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 L<Moose::AttributeHelpers> has been moved into the Moose core from
22 L<MooseX::AttributeHelpers>. Major changes include:
26 =item C<traits>, not C<metaclass>
28 Method providers are only available via traits.
30 =item C<handles>, not C<provides> or C<curries>
32 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
33 syntax, but with the keys and values reversed. This was confusing,
34 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
35 should be intuitive to anyone already familiar with how it is used for
38 The C<curries> functionality provided by AttributeHelpers has been
39 generalized to apply to all cases of C<< handles => HASHREF >>, though
40 not every piece of functionality has been ported (currying with a
41 CODEREF is not supported).
45 See L<Moose::AttributeHelpers> for the new documentation.
49 When an attribute generates I<no> accessors, we now warn. This is to help
50 users who forget the C<is> option. If you really do not want any accessors,
51 you can use C<< is => 'bare' >>. You can maintain back compat with older
52 versions of Moose by using something like:
54 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
56 When an accessor overwrites an existing method, we now warn. To work around
57 this warning (if you really must have this behavior), you can explicitly
58 remove the method before creating it as an accessor:
62 __PACKAGE__->meta->remove_method('foo');
68 When an unknown option is passed to C<has>, we now warn. You can silence
69 the warning by fixing your code. :)
71 The C<Role> type has been deprecated. On its own, it was useless,
72 since it just checked C<< $object->can('does') >>. If you were using
73 it as a parent type, just call C<role_type('Role::Name')> to create an
74 appropriate type instead.
78 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
83 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
84 not we are in global destruction.
88 Type constraints no longer run coercions for a value that already matches the
89 constraint. This may affect some (arguably buggy) edge case coercions that
90 rely on side effects in the C<via> clause.
94 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
95 overriding the metaclass (without L<metaclass>). This works for classes
100 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
101 to make integration with non-Moose classes easier. It simply checks if
102 C<< $obj->can() >> a list of methods.
104 A number of methods (mostly inherited from L<Class::MOP>) have been
105 renamed with a leading underscore to indicate their internal-ness. The
106 old method names will still work for a while, but will warn that the
107 method has been renamed. In a few cases, the method will be removed
108 entirely in the future. This may affect MooseX authors who were using
113 Calling C<subtype> with a name as the only argument now throws an
114 exception. If you want an anonymous subtype do:
116 my $subtype = subtype as 'Foo';
118 This is related to the changes in version 0.71_01.
120 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
121 only usable as a class method. Previously, it worked as a class or
122 object method, with a different internal implementation for each
125 The internals of making a class immutable changed a lot in Class::MOP
126 0.78_02, and Moose's internals have changed along with it. The
127 external C<< $metaclass->make_immutable >> method still works the same
132 A mutable class accepted C<< Foo->new(undef) >> without complaint,
133 while an immutable class would blow up with an unhelpful error. Now,
134 in both cases we throw a helpful error instead.
136 This "feature" was originally added to allow for cases such as this:
144 return My::Class->new($args);
146 But we decided this is a bad idea and a little too magical, because it
147 can easily mask real errors.
149 =head1 Version 0.71_01
151 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
152 C<where>, C<message>) is now deprecated.
154 As a side effect, this meant we ended up using Perl prototypes on
155 C<as>, and code like this will no longer work:
157 use Moose::Util::TypeConstraints;
158 use Declare::Constraints::Simple -All;
160 subtype 'ArrayOfInts'
162 => IsArrayRef(IsInt);
164 Instead it must be changed to this:
169 where => IsArrayRef(IsInt)
173 If you want to maintain backwards compat with older versions of Moose,
174 you must explicitly test Moose's C<VERSION>:
176 if ( Moose->VERSION < 0.71_01 ) {
177 subtype 'ArrayOfInts'
179 => IsArrayRef(IsInt);
185 where => IsArrayRef(IsInt)
192 We no longer pass the meta-attribute object as a final argument to
193 triggers. This actually changed for inlined code a while back, but the
194 non-inlined version and the docs were still out of date.
196 If by some chance you actually used this feature, the workaround is
197 simple. You fetch the attribute object from out of the C<$self>
198 that is passed as the first argument to trigger, like so:
204 my ( $self, $value ) = @_;
205 my $attr = $self->meta->find_attribute_by_name('foo');
213 If you created a subtype and passed a parent that Moose didn't know
214 about, it simply ignored the parent. Now it automatically creates the
215 parent as a class type. This may not be what you want, but is less
218 You could declare a name with subtype such as "Foo!Bar". Moose would
219 accept this allowed, but if you used it in a parameterized type such
220 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
221 names created via the sugar functions, so that they can only contain
222 alphanumerics, ":", and ".".
226 Methods created via an attribute can now fulfill a C<requires>
227 declaration for a role. Honestly we don't know why Stevan didn't make
228 this work originally, he was just insane or something.
230 Stack traces from inlined code will now report the line and file as
231 being in your class, as opposed to in Moose guts.
233 =head1 Version 0.62_02
235 When a class does not provide all of a role's required methods, the
236 error thrown now mentions all of the missing methods, as opposed to
237 just the first missing method.
239 Moose will no longer inline a constructor for your class unless it
240 inherits its constructor from Moose::Object, and will warn when it
241 doesn't inline. If you want to force inlining anyway, pass
242 C<< replace_constructor => 1 >> to C<make_immutable>.
244 If you want to get rid of the warning, pass C<< inline_constructor =>
249 Removed the (deprecated) C<make_immutable> keyword.
251 Removing an attribute from a class now also removes delegation
252 (C<handles>) methods installed for that attribute. This is correct
253 behavior, but if you were wrongly relying on it you might get bit.
257 Roles now add methods by calling C<add_method>, not
258 C<alias_method>. They make sure to always provide a method object,
259 which will be cloned internally. This means that it is now possible to
260 track the source of a method provided by a role, and even follow its
261 history through intermediate roles. This means that methods added by
262 a role now show up when looking at a class's method list/map.
264 Parameter and Union args are now sorted, this makes Int|Str the same
265 constraint as Str|Int. Also, incoming type constraint strings are
266 normalized to remove all whitespace differences. This is mostly for
267 internals and should not affect outside code.
269 L<Moose::Exporter> will no longer remove a subroutine that the
270 exporting package re-exports. Moose re-exports the Carp::confess
271 function, among others. The reasoning is that we cannot know whether
272 you have also explicitly imported those functions for your own use, so
273 we err on the safe side and always keep them.
277 C<Moose::init_meta> should now be called as a method.
279 New modules for extension writers, L<Moose::Exporter> and
280 L<Moose::Util::MetaRole>.
282 =head1 Version 0.55_01
284 Implemented metaclass traits (and wrote a recipe for it):
286 use Moose -traits => 'Foo'
288 This should make writing small Moose extensions a little
293 Fixed C<coerce> to accept anon types just like C<subtype> can.
296 coerce $some_anon_type => from 'Str' => via { ... };
300 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
304 Fixed how the C<< is => (ro|rw) >> works with custom defined
305 C<reader>, C<writer> and C<accessor> options. See the below table for
308 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
309 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
310 is => rw, accessor => _foo # turns into (accessor => _foo)
311 is => ro, accessor => _foo # error, accesor is rw
315 The C<before/around/after> method modifiers now support regexp
316 matching of method names. NOTE: this only works for classes, it is
317 currently not supported in roles, but, ... patches welcome.
319 The C<has> keyword for roles now accepts the same array ref form that
320 L<Moose>.pm does for classes.
322 A trigger on a read-only attribute is no longer an error, as it's
323 useful to trigger off of the constructor.
325 Subtypes of parameterizable types now are parameterizable types
330 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
331 not working correctly. It still kind of eats them, but so does vanilla
336 Inherited attributes may now be extended without restriction on the
337 type ('isa', 'does').
339 The entire set of Moose::Meta::TypeConstraint::* classes were
340 refactored in this release. If you were relying on their internals you
341 should test your code carefully.
345 Documenting the use of '+name' with attributes that come from recently
346 composed roles. It makes sense, people are using it, and so why not
347 just officially support it.
349 The C<< Moose::Meta::Class->create >> method now supports roles.
351 It is now possible to make anonymous enum types by passing C<enum> an
352 array reference instead of the C<< enum $name => @values >>.
356 Added the C<make_immutable> keyword as a shortcut to calling
357 C<make_immutable> on the meta object. This eventually got removed!
359 Made C<< init_arg => undef >> work in Moose. This means "do not accept
360 a constructor parameter for this attribute".
362 Type errors now use the provided message. Prior to this release they
367 Moose is now a postmodern object system :)
369 The Role system was completely refactored. It is 100% backwards
370 compat, but the internals were totally changed. If you relied on the
371 internals then you are advised to test carefully.
373 Added method exclusion and aliasing for Roles in this release.
375 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
378 Passing a list of values to an accessor (which is only expecting one
379 value) used to be silently ignored, now it throws an error.
383 Added parameterized types and did a pretty heavy refactoring of the
384 type constraint system.
386 Better framework extendability and better support for "making your own
389 =head1 Version 0.25 or before
391 Honestly, you shouldn't be using versions of Moose that are this old,
392 so many bug fixes and speed improvements have been made you would be
393 crazy to not upgrade.
395 Also, I am tired of going through the Changelog so I am stopping here,
396 if anyone would like to continue this please feel free.
400 Stevan Little E<lt>stevan@iinteractive.comE<gt>
402 =head1 COPYRIGHT AND LICENSE
404 Copyright 2009 by Infinity Interactive, Inc.
406 L<http://www.iinteractive.com>
408 This library is free software; you can redistribute it and/or modify
409 it under the same terms as Perl itself.