5 Moose::Manual::Delta - Important Changes in Moose
9 This documents any important or noteworthy changes in Moose, with a
10 focus on backwards. This does duplicate data from the F<Changes> file,
11 but aims to provide more details and when possible workarounds.
13 Besides helping keep up with changes, you can also use this document
14 for finding the lowest version of Moose that supported a given
15 feature. If you encounter a problem and have a solution but don't see
16 it documented here, or think we missed an important feature, please
21 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
22 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
24 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
25 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
26 a wrapper around the old
28 package Moose::Meta::Class::Custom::Trait::FooTrait;
29 sub register_implementation { 'My::Meta::Trait' }
35 When an attribute generates I<no> accessors, we now warn. This is to help
36 users who forget the C<is> option. If you really do not want any accessors,
37 you can use C<< is => 'bare' >>. You can maintain back compat with older
38 versions of Moose by using something like:
40 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
42 When an accessor overwrites an existing method, we now warn. To work around
43 this warning (if you really must have this behavior), you can explicitly
44 remove the method before creating it as an accessor:
48 __PACKAGE__->meta->remove_method('foo');
54 When an unknown option is passed to C<has>, we now warn. You can silence
55 the warning by fixing your code. :)
57 The C<Role> type has been deprecated. On its own, it was useless,
58 since it just checked C<< $object->can('does') >>. If you were using
59 it as a parent type, just call C<role_type('Role::Name')> to create an
60 appropriate type instead.
64 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
69 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
70 not we are in global destruction.
74 Type constraints no longer run coercions for a value that already matches the
75 constraint. This may affect some (arguably buggy) edge case coercions that
76 rely on side effects in the C<via> clause.
80 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
81 overriding the metaclass (without L<metaclass>). This works for classes
86 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
87 to make integration with non-Moose classes easier. It simply checks if
88 C<< $obj->can() >> a list of methods.
90 A number of methods (mostly inherited from L<Class::MOP>) have been
91 renamed with a leading underscore to indicate their internal-ness. The
92 old method names will still work for a while, but will warn that the
93 method has been renamed. In a few cases, the method will be removed
94 entirely in the future. This may affect MooseX authors who were using
99 Calling C<subtype> with a name as the only argument now throws an
100 exception. If you want an anonymous subtype do:
102 my $subtype = subtype as 'Foo';
104 This is related to the changes in version 0.71_01.
106 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
107 only usable as a class method. Previously, it worked as a class or
108 object method, with a different internal implementation for each
111 The internals of making a class immutable changed a lot in Class::MOP
112 0.78_02, and Moose's internals have changed along with it. The
113 external C<< $metaclass->make_immutable >> method still works the same
118 A mutable class accepted C<< Foo->new(undef) >> without complaint,
119 while an immutable class would blow up with an unhelpful error. Now,
120 in both cases we throw a helpful error instead.
122 This "feature" was originally added to allow for cases such as this:
130 return My::Class->new($args);
132 But we decided this is a bad idea and a little too magical, because it
133 can easily mask real errors.
135 =head1 Version 0.71_01
137 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
138 C<where>, C<message>) is now deprecated.
140 As a side effect, this meant we ended up using Perl prototypes on
141 C<as>, and code like this will no longer work:
143 use Moose::Util::TypeConstraints;
144 use Declare::Constraints::Simple -All;
146 subtype 'ArrayOfInts'
148 => IsArrayRef(IsInt);
150 Instead it must be changed to this:
155 where => IsArrayRef(IsInt)
159 If you want to maintain backwards compat with older versions of Moose,
160 you must explicitly test Moose's C<VERSION>:
162 if ( Moose->VERSION < 0.71_01 ) {
163 subtype 'ArrayOfInts'
165 => IsArrayRef(IsInt);
171 where => IsArrayRef(IsInt)
178 We no longer pass the meta-attribute object as a final argument to
179 triggers. This actually changed for inlined code a while back, but the
180 non-inlined version and the docs were still out of date.
182 If by some chance you actually used this feature, the workaround is
183 simple. You fetch the attribute object from out of the C<$self>
184 that is passed as the first argument to trigger, like so:
190 my ( $self, $value ) = @_;
191 my $attr = $self->meta->find_attribute_by_name('foo');
199 If you created a subtype and passed a parent that Moose didn't know
200 about, it simply ignored the parent. Now it automatically creates the
201 parent as a class type. This may not be what you want, but is less
204 You could declare a name with subtype such as "Foo!Bar". Moose would
205 accept this allowed, but if you used it in a parameterized type such
206 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
207 names created via the sugar functions, so that they can only contain
208 alphanumerics, ":", and ".".
212 Methods created via an attribute can now fulfill a C<requires>
213 declaration for a role. Honestly we don't know why Stevan didn't make
214 this work originally, he was just insane or something.
216 Stack traces from inlined code will now report the line and file as
217 being in your class, as opposed to in Moose guts.
219 =head1 Version 0.62_02
221 When a class does not provide all of a role's required methods, the
222 error thrown now mentions all of the missing methods, as opposed to
223 just the first missing method.
225 Moose will no longer inline a constructor for your class unless it
226 inherits its constructor from Moose::Object, and will warn when it
227 doesn't inline. If you want to force inlining anyway, pass
228 C<< replace_constructor => 1 >> to C<make_immutable>.
230 If you want to get rid of the warning, pass C<< inline_constructor =>
235 Removed the (deprecated) C<make_immutable> keyword.
237 Removing an attribute from a class now also removes delegation
238 (C<handles>) methods installed for that attribute. This is correct
239 behavior, but if you were wrongly relying on it you might get bit.
243 Roles now add methods by calling C<add_method>, not
244 C<alias_method>. They make sure to always provide a method object,
245 which will be cloned internally. This means that it is now possible to
246 track the source of a method provided by a role, and even follow its
247 history through intermediate roles. This means that methods added by
248 a role now show up when looking at a class's method list/map.
250 Parameter and Union args are now sorted, this makes Int|Str the same
251 constraint as Str|Int. Also, incoming type constraint strings are
252 normalized to remove all whitespace differences. This is mostly for
253 internals and should not affect outside code.
255 L<Moose::Exporter> will no longer remove a subroutine that the
256 exporting package re-exports. Moose re-exports the Carp::confess
257 function, among others. The reasoning is that we cannot know whether
258 you have also explicitly imported those functions for your own use, so
259 we err on the safe side and always keep them.
263 C<Moose::init_meta> should now be called as a method.
265 New modules for extension writers, L<Moose::Exporter> and
266 L<Moose::Util::MetaRole>.
268 =head1 Version 0.55_01
270 Implemented metaclass traits (and wrote a recipe for it):
272 use Moose -traits => 'Foo'
274 This should make writing small Moose extensions a little
279 Fixed C<coerce> to accept anon types just like C<subtype> can.
282 coerce $some_anon_type => from 'Str' => via { ... };
286 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
290 Fixed how the C<< is => (ro|rw) >> works with custom defined
291 C<reader>, C<writer> and C<accessor> options. See the below table for
294 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
295 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
296 is => rw, accessor => _foo # turns into (accessor => _foo)
297 is => ro, accessor => _foo # error, accesor is rw
301 The C<before/around/after> method modifiers now support regexp
302 matching of method names. NOTE: this only works for classes, it is
303 currently not supported in roles, but, ... patches welcome.
305 The C<has> keyword for roles now accepts the same array ref form that
306 L<Moose>.pm does for classes.
308 A trigger on a read-only attribute is no longer an error, as it's
309 useful to trigger off of the constructor.
311 Subtypes of parameterizable types now are parameterizable types
316 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
317 not working correctly. It still kind of eats them, but so does vanilla
322 Inherited attributes may now be extended without restriction on the
323 type ('isa', 'does').
325 The entire set of Moose::Meta::TypeConstraint::* classes were
326 refactored in this release. If you were relying on their internals you
327 should test your code carefully.
331 Documenting the use of '+name' with attributes that come from recently
332 composed roles. It makes sense, people are using it, and so why not
333 just officially support it.
335 The C<< Moose::Meta::Class->create >> method now supports roles.
337 It is now possible to make anonymous enum types by passing C<enum> an
338 array reference instead of the C<< enum $name => @values >>.
342 Added the C<make_immutable> keyword as a shortcut to calling
343 C<make_immutable> on the meta object. This eventually got removed!
345 Made C<< init_arg => undef >> work in Moose. This means "do not accept
346 a constructor parameter for this attribute".
348 Type errors now use the provided message. Prior to this release they
353 Moose is now a postmodern object system :)
355 The Role system was completely refactored. It is 100% backwards
356 compat, but the internals were totally changed. If you relied on the
357 internals then you are advised to test carefully.
359 Added method exclusion and aliasing for Roles in this release.
361 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
364 Passing a list of values to an accessor (which is only expecting one
365 value) used to be silently ignored, now it throws an error.
369 Added parameterized types and did a pretty heavy refactoring of the
370 type constraint system.
372 Better framework extendability and better support for "making your own
375 =head1 Version 0.25 or before
377 Honestly, you shouldn't be using versions of Moose that are this old,
378 so many bug fixes and speed improvements have been made you would be
379 crazy to not upgrade.
381 Also, I am tired of going through the Changelog so I am stopping here,
382 if anyone would like to continue this please feel free.
386 Stevan Little E<lt>stevan@iinteractive.comE<gt>
388 =head1 COPYRIGHT AND LICENSE
390 Copyright 2009 by Infinity Interactive, Inc.
392 L<http://www.iinteractive.com>
394 This library is free software; you can redistribute it and/or modify
395 it under the same terms as Perl itself.