 =item Makes Object Orientation Spiffy- Er (sorry ingy)
213 =item Most Other Object Systems Emasculate
215 =item My Overcraft Overfilled (with) Some Eels
217 =item Moose Often Ovulate Sorta Early
219 =item Many Overloaded Object Systems Exists
221 =item Moose Offers Often Super Extensions
223 =item Meta Object Orientation Syntax Extensions
227 =head1 BUILDING CLASSES WITH MOOSE
229 Moose makes every attempt to provide as much convience during class
230 construction/definition, but still stay out of your way if you want
231 it to. Here are some of the features Moose provides:
233 Unless specified with C<extends>, any class which uses Moose will
234 inherit from L<Moose::Object>.
236 Moose will also manage all attributes (including inherited ones) that
237 are defined with C<has>. And assuming that you call C<new> which is
238 inherited from L<Moose::Object>, then this includes properly initializing
239 all instance slots, setting defaults where approprtiate and performing any
240 type constraint checking or coercion.
242 For more details, see the ever expanding L<Moose::Cookbook>.
244 =head1 EXPORTED FUNCTIONS
246 Moose will export a number of functions into the class's namespace, which
247 can then be used to set up the class. These functions all work directly
248 on the current class.
254 This is a method which provides access to the current class's metaclass.
256 =item B<extends (@superclasses)>
258 This function will set the superclass(es) for the current class.
260 This approach is recommended instead of C<use base>, because C<use base>
261 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
262 replace it. This is important to ensure that classes which do not have
263 superclasses properly inherit from L<Moose::Object>.
265 =item B<with ($role)>
267 This will apply a given C<$role> to the local class. Role support is
268 currently very experimental, see L<Moose::Role> for more details.
270 =item B<has ($name, %options)>
272 This will install an attribute of a given C<$name> into the current class.
273 The list of C<%options> are the same as those provided by both
274 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
275 few convience ones provided by Moose which are listed below:
279 =item I<is =E<gt> 'rw'|'ro'>
281 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
282 only). These will create either a read/write accessor or a read-only
283 accessor respectively, using the same name as the C<$name> of the attribute.
285 If you need more control over how your accessors are named, you can use the
286 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
288 =item I<isa =E<gt> $type_name>
290 The I<isa> option uses Moose's type constraint facilities to set up runtime
291 type checking for this attribute. Moose will perform the checks during class
292 construction, and within any accessors. The C<$type_name> argument must be a
293 string. The string can be either a class name, or a type defined using
294 Moose's type defintion features.
298 =item B<before $name|@names =E<gt> sub { ... }>
300 =item B<after $name|@names =E<gt> sub { ... }>
302 =item B<around $name|@names =E<gt> sub { ... }>
304 This three items are syntactic sugar for the before, after and around method
305 modifier features that L<Class::MOP> provides. More information on these can
306 be found in the L<Class::MOP> documentation for now.
310 The keyword C<super> is a noop when called outside of an C<override> method. In
311 the context of an C<override> method, it will call the next most appropriate
312 superclass method with the same arguments as the original method.
314 =item B<override ($name, &sub)>
316 An C<override> method, is a way of explictly saying "I am overriding this
317 method from my superclass". You can call C<super> within this method, and
318 it will work as expected. The same thing I<can> be accomplished with a normal
319 method call and the C<SUPER::> pseudo-package, it is really your choice.
323 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
324 an C<augment> method. You can think of C<inner> as being the inverse of
325 C<super>, the details of how C<inner> and C<augment> work is best described in
326 the L<Moose::Cookbook>.
328 =item B<augment ($name, &sub)>
330 An C<augment> method, is a way of explictly saying "I am augmenting this
331 method from my superclass". Once again, the details of how C<inner> and
332 C<augment> work is best described in the L<Moose::Cookbook>.
336 This is the C<Carp::confess> function, and exported here beause I use it
337 all the time. This feature may change in the future, so you have been warned.
341 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
342 use it all the time. It is highly recommended that this is used instead of
343 C<ref> anywhere you need to test for an object's class name.
353 It should be noted that C<super> and C<inner> can B<not> be used in the same
354 method. However, they can be combined together with the same class hierarchy,
355 see F<t/014_override_augment_inner_super.t> for an example.
357 The reason that this is so is because C<super> is only valid within a method
358 with the C<override> modifier, and C<inner> will never be valid within an
359 C<override> method. In fact, C<augment> will skip over any C<override> methods
360 when searching for it's appropriate C<inner>.
362 This might seem like a restriction, but I am of the opinion that keeping these
363 two features seperate (but interoperable) actually makes them easy to use since
364 their behavior is then easier to predict. Time will tell if I am right or not.
368 =head1 ACKNOWLEDGEMENTS
372 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
374 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
376 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
377 and it certainly wouldn't have this name ;P
379 =item The basis of the TypeContraints module was Rob Kinyon's idea
380 originally, I just ran with it.
382 =item Thanks to mst & chansen and the whole #moose poose for all the
383 ideas/feature-requests/encouragement
391 =item L<Class::MOP> documentation
393 =item The #moose channel on irc.perl.org
395 =item L<http://forum2.org/moose/>
397 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
399 This paper (suggested by lbr on #moose) was what lead to the implementation
400 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
401 want to understand this feature, I suggest you read this.
407 All complex software has bugs lurking in it, and this module is no
408 exception. If you find a bug please either email me, or add the bug
413 Stevan Little E<lt>stevan@iinteractive.comE<gt>
415 =head1 COPYRIGHT AND LICENSE
417 Copyright 2006 by Infinity Interactive, Inc.
419 L<http://www.iinteractive.com>
421 This library is free software; you can redistribute it and/or modify
422 it under the same terms as Perl itself.