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 ($name =~ /^\+(.*)/) {
85 if ($options{metaclass}) {
86 _load_all_classes($options{metaclass});
87 $meta->add_attribute($options{metaclass}->new($name, %options));
90 $meta->add_attribute($name, %options);
96 my $meta = _find_meta();
97 return subname 'Moose::before' => sub {
99 $meta->add_before_method_modifier($_, $code) for @_;
103 my $meta = _find_meta();
104 return subname 'Moose::after' => sub {
106 $meta->add_after_method_modifier($_, $code) for @_;
110 my $meta = _find_meta();
111 return subname 'Moose::around' => sub {
113 $meta->add_around_method_modifier($_, $code) for @_;
117 my $meta = _find_meta();
118 return subname 'Moose::super' => sub {};
121 my $meta = _find_meta();
122 return subname 'Moose::override' => sub {
123 my ($name, $method) = @_;
124 $meta->add_override_method_modifier($name => $method);
128 my $meta = _find_meta();
129 return subname 'Moose::inner' => sub {};
132 my $meta = _find_meta();
133 return subname 'Moose::augment' => sub {
134 my ($name, $method) = @_;
135 $meta->add_augment_method_modifier($name => $method);
139 return \&Carp::confess;
142 return \&Scalar::Util::blessed;
146 my $exporter = Sub::Exporter::build_exporter({
147 exports => \%exports,
156 # we should never export to main
157 return if $CALLER eq 'main';
165 sub _load_all_classes {
166 foreach my $super (@_) {
167 # see if this is already
168 # loaded in the symbol table
169 next if _is_class_already_loaded($super);
170 # otherwise require it ...
172 || confess "Could not load superclass '$super' because : " . $UNIVERSAL::require::ERROR;
176 sub _is_class_already_loaded {
179 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
180 foreach (keys %{"${name}::"}) {
181 next if substr($_, -2, 2) eq '::';
182 return 1 if defined &{"${name}::$_"};
195 Moose - Moose, it's the new Camel
202 has 'x' => (isa => 'Int', is => 'rw');
203 has 'y' => (isa => 'Int', is => 'rw');
216 has 'z' => (isa => 'Int');
218 after 'clear' => sub {
225 This is an early release of this module, it still needs
226 some fine tuning and B<lots> more documentation. I am adopting
227 the I<release early and release often> approach with this module,
228 so keep an eye on your favorite CPAN mirror!
232 Moose is an extension of the Perl 5 object system.
234 =head2 Another object system!?!?
236 Yes, I know there has been an explosion recently of new ways to
237 build object's in Perl 5, most of them based on inside-out objects,
238 and other such things. Moose is different because it is not a new
239 object system for Perl 5, but instead an extension of the existing
242 Moose is built on top of L<Class::MOP>, which is a metaclass system
243 for Perl 5. This means that Moose not only makes building normal
244 Perl 5 objects better, but it also provides the power of metaclass
247 =head2 What does Moose stand for??
249 Moose doesn't stand for one thing in particular, however, if you
250 want, here are a few of my favorites, feel free to contribute
255 =item Make Other Object Systems Envious
257 =item Makes Object Orientation So Easy
259 =item Makes Object Orientation Spiffy- Er (sorry ingy)
261 =item Most Other Object Systems Emasculate
263 =item My Overcraft Overfilled (with) Some Eels
265 =item Moose Often Ovulate Sorta Early
267 =item Many Overloaded Object Systems Exists
269 =item Moose Offers Often Super Extensions
271 =item Meta Object Orientation Syntax Extensions
275 =head1 BUILDING CLASSES WITH MOOSE
277 Moose makes every attempt to provide as much convience during class
278 construction/definition, but still stay out of your way if you want
279 it to. Here are some of the features Moose provides:
281 Unless specified with C<extends>, any class which uses Moose will
282 inherit from L<Moose::Object>.
284 Moose will also manage all attributes (including inherited ones) that
285 are defined with C<has>. And assuming that you call C<new> which is
286 inherited from L<Moose::Object>, then this includes properly initializing
287 all instance slots, setting defaults where approprtiate and performing any
288 type constraint checking or coercion.
290 For more details, see the ever expanding L<Moose::Cookbook>.
292 =head1 EXPORTED FUNCTIONS
294 Moose will export a number of functions into the class's namespace, which
295 can then be used to set up the class. These functions all work directly
296 on the current class.
302 This is a method which provides access to the current class's metaclass.
304 =item B<extends (@superclasses)>
306 This function will set the superclass(es) for the current class.
308 This approach is recommended instead of C<use base>, because C<use base>
309 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
310 replace it. This is important to ensure that classes which do not have
311 superclasses properly inherit from L<Moose::Object>.
313 =item B<with ($role)>
315 This will apply a given C<$role> to the local class. Role support is
316 currently very experimental, see L<Moose::Role> for more details.
318 =item B<has ($name, %options)>
320 This will install an attribute of a given C<$name> into the current class.
321 The list of C<%options> are the same as those provided by both
322 L<Class::MOP::Attribute> and L<Moose::Meta::Attribute>, in addition to a
323 few convience ones provided by Moose which are listed below:
327 =item I<is =E<gt> 'rw'|'ro'>
329 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
330 only). These will create either a read/write accessor or a read-only
331 accessor respectively, using the same name as the C<$name> of the attribute.
333 If you need more control over how your accessors are named, you can use the
334 I<reader>, I<writer> and I<accessor> options inherited from L<Moose::Meta::Attribute>.
336 =item I<isa =E<gt> $type_name>
338 The I<isa> option uses Moose's type constraint facilities to set up runtime
339 type checking for this attribute. Moose will perform the checks during class
340 construction, and within any accessors. The C<$type_name> argument must be a
341 string. The string can be either a class name, or a type defined using
342 Moose's type defintion features.
346 =item B<before $name|@names =E<gt> sub { ... }>
348 =item B<after $name|@names =E<gt> sub { ... }>
350 =item B<around $name|@names =E<gt> sub { ... }>
352 This three items are syntactic sugar for the before, after and around method
353 modifier features that L<Class::MOP> provides. More information on these can
354 be found in the L<Class::MOP> documentation for now.
358 The keyword C<super> is a noop when called outside of an C<override> method. In
359 the context of an C<override> method, it will call the next most appropriate
360 superclass method with the same arguments as the original method.
362 =item B<override ($name, &sub)>
364 An C<override> method, is a way of explictly saying "I am overriding this
365 method from my superclass". You can call C<super> within this method, and
366 it will work as expected. The same thing I<can> be accomplished with a normal
367 method call and the C<SUPER::> pseudo-package, it is really your choice.
371 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
372 an C<augment> method. You can think of C<inner> as being the inverse of
373 C<super>, the details of how C<inner> and C<augment> work is best described in
374 the L<Moose::Cookbook>.
376 =item B<augment ($name, &sub)>
378 An C<augment> method, is a way of explictly saying "I am augmenting this
379 method from my superclass". Once again, the details of how C<inner> and
380 C<augment> work is best described in the L<Moose::Cookbook>.
384 This is the C<Carp::confess> function, and exported here beause I use it
385 all the time. This feature may change in the future, so you have been warned.
389 This is the C<Scalar::Uti::blessed> function, it is exported here beause I
390 use it all the time. It is highly recommended that this is used instead of
391 C<ref> anywhere you need to test for an object's class name.
401 It should be noted that C<super> and C<inner> can B<not> be used in the same
402 method. However, they can be combined together with the same class hierarchy,
403 see F<t/014_override_augment_inner_super.t> for an example.
405 The reason that this is so is because C<super> is only valid within a method
406 with the C<override> modifier, and C<inner> will never be valid within an
407 C<override> method. In fact, C<augment> will skip over any C<override> methods
408 when searching for it's appropriate C<inner>.
410 This might seem like a restriction, but I am of the opinion that keeping these
411 two features seperate (but interoperable) actually makes them easy to use since
412 their behavior is then easier to predict. Time will tell if I am right or not.
416 =head1 ACKNOWLEDGEMENTS
420 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
422 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
424 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
425 and it certainly wouldn't have this name ;P
427 =item The basis of the TypeContraints module was Rob Kinyon's idea
428 originally, I just ran with it.
430 =item Thanks to mst & chansen and the whole #moose poose for all the
431 ideas/feature-requests/encouragement
439 =item L<Class::MOP> documentation
441 =item The #moose channel on irc.perl.org
443 =item L<http://forum2.org/moose/>
445 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
447 This paper (suggested by lbr on #moose) was what lead to the implementation
448 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
449 want to understand this feature, I suggest you read this.
455 All complex software has bugs lurking in it, and this module is no
456 exception. If you find a bug please either email me, or add the bug
461 Stevan Little E<lt>stevan@iinteractive.comE<gt>
463 =head1 COPYRIGHT AND LICENSE
465 Copyright 2006 by Infinity Interactive, Inc.
467 L<http://www.iinteractive.com>
469 This library is free software; you can redistribute it and/or modify
470 it under the same terms as Perl itself.