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 The C<Role> type has been deprecated. On its own, it was useless,
50 since it just checked C<< $object->can('does') >>. If you were using
51 it as a parent type, just call C<role_type('Role::Name')> to create an
52 appropriate type instead.
56 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
61 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
62 not we are in global destruction.
66 Type constraints no longer run coercions for a value that already matches the
67 constraint. This may affect some (arguably buggy) edge case coercions that
68 rely on side effects in the C<via> clause.
72 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
73 overriding the metaclass (without L<metaclass>). This works for classes
78 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
79 to make integration with non-Moose classes easier. It simply checks if
80 C<< $obj->can() >> a list of methods.
82 A number of methods (mostly inherited from L<Class::MOP>) have been
83 renamed with a leading underscore to indicate their internal-ness. The
84 old method names will still work for a while, but will warn that the
85 method has been renamed. In a few cases, the method will be removed
86 entirely in the future. This may affect MooseX authors who were using
91 Calling C<subtype> with a name as the only argument now throws an
92 exception. If you want an anonymous subtype do:
94 my $subtype = subtype as 'Foo';
96 This is related to the changes in version 0.71_01.
98 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
99 only usable as a class method. Previously, it worked as a class or
100 object method, with a different internal implementation for each
103 The internals of making a class immutable changed a lot in Class::MOP
104 0.78_02, and Moose's internals have changed along with it. The
105 external C<< $metaclass->make_immutable >> method still works the same
110 A mutable class accepted C<< Foo->new(undef) >> without complaint,
111 while an immutable class would blow up with an unhelpful error. Now,
112 in both cases we throw a helpful error instead.
114 This "feature" was originally added to allow for cases such as this:
122 return My::Class->new($args);
124 But we decided this is a bad idea and a little too magical, because it
125 can easily mask real errors.
127 =head1 Version 0.71_01
129 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
130 C<where>, C<message>) is now deprecated.
132 As a side effect, this meant we ended up using Perl prototypes on
133 C<as>, and code like this will no longer work:
135 use Moose::Util::TypeConstraints;
136 use Declare::Constraints::Simple -All;
138 subtype 'ArrayOfInts'
140 => IsArrayRef(IsInt);
142 Instead it must be changed to this:
147 where => IsArrayRef(IsInt)
151 If you want to maintain backwards compat with older versions of Moose,
152 you must explicitly test Moose's C<VERSION>:
154 if ( Moose->VERSION < 0.71_01 ) {
155 subtype 'ArrayOfInts'
157 => IsArrayRef(IsInt);
163 where => IsArrayRef(IsInt)
170 We no longer pass the meta-attribute object as a final argument to
171 triggers. This actually changed for inlined code a while back, but the
172 non-inlined version and the docs were still out of date.
174 If by some chance you actually used this feature, the workaround is
175 simple. You fetch the attribute object from out of the C<$self>
176 that is passed as the first argument to trigger, like so:
182 my ( $self, $value ) = @_;
183 my $attr = $self->meta->find_attribute_by_name('foo');
191 If you created a subtype and passed a parent that Moose didn't know
192 about, it simply ignored the parent. Now it automatically creates the
193 parent as a class type. This may not be what you want, but is less
196 You could declare a name with subtype such as "Foo!Bar". Moose would
197 accept this allowed, but if you used it in a parameterized type such
198 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
199 names created via the sugar functions, so that they can only contain
200 alphanumerics, ":", and ".".
204 Methods created via an attribute can now fulfill a C<requires>
205 declaration for a role. Honestly we don't know why Stevan didn't make
206 this work originally, he was just insane or something.
208 Stack traces from inlined code will now report the line and file as
209 being in your class, as opposed to in Moose guts.
211 =head1 Version 0.62_02
213 When a class does not provide all of a role's required methods, the
214 error thrown now mentions all of the missing methods, as opposed to
215 just the first missing method.
217 Moose will no longer inline a constructor for your class unless it
218 inherits its constructor from Moose::Object, and will warn when it
219 doesn't inline. If you want to force inlining anyway, pass
220 C<< "replace_constructor => 1 >> to C<make_immutable>.
222 If you want to get rid of the warning, pass C<< inline_constructor =>
227 Removed the (deprecated) C<make_immutable> keyword.
229 Removing an attribute from a class now also removes delegation
230 (C<handles>) methods installed for that attribute. This is correct
231 behavior, but if you were wrongly relying on it you might get bit.
235 Roles now add methods by calling C<add_method>, not
236 C<alias_method>. They make sure to always provide a method object,
237 which will be cloned internally. This means that it is now possible to
238 track the source of a method provided by a role, and even follow its
239 history through intermediate roles. This means that methods added by
240 a role now show up when looking at a class's method list/map.
242 Parameter and Union args are now sorted, this makes Int|Str the same
243 constraint as Str|Int. Also, incoming type constraint strings are
244 normalized to remove all whitespace differences. This is mostly for
245 internals and should not affect outside code.
247 L<Moose::Exporter> will no longer remove a subroutine that the
248 exporting package re-exports. Moose re-exports the Carp::confess
249 function, among others. The reasoning is that we cannot know whether
250 you have also explicitly imported those functions for your own use, so
251 we err on the safe side and always keep them.
255 C<Moose::init_meta> should now be called as a method.
257 New modules for extension writers, L<Moose::Exporter> and
258 L<Moose::Util::MetaRole>.
260 =head1 Version 0.55_01
262 Implemented metaclass traits (and wrote a recipe for it):
264 use Moose -traits => 'Foo'
266 This should make writing small Moose extensions a little
271 Fixed C<coerce> to accept anon types just like C<subtype> can.
274 coerce $some_anon_type => from 'Str' => via { ... };
278 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
282 Fixed how the C<< is => (ro|rw) >> works with custom defined
283 C<reader>, C<writer> and C<accessor> options. See the below table for
286 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
287 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
288 is => rw, accessor => _foo # turns into (accessor => _foo)
289 is => ro, accessor => _foo # error, accesor is rw
293 The C<before/around/after> method modifiers now support regexp
294 matching of method names. NOTE: this only works for classes, it is
295 currently not supported in roles, but, ... patches welcome.
297 The C<has> keyword for roles now accepts the same array ref form that
298 L<Moose>.pm does for classes.
300 A trigger on a read-only attribute is no longer an error, as it's
301 useful to trigger off of the constructor.
303 Subtypes of parameterizable types now are parameterizable types
308 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
309 not working correctly. It still kind of eats them, but so does vanilla
314 Inherited attributes may now be extended without restriction on the
315 type ('isa', 'does').
317 The entire set of Moose::Meta::TypeConstraint::* classes were
318 refactored in this release. If you were relying on their internals you
319 should test your code carefully.
323 Documenting the use of '+name' with attributes that come from recently
324 composed roles. It makes sense, people are using it, and so why not
325 just officially support it.
327 The C<< Moose::Meta::Class->create >> method now supports roles.
329 It is now possible to make anonymous enum types by passing C<enum> an
330 array reference instead of the C<< enum $name => @values >>.
334 Added the C<make_immutable> keyword as a shortcut to calling
335 C<make_immutable> on the meta object. This eventually got removed!
337 Made C<< init_arg => undef >> work in Moose. This means "do not accept
338 a constructor parameter for this attribute".
340 Type errors now use the provided message. Prior to this release they
345 Moose is now a postmodern object system :)
347 The Role system was completely refactored. It is 100% backwards
348 compat, but the internals were totally changed. If you relied on the
349 internals then you are advised to test carefully.
351 Added method exclusion and aliasing for Roles in this release.
353 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
356 Passing a list of values to an accessor (which is only expecting one
357 value) used to be silently ignored, now it throws an error.
361 Added parameterized types and did a pretty heavy refactoring of the
362 type constraint system.
364 Better framework extendability and better support for "making your own
367 =head1 Version 0.25 or before
369 Honestly, you shouldn't be using versions of Moose that are this old,
370 so many bug fixes and speed improvements have been made you would be
371 crazy to not upgrade.
373 Also, I am tired of going through the Changelog so I am stopping here,
374 if anyone would like to continue this please feel free.
378 Stevan Little E<lt>stevan@iinteractive.comE<gt>
380 =head1 COPYRIGHT AND LICENSE
382 Copyright 2009 by Infinity Interactive, Inc.
384 L<http://www.iinteractive.com>
386 This library is free software; you can redistribute it and/or modify
387 it under the same terms as Perl itself.