10 if ($ENV{MOUSE_DEBUG}) {
18 use Scalar::Util 'blessed';
21 use Mouse::Meta::Attribute;
22 use Mouse::Meta::Class;
24 use Mouse::Util::TypeConstraints;
26 our @EXPORT = qw(extends has before after around override super blessed confess with);
28 sub extends { Mouse::Meta::Class->initialize(caller)->superclasses(@_) }
31 my $meta = Mouse::Meta::Class->initialize(caller);
34 $names = [$names] if !ref($names);
35 my $metaclass = 'Mouse::Meta::Attribute';
38 if ( my $metaclass_name = delete $options{metaclass} ) {
39 my $new_class = Mouse::Util::resolve_metaclass_alias(
43 if ( $metaclass ne $new_class ) {
44 $metaclass = $new_class;
48 for my $name (@$names) {
49 if ($name =~ s/^\+//) {
50 $metaclass->clone_parent($meta, $name, @_);
53 $metaclass->create($meta, $name, @_);
59 my $meta = Mouse::Meta::Class->initialize(caller);
64 $meta->add_before_method_modifier($_ => $code);
69 my $meta = Mouse::Meta::Class->initialize(caller);
74 $meta->add_after_method_modifier($_ => $code);
79 my $meta = Mouse::Meta::Class->initialize(caller);
84 $meta->add_around_method_modifier($_ => $code);
89 Mouse::Util::apply_all_roles((caller)[0], @_);
97 # This check avoids a recursion loop - see
98 # t/100_bugs/020_super_recursion.t
99 return if defined $SUPER_PACKAGE && $SUPER_PACKAGE ne caller();
100 return unless $SUPER_BODY; $SUPER_BODY->(@SUPER_ARGS);
104 my $meta = Mouse::Meta::Class->initialize(caller);
105 my $pkg = $meta->name;
110 my $body = $pkg->can($name)
111 or confess "You cannot override '$name' because it has no super method";
113 $meta->add_method($name => sub {
114 local $SUPER_PACKAGE = $pkg;
115 local @SUPER_ARGS = @_;
116 local $SUPER_BODY = $body;
129 if (ref($_[0]) && ref($_[0]) eq 'HASH') {
135 my $level = delete $opts->{into_level};
136 $level = 0 unless defined $level;
137 my $caller = caller($level);
139 # we should never export to main
140 if ($caller eq 'main') {
141 warn qq{$class does not export its sugar to the 'main' package.\n};
145 my $meta = Mouse::Meta::Class->initialize($caller);
146 $meta->superclasses('Mouse::Object')
147 unless $meta->superclasses;
150 no warnings 'redefine';
151 *{$caller.'::meta'} = sub { $meta };
154 __PACKAGE__->export_to_level( $level+1, $class, @_);
156 # shortcut for the common case of no type character
158 for my $keyword (@EXPORT) {
159 *{ $caller . '::' . $keyword } = *{__PACKAGE__ . '::' . $keyword};
168 for my $keyword (@EXPORT) {
169 delete ${ $caller . '::' }{$keyword};
176 if (ref($class) || !defined($class) || !length($class)) {
177 my $display = defined($class) ? $class : 'undef';
178 confess "Invalid class name ($display)";
181 return 1 if $class eq 'Mouse::Object';
182 return 1 if is_class_loaded($class);
184 (my $file = "$class.pm") =~ s{::}{/}g;
186 eval { CORE::require($file) };
187 confess "Could not load class ($class) because : $@" if $@;
192 sub is_class_loaded {
195 return 0 if ref($class) || !defined($class) || !length($class);
197 # walk the symbol table tree to avoid autovififying
198 # \*{${main::}{"Foo::"}} == \*main::Foo::
201 foreach my $part (split('::', $class)) {
202 return 0 unless exists ${$$pack}{"${part}::"};
203 $pack = \*{${$$pack}{"${part}::"}};
206 # check for $VERSION or @ISA
207 return 1 if exists ${$$pack}{VERSION}
208 && defined *{${$$pack}{VERSION}}{SCALAR};
209 return 1 if exists ${$$pack}{ISA}
210 && defined *{${$$pack}{ISA}}{ARRAY};
212 # check for any method
213 foreach ( keys %{$$pack} ) {
214 next if substr($_, -2, 2) eq '::';
215 return 1 if defined *{${$$pack}{$_}}{CODE};
228 Mouse - Moose minus the antlers
233 use Mouse; # automatically turns on strict and warnings
235 has 'x' => (is => 'rw', isa => 'Int');
236 has 'y' => (is => 'rw', isa => 'Int');
249 has 'z' => (is => 'rw', isa => 'Int');
251 after 'clear' => sub {
258 L<Moose> is wonderful.
260 Unfortunately, it's a little slow. Though significant progress has been made
261 over the years, the compile time penalty is a non-starter for some
264 Mouse aims to alleviate this by providing a subset of Moose's
265 functionality, faster. In particular, L<Moose/has> is missing only a few
266 expert-level features.
268 We're also going as light on dependencies as possible.
269 L<Class::Method::Modifiers> or L<Data::Util> is required if you want support
270 for L</before>, L</after>, and L</around>.
274 Compatibility with Moose has been the utmost concern. Fewer than 1% of the
275 tests fail when run against Moose instead of Mouse. Mouse code coverage is also
276 over 96%. Even the error messages are taken from Moose. The Mouse code just
277 runs the test suite 4x faster.
279 The idea is that, if you need the extra power, you should be able to run
280 C<s/Mouse/Moose/g> on your codebase and have nothing break. To that end,
281 nothingmuch has written L<Squirrel> (part of this distribution) which will act
282 as Mouse unless Moose is loaded, in which case it will act as Moose.
283 L<Any::Moose> is a more high-tech L<Squirrel>.
287 Please don't copy MooseX code to MouseX. If you need extensions, you really
288 should upgrade to Moose. We don't need two parallel sets of extensions!
290 If you really must write a Mouse extension, please contact the Moose mailing
291 list or #moose on IRC beforehand.
295 =head2 meta -> Mouse::Meta::Class
297 Returns this class' metaclass instance.
299 =head2 extends superclasses
301 Sets this class' superclasses.
303 =head2 before (method|methods) => Code
305 Installs a "before" method modifier. See L<Moose/before> or
306 L<Class::Method::Modifiers/before>.
308 Use of this feature requires L<Class::Method::Modifiers>!
310 =head2 after (method|methods) => Code
312 Installs an "after" method modifier. See L<Moose/after> or
313 L<Class::Method::Modifiers/after>.
315 Use of this feature requires L<Class::Method::Modifiers>!
317 =head2 around (method|methods) => Code
319 Installs an "around" method modifier. See L<Moose/around> or
320 L<Class::Method::Modifiers/around>.
322 Use of this feature requires L<Class::Method::Modifiers>!
324 =head2 has (name|names) => parameters
326 Adds an attribute (or if passed an arrayref of names, multiple attributes) to
333 If specified, inlines a read-only/read-write accessor with the same name as
336 =item isa => TypeConstraint
338 Provides basic type checking in the constructor and accessor. Basic types such
339 as C<Int>, C<ArrayRef>, C<Defined> are supported. Any unknown type is taken to
340 be a class check (e.g. isa => 'DateTime' would accept only L<DateTime>
343 =item required => 0|1
345 Whether this attribute is required to have a value. If the attribute is lazy or
346 has a builder, then providing a value for the attribute in the constructor is
349 =item init_arg => Str | Undef
351 Allows you to use a different key name in the constructor. If undef, the
352 attribue can't be passed to the constructor.
354 =item default => Value | CodeRef
356 Sets the default value of the attribute. If the default is a coderef, it will
357 be invoked to get the default value. Due to quirks of Perl, any bare reference
358 is forbidden, you must wrap the reference in a coderef. Otherwise, all
359 instances will share the same reference.
363 If specified, the default is calculated on demand instead of in the
366 =item predicate => Str
368 Lets you specify a method name for installing a predicate method, which checks
369 that the attribute has a value. It will not invoke a lazy default or builder
374 Lets you specify a method name for installing a clearer method, which clears
375 the attribute's value from the instance. On the next read, lazy or builder will
378 =item handles => HashRef|ArrayRef
380 Lets you specify methods to delegate to the attribute. ArrayRef forwards the
381 given method names to method calls on the attribute. HashRef maps local method
382 names to remote method names called on the attribute. Other forms of
383 L</handles>, such as regular expression and coderef, are not yet supported.
385 =item weak_ref => 0|1
387 Lets you automatically weaken any reference stored in the attribute.
389 Use of this feature requires L<Scalar::Util>!
391 =item trigger => CodeRef
393 Any time the attribute's value is set (either through the accessor or the constructor), the trigger is called on it. The trigger receives as arguments the instance, the new value, and the attribute instance.
395 Mouse 0.05 supported more complex triggers, but this behavior is now removed.
399 Defines a method name to be called to provide the default value of the
400 attribute. C<< builder => 'build_foo' >> is mostly equivalent to
401 C<< default => sub { $_[0]->build_foo } >>.
403 =item auto_deref => 0|1
405 Allows you to automatically dereference ArrayRef and HashRef attributes in list
406 context. In scalar context, the reference is returned (NOT the list length or
407 bucket status). You must specify an appropriate type constraint to use
410 =item lazy_build => 0|1
412 Automatically define lazy => 1 as well as builder => "_build_$attr", clearer =>
413 "clear_$attr', predicate => 'has_$attr' unless they are already defined.
417 =head2 confess error -> BOOM
419 L<Carp/confess> for your convenience.
421 =head2 blessed value -> ClassName | undef
423 L<Scalar::Util/blessed> for your convenience.
429 Importing Mouse will default your class' superclass list to L<Mouse::Object>.
430 You may use L</extends> to replace the superclass list.
434 Please unimport Mouse (C<no Mouse>) so that if someone calls one of the
435 keywords (such as L</extends>) it will break loudly instead breaking subtly.
439 =head2 load_class Class::Name
441 This will load a given C<Class::Name> (or die if it's not loadable).
442 This function can be used in place of tricks like
443 C<eval "use $module"> or using C<require>.
445 =head2 is_class_loaded Class::Name -> Bool
447 Returns whether this class is actually loaded or not. It uses a heuristic which
448 involves checking for the existence of C<$VERSION>, C<@ISA>, and any
449 locally-defined method.
453 Shawn M Moore, C<< <sartak at gmail.com> >>
455 Yuval Kogman, C<< <nothingmuch at woobling.org> >>
461 with plenty of code borrowed from L<Class::MOP> and L<Moose>
467 Please report any bugs through RT: email
468 C<bug-mouse at rt.cpan.org>, or browse
469 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mouse>.
471 =head1 COPYRIGHT AND LICENSE
473 Copyright 2008 Shawn M Moore.
475 This program is free software; you can redistribute it and/or modify it
476 under the same terms as Perl itself.