7 our $VERSION = '0.18_002';
9 use Scalar::Util 'blessed', 'reftype';
11 use Sub::Name 'subname';
12 use B 'svref_2object';
18 use Moose::Meta::Class;
19 use Moose::Meta::TypeConstraint;
20 use Moose::Meta::TypeCoercion;
21 use Moose::Meta::Attribute;
22 use Moose::Meta::Instance;
25 use Moose::Util::TypeConstraints;
33 # make a subtype for each Moose class
36 => where { $_->isa($class) }
37 => optimize_as { blessed($_[0]) && $_[0]->isa($class) }
38 unless find_type_constraint($class);
41 if ($class->can('meta')) {
43 # this is the case where the metaclass pragma
44 # was used before the 'use Moose' statement to
45 # override a specific class
46 $meta = $class->meta();
47 (blessed($meta) && $meta->isa('Moose::Meta::Class'))
48 || confess "You already have a &meta function, but it does not return a Moose::Meta::Class";
52 # this is broken currently, we actually need
53 # to allow the possiblity of an inherited
54 # meta, which will not be visible until the
55 # user 'extends' first. This needs to have
56 # more intelligence to it
57 $meta = Moose::Meta::Class->initialize($class);
58 $meta->add_method('meta' => sub {
59 # re-initialize so it inherits properly
60 Moose::Meta::Class->initialize(blessed($_[0]) || $_[0]);
64 # make sure they inherit from Moose::Object
65 $meta->superclasses('Moose::Object')
66 unless $meta->superclasses();
72 return subname 'Moose::extends' => sub (@) {
73 confess "Must derive at least one class" unless @_;
74 _load_all_classes(@_);
75 # this checks the metaclass to make sure
76 # it is correct, sometimes it can get out
77 # of sync when the classes are being built
78 my $meta = $class->meta->_fix_metaclass_incompatability(@_);
79 $meta->superclasses(@_);
84 return subname 'Moose::with' => sub (@) {
86 confess "Must specify at least one role" unless @roles;
87 _load_all_classes(@roles);
88 $class->meta->_apply_all_roles(@roles);
93 return subname 'Moose::has' => sub ($;%) {
94 my ($name, %options) = @_;
95 $class->meta->_process_attribute($name, %options);
100 return subname 'Moose::before' => sub (@&) {
102 my $meta = $class->meta;
103 $meta->add_before_method_modifier($_, $code) for @_;
108 return subname 'Moose::after' => sub (@&) {
110 my $meta = $class->meta;
111 $meta->add_after_method_modifier($_, $code) for @_;
116 return subname 'Moose::around' => sub (@&) {
118 my $meta = $class->meta;
119 $meta->add_around_method_modifier($_, $code) for @_;
123 return subname 'Moose::super' => sub {};
127 return subname 'Moose::override' => sub ($&) {
128 my ($name, $method) = @_;
129 $class->meta->add_override_method_modifier($name => $method);
133 return subname 'Moose::inner' => sub {};
137 return subname 'Moose::augment' => sub (@&) {
138 my ($name, $method) = @_;
139 $class->meta->add_augment_method_modifier($name => $method);
144 # this is experimental, but I am not
145 # happy with it. If you want to try
146 # it, you will have to uncomment it
148 # There is a really good chance that
149 # this will be deprecated, dont get
152 # return subname 'Moose::self' => sub {};
155 # my $class = $CALLER;
156 # return subname 'Moose::method' => sub {
157 # my ($name, $method) = @_;
158 # $class->meta->add_method($name, sub {
161 # no warnings 'redefine';
162 # local *{$class->meta->name . '::self'} = sub { $self };
169 return \&Carp::confess;
172 return \&Scalar::Util::blessed;
176 my $exporter = Sub::Exporter::build_exporter({
177 exports => \%exports,
189 # we should never export to main
190 return if $CALLER eq 'main';
199 my $class = caller();
200 # loop through the exports ...
201 foreach my $name (keys %exports) {
202 next if $name =~ /inner|super|self/;
205 if (defined &{$class . '::' . $name}) {
206 my $keyword = \&{$class . '::' . $name};
208 # make sure it is from Moose
209 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
211 next if $pkg_name ne 'Moose';
213 # and if it is from Moose then undef the slot
214 delete ${$class . '::'}{$name};
224 sub _load_all_classes {
225 foreach my $class (@_) {
226 # see if this is already
227 # loaded in the symbol table
228 next if _is_class_already_loaded($class);
229 # otherwise require it ...
230 my $file = $class . '.pm';
232 eval { CORE::require($file) };
234 "Could not load module '$class' because : $@"
239 sub _is_class_already_loaded {
242 return 1 if defined ${"${name}::VERSION"} || defined @{"${name}::ISA"};
243 foreach (keys %{"${name}::"}) {
244 next if substr($_, -2, 2) eq '::';
245 return 1 if defined &{"${name}::$_"};
250 ## make 'em all immutable
252 $_->meta->make_immutable(
253 inline_constructor => 0,
254 inline_accessors => 0,
256 'Moose::Meta::Attribute',
257 'Moose::Meta::Class',
258 'Moose::Meta::Instance',
260 'Moose::Meta::TypeConstraint',
261 'Moose::Meta::TypeConstraint::Union',
262 'Moose::Meta::TypeCoercion',
264 'Moose::Meta::Method',
265 'Moose::Meta::Method::Accessor',
266 'Moose::Meta::Method::Constructor',
267 'Moose::Meta::Method::Overriden',
278 Moose - A complete modern object system for Perl 5
287 has 'x' => (is => 'rw', isa => 'Int');
288 has 'y' => (is => 'rw', isa => 'Int');
303 has 'z' => (is => 'rw', isa => 'Int');
305 after 'clear' => sub {
312 Moose is a rapidly maturing module, and is already being used by
313 a number of people. It's test suite is growing larger by the day,
314 and the docs should soon follow.
316 This said, Moose is not yet finished, and should still be considered
317 to be evolving. Much of the outer API is stable, but the internals
318 are still subject to change (although not without serious thought
323 Moose is an extension of the Perl 5 object system.
325 =head2 Another object system!?!?
327 Yes, I know there has been an explosion recently of new ways to
328 build object's in Perl 5, most of them based on inside-out objects
329 and other such things. Moose is different because it is not a new
330 object system for Perl 5, but instead an extension of the existing
333 Moose is built on top of L<Class::MOP>, which is a metaclass system
334 for Perl 5. This means that Moose not only makes building normal
335 Perl 5 objects better, but it also provides the power of metaclass
338 =head2 Can I use this in production? Or is this just an experiment?
340 Moose is I<based> on the prototypes and experiments I did for the Perl 6
341 meta-model; however Moose is B<NOT> an experiment/prototype, it is
342 for B<real>. I will be deploying Moose into production environments later
343 this year, and I have every intentions of using it as my de facto class
346 =head2 Is Moose just Perl 6 in Perl 5?
348 No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
349 Instead, it is an OO system for Perl 5. I built Moose because I was tired or
350 writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
351 instead of switching to Ruby, I wrote Moose :)
353 =head1 BUILDING CLASSES WITH MOOSE
355 Moose makes every attempt to provide as much convenience as possible during
356 class construction/definition, but still stay out of your way if you want it
357 to. Here are a few items to note when building classes with Moose.
359 Unless specified with C<extends>, any class which uses Moose will
360 inherit from L<Moose::Object>.
362 Moose will also manage all attributes (including inherited ones) that
363 are defined with C<has>. And assuming that you call C<new>, which is
364 inherited from L<Moose::Object>, then this includes properly initializing
365 all instance slots, setting defaults where appropriate, and performing any
366 type constraint checking or coercion.
368 =head1 EXPORTED FUNCTIONS
370 Moose will export a number of functions into the class's namespace which
371 can then be used to set up the class. These functions all work directly
372 on the current class.
378 This is a method which provides access to the current class's metaclass.
380 =item B<extends (@superclasses)>
382 This function will set the superclass(es) for the current class.
384 This approach is recommended instead of C<use base>, because C<use base>
385 actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
386 replace it. This is important to ensure that classes which do not have
387 superclasses still properly inherit from L<Moose::Object>.
389 =item B<with (@roles)>
391 This will apply a given set of C<@roles> to the local class. Role support
392 is currently under heavy development; see L<Moose::Role> for more details.
394 =item B<has ($name, %options)>
396 This will install an attribute of a given C<$name> into the current class.
397 The list of C<%options> are the same as those provided by
398 L<Class::MOP::Attribute>, in addition to the list below which are provided
399 by Moose (L<Moose::Meta::Attribute> to be more specific):
403 =item I<is =E<gt> 'rw'|'ro'>
405 The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
406 only). These will create either a read/write accessor or a read-only
407 accessor respectively, using the same name as the C<$name> of the attribute.
409 If you need more control over how your accessors are named, you can use the
410 I<reader>, I<writer> and I<accessor> options inherited from L<Class::MOP::Attribute>.
412 =item I<isa =E<gt> $type_name>
414 The I<isa> option uses Moose's type constraint facilities to set up runtime
415 type checking for this attribute. Moose will perform the checks during class
416 construction, and within any accessors. The C<$type_name> argument must be a
417 string. The string can be either a class name or a type defined using
418 Moose's type definition features.
420 =item I<coerce =E<gt> (1|0)>
422 This will attempt to use coercion with the supplied type constraint to change
423 the value passed into any accessors or constructors. You B<must> have supplied
424 a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
425 for an example usage.
427 =item I<does =E<gt> $role_name>
429 This will accept the name of a role which the value stored in this attribute
430 is expected to have consumed.
432 =item I<required =E<gt> (1|0)>
434 This marks the attribute as being required. This means a value must be supplied
435 during class construction, and the attribute can never be set to C<undef> with
438 =item I<weak_ref =E<gt> (1|0)>
440 This will tell the class to store the value of this attribute as a weakened
441 reference. If an attribute is a weakened reference, it B<cannot> also be
444 =item I<lazy =E<gt> (1|0)>
446 This will tell the class to not create this slot until absolutely necessary.
447 If an attribute is marked as lazy it B<must> have a default supplied.
449 =item I<auto_deref =E<gt> (1|0)>
451 This tells the accessor whether to automatically dereference the value returned.
452 This is only legal if your C<isa> option is either an C<ArrayRef> or C<HashRef>.
454 =item I<trigger =E<gt> $code>
456 The trigger option is a CODE reference which will be called after the value of
457 the attribute is set. The CODE ref will be passed the instance itself, the
458 updated value and the attribute meta-object (this is for more advanced fiddling
459 and can typically be ignored in most cases). You B<cannot> have a trigger on
460 a read-only attribute.
462 =item I<handles =E<gt> [ @handles ]>
464 There is experimental support for attribute delegation using the C<handles>
465 option. More docs to come later.
469 =item B<before $name|@names =E<gt> sub { ... }>
471 =item B<after $name|@names =E<gt> sub { ... }>
473 =item B<around $name|@names =E<gt> sub { ... }>
475 This three items are syntactic sugar for the before, after, and around method
476 modifier features that L<Class::MOP> provides. More information on these can
477 be found in the L<Class::MOP> documentation for now.
481 The keyword C<super> is a no-op when called outside of an C<override> method. In
482 the context of an C<override> method, it will call the next most appropriate
483 superclass method with the same arguments as the original method.
485 =item B<override ($name, &sub)>
487 An C<override> method is a way of explicitly saying "I am overriding this
488 method from my superclass". You can call C<super> within this method, and
489 it will work as expected. The same thing I<can> be accomplished with a normal
490 method call and the C<SUPER::> pseudo-package; it is really your choice.
494 The keyword C<inner>, much like C<super>, is a no-op outside of the context of
495 an C<augment> method. You can think of C<inner> as being the inverse of
496 C<super>; the details of how C<inner> and C<augment> work is best described in
497 the L<Moose::Cookbook>.
499 =item B<augment ($name, &sub)>
501 An C<augment> method, is a way of explicitly saying "I am augmenting this
502 method from my superclass". Once again, the details of how C<inner> and
503 C<augment> work is best described in the L<Moose::Cookbook>.
507 This is the C<Carp::confess> function, and exported here because I use it
508 all the time. This feature may change in the future, so you have been warned.
512 This is the C<Scalar::Uti::blessed> function, it is exported here because I
513 use it all the time. It is highly recommended that this is used instead of
514 C<ref> anywhere you need to test for an object's class name.
518 =head1 UNEXPORTING FUNCTIONS
522 Moose offers a way of removing the keywords it exports though the C<unimport>
523 method. You simply have to say C<no Moose> at the bottom of your code for this
524 to work. Here is an example:
529 has 'first_name' => (is => 'rw', isa => 'Str');
530 has 'last_name' => (is => 'rw', isa => 'Str');
534 $self->first_name . ' ' . $self->last_name
537 no Moose; # keywords are removed from the Person package
541 =head2 What does Moose stand for??
543 Moose doesn't stand for one thing in particular, however, if you
544 want, here are a few of my favorites; feel free to contribute
549 =item Make Other Object Systems Envious
551 =item Makes Object Orientation So Easy
553 =item Makes Object Orientation Spiffy- Er (sorry ingy)
555 =item Most Other Object Systems Emasculate
557 =item Moose Often Ovulate Sorta Early
559 =item Moose Offers Often Super Extensions
561 =item Meta Object Orientation Syntax Extensions
571 It should be noted that C<super> and C<inner> C<cannot> be used in the same
572 method. However, they can be combined together with the same class hierarchy;
573 see F<t/014_override_augment_inner_super.t> for an example.
575 The reason for this is that C<super> is only valid within a method
576 with the C<override> modifier, and C<inner> will never be valid within an
577 C<override> method. In fact, C<augment> will skip over any C<override> methods
578 when searching for its appropriate C<inner>.
580 This might seem like a restriction, but I am of the opinion that keeping these
581 two features separate (but interoperable) actually makes them easy to use, since
582 their behavior is then easier to predict. Time will tell if I am right or not.
586 =head1 ACKNOWLEDGEMENTS
590 =item I blame Sam Vilain for introducing me to the insanity that is meta-models.
592 =item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
594 =item Without Yuval "nothingmuch" Kogman this module would not be possible,
595 and it certainly wouldn't have this name ;P
597 =item The basis of the TypeContraints module was Rob Kinyon's idea
598 originally, I just ran with it.
600 =item Thanks to mst & chansen and the whole #moose poose for all the
601 ideas/feature-requests/encouragement
603 =item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes.
611 =item L<Class::MOP> documentation
613 =item The #moose channel on irc.perl.org
615 =item The Moose mailing list - moose@perl.org
617 =item L<http://forum2.org/moose/>
619 =item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
621 This paper (suggested by lbr on #moose) was what lead to the implementation
622 of the C<super>/C<overrride> and C<inner>/C<augment> features. If you really
623 want to understand this feature, I suggest you read this.
629 All complex software has bugs lurking in it, and this module is no
630 exception. If you find a bug please either email me, or add the bug
635 Stevan Little E<lt>stevan@iinteractive.comE<gt>
637 Christian Hansen E<lt>chansen@cpan.orgE<gt>
639 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
641 =head1 COPYRIGHT AND LICENSE
643 Copyright 2006 by Infinity Interactive, Inc.
645 L<http://www.iinteractive.com>
647 This library is free software; you can redistribute it and/or modify
648 it under the same terms as Perl itself.