7 our $VERSION = '0.03_02';
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) };
38 if ($pkg->can('meta')) {
40 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
41 || confess "Whoops, not møøsey enough";
44 $meta = Moose::Meta::Class->initialize($pkg => (
45 ':attribute_metaclass' => 'Moose::Meta::Attribute'
47 $meta->add_method('meta' => sub {
48 # re-initialize so it inherits properly
49 Moose::Meta::Class->initialize($pkg => (
50 ':attribute_metaclass' => 'Moose::Meta::Attribute'
56 # &alias_method will install the method, but it
57 # will not name it with
60 $meta->alias_method('extends' => subname 'Moose::extends' => sub {
61 _load_all_classes(@_);
62 $meta->superclasses(@_)
66 $meta->alias_method('with' => subname 'Moose::with' => sub {
68 _load_all_classes($role);
69 $role->meta->apply($meta);
73 $meta->alias_method('has' => subname 'Moose::has' => sub {
74 my ($name, %options) = @_;
75 $meta->add_attribute($name, %options)
78 # handle method modifers
79 $meta->alias_method('before' => subname 'Moose::before' => sub {
81 $meta->add_before_method_modifier($_, $code) for @_;
83 $meta->alias_method('after' => subname 'Moose::after' => sub {
85 $meta->add_after_method_modifier($_, $code) for @_;
87 $meta->alias_method('around' => subname 'Moose::around' => sub {
89 $meta->add_around_method_modifier($_, $code) for @_;
92 $meta->alias_method('super' => subname 'Moose::super' => sub {});
93 $meta->alias_method('override' => subname 'Moose::override' => sub {
94 my ($name, $method) = @_;
95 $meta->add_override_method_modifier($name => $method);
98 $meta->alias_method('inner' => subname 'Moose::inner' => sub {});
99 $meta->alias_method('augment' => subname 'Moose::augment' => sub {
100 my ($name, $method) = @_;
101 $meta->add_augment_method_modifier($name => $method);
104 # make sure they inherit from Moose::Object
105 $meta->superclasses('Moose::Object')
106 unless $meta->superclasses();
108 # we recommend using these things
109 # so export them for them
110 $meta->alias_method('confess' => \&Carp::confess);
111 $meta->alias_method('blessed' => \&Scalar::Util::blessed);
116 sub _load_all_classes {
117 foreach my $super (@_) {
118 # see if this is already
119 # loaded in the symbol table
120 next if _is_class_already_loaded($super);
121 # otherwise require it ...
123 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
127 sub _is_class_already_loaded {
130 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
131 foreach (keys %{"${name}::"}) {
132 next if substr($_, -2, 2) eq '::';
133 return 1 if defined &{"${name}::$_"};
146 Moose - Moose, it's the new Camel
153 has 'x' => (isa => 'Int', is => 'rw');
154 has 'y' => (isa => 'Int', is => 'rw');
167 has 'z' => (isa => 'Int');
169 after 'clear' => sub {
176 This is an early release of this module, it still needs
177 some fine tuning and B<lots> more documentation. I am adopting
178 the I<release early and release often> approach with this module,
179 so keep an eye on your favorite CPAN mirror!
183 Moose is an extension of the Perl 5 object system.
185 =head2 Another object system!?!?
187 Yes, I know there has been an explosion recently of new ways to
188 build object's in Perl 5, most of them based on inside-out objects,
189 and other such things. Moose is different because it is not a new
190 object system for Perl 5, but instead an extension of the existing
193 Moose is built on top of L<Class::MOP>, which is a metaclass system
194 for Perl 5. This means that Moose not only makes building normal
195 Perl 5 objects better, but it also provides the power of metaclass
198 =head2 What does Moose stand for??
200 Moose doesn't stand for one thing in particular, however, if you
201 want, here are a few of my favorites, feel free to contribute
206 =item Make Other Object Systems Envious
208 =item Makes Object Orientation So Easy
210 =item Makes Object Orientation Spiffy- Er (sorry ingy)
212 =item Most Other Object Systems Emasculate
214 =item My Overcraft Overfilled (with) Some Eels
216 =item Moose Often Ovulate Sorta Early
218 =item Many Overloaded Object Systems Exists
220 =item Moose Offers Often Super Extensions
224 =head1 BUILDING CLASSES WITH MOOSE
226 Moose makes every attempt to provide as much convience during class
227 construction/definition, but still stay out of your way if you want
228 it to. Here are some of the features Moose provides:
230 Unless specified with C<extends>, any class which uses Moose will
231 inherit from L<Moose::Object>.
233 Moose will also manage all attributes (including inherited ones) that
234 are defined with C<has>. And assuming that you call C<new> which is
235 inherited from L<Moose::Object>, then this includes properly initializing
236 all instance slots, setting defaults where approprtiate and performing any
237 type constraint checking or coercion.
239 For more details, see the ever expanding L<Moose::Cookbook>.
241 =head1 EXPORTED FUNCTIONS
243 Moose will export a number of functions into the class's namespace, which
244 can then be used to set up the class. These functions all work directly
245 on the current class.
251 This is a method which provides access to the current class's metaclass.
253 =item B<extends (@superclasses)>
255 This function will set the superclass(es) for the current class.
257 This approach is recommended instead of C<use base>, because C<use base>
258 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
259 replace it. This is important to ensure that classes which do not have
260 superclasses properly inherit from L<Moose::Object>.
262 =item B<with ($role)>
264 This will apply a given C<$role> to the local class. Role support is
265 currently very experimental, see L<Moose::Role> for more details.
267 =item B<has ($name, %options)>
269 This will install an attribute of a given C<$name> into the current class.
270 The list of C<%options> are the same as those provided by both
271 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
272 few convience ones provided by Moose which are listed below:
276 =item I<is =E<gt> 'rw'|'ro'>
278 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
279 only). These will create either a read/write accessor or a read-only
280 accessor respectively, using the same name as the C<$name> of the attribute.
282 If you need more control over how your accessors are named, you can use the
283 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
285 =item I<isa =E<gt> $type_name>
287 The I<isa> option uses Moose's type constraint facilities to set up runtime
288 type checking for this attribute. Moose will perform the checks during class
289 construction, and within any accessors. The C<$type_name> argument must be a
290 string. The string can be either a class name, or a type defined using
291 Moose's type defintion features.
295 =item B<before $name|@names =E<gt> sub { ... }>
297 =item B<after $name|@names =E<gt> sub { ... }>
299 =item B<around $name|@names =E<gt> sub { ... }>
301 This three items are syntactic sugar for the before, after and around method
302 modifier features that L<Class::MOP> provides. More information on these can
303 be found in the L<Class::MOP> documentation for now.
307 The keyword C<super> is a noop when called outside of an C<override> method. In
308 the context of an C<override> method, it will call the next most appropriate
309 superclass method with the same arguments as the original method.
311 =item B<override ($name, &sub)>
313 An C<override> method, is a way of explictly saying "I am overriding this
314 method from my superclass". You can call C<super> within this method, and
315 it will work as expected. The same thing I<can> be accomplished with a normal
316 method call and the C<SUPER::> pseudo-package, it is really your choice.
320 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
321 an C<augment> method. You can think of C<inner> as being the inverse of
322 C<super>, the details of how C<inner> and C<augment> work is best described in
323 the L<Moose::Cookbook>.
325 =item B<augment ($name, &sub)>
327 An C<augment> method, is a way of explictly saying "I am augmenting this
328 method from my superclass". Once again, the details of how C<inner> and
329 C<augment> work is best described in the L<Moose::Cookbook>.
333 This is the C<Carp::confess> function, and exported here beause I use it
334 all the time. This feature may change in the future, so you have been warned.
338 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
339 use it all the time. It is highly recommended that this is used instead of
340 C<ref> anywhere you need to test for an object's class name.
350 It should be noted that C<super> and C<inner> can B<not> be used in the same
351 method. However, they can be combined together with the same class hierarchy,
352 see F<t/014_override_augment_inner_super.t> for an example.
354 The reason that this is so is because C<super> is only valid within a method
355 with the C<override> modifier, and C<inner> will never be valid within an
356 C<override> method. In fact, C<augment> will skip over any C<override> methods
357 when searching for it's appropriate C<inner>.
359 This might seem like a restriction, but I am of the opinion that keeping these
360 two features seperate (but interoperable) actually makes them easy to use since
361 their behavior is then easier to predict. Time will tell if I am right or not.
365 =head1 ACKNOWLEDGEMENTS
369 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
371 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
373 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
374 and it certainly wouldn't have this name ;P
376 =item The basis of the TypeContraints module was Rob Kinyon's idea
377 originally, I just ran with it.
379 =item Thanks to mst & chansen and the whole #moose poose for all the
380 ideas/feature-requests/encouragement
388 =item L<Class::MOP> documentation
390 =item The #moose channel on irc.perl.org
392 =item L<http://forum2.org/moose/>
394 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
396 This paper (suggested by lbr on #moose) was what lead to the implementation
397 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
398 want to understand this feature, I suggest you read this.
404 All complex software has bugs lurking in it, and this module is no
405 exception. If you find a bug please either email me, or add the bug
410 Stevan Little E<lt>stevan@iinteractive.comE<gt>
412 =head1 COPYRIGHT AND LICENSE
414 Copyright 2006 by Infinity Interactive, Inc.
416 L<http://www.iinteractive.com>
418 This library is free software; you can redistribute it and/or modify
419 it under the same terms as Perl itself.