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 When an attribute generates I<no> accessors, we now warn. This is to help
22 users who forget the C<is> option. If you really do not want any accessors,
23 you can use C<< is => 'bare' >>.
25 When an accessor overwrites an existing method, we now warn. To work around
26 this warning (if you really must have this behavior), you can explicitly
27 remove the method before creating it as an accessor:
31 __PACKAGE__->meta->remove_method('foo');
37 When an unknown option is passed to C<has>, we now warn. You can silence
38 the warning by fixing your code. :)
40 The C<Role> type has been deprecated. On its own, it was useless,
41 since it just checked C<< $object->can('does') >>. If you were using
42 it as a parent type, just call C<role_type('Role::Name')> to create an
43 appropriate type instead.
47 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
52 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
53 not we are in global destruction.
57 Type constraints no longer run coercions for a value that already matches the
58 constraint. This may affect some (arguably buggy) edge case coercions that
59 rely on side effects in the C<via> clause.
63 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
64 overriding the metaclass (without L<metaclass>). This works for classes
69 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
70 to make integration with non-Moose classes easier. It simply checks if
71 C<< $obj->can() >> a list of methods.
73 A number of methods (mostly inherited from L<Class::MOP>) have been
74 renamed with a leading underscore to indicate their internal-ness. The
75 old method names will still work for a while, but will warn that the
76 method has been renamed. In a few cases, the method will be removed
77 entirely in the future. This may affect MooseX authors who were using
82 Calling C<subtype> with a name as the only argument now throws an
83 exception. If you want an anonymous subtype do:
85 my $subtype = subtype as 'Foo';
87 This is related to the changes in version 0.71_01.
89 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
90 only usable as a class method. Previously, it worked as a class or
91 object method, with a different internal implementation for each
94 The internals of making a class immutable changed a lot in Class::MOP
95 0.78_02, and Moose's internals have changed along with it. The
96 external C<< $metaclass->make_immutable >> method still works the same
101 A mutable class accepted C<< Foo->new(undef) >> without complaint,
102 while an immutable class would blow up with an unhelpful error. Now,
103 in both cases we throw a helpful error instead.
105 This "feature" was originally added to allow for cases such as this:
113 return My::Class->new($args);
115 But we decided this is a bad idea and a little too magical, because it
116 can easily mask real errors.
118 =head1 Version 0.71_01
120 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
121 C<where>, C<message>) is now deprecated.
123 As a side effect, this meant we ended up using Perl prototypes on
124 C<as>, and code like this will no longer work:
126 use Moose::Util::TypeConstraints;
127 use Declare::Constraints::Simple -All;
129 subtype 'ArrayOfInts'
131 => IsArrayRef(IsInt);
133 Instead it must be changed to this:
138 where => IsArrayRef(IsInt)
142 If you want to maintain backwards compat with older versions of Moose,
143 you must explicitly test Moose's C<VERSION>:
145 if ( Moose->VERSION < 0.71_01 ) {
146 subtype 'ArrayOfInts'
148 => IsArrayRef(IsInt);
154 where => IsArrayRef(IsInt)
161 We no longer pass the meta-attribute object as a final argument to
162 triggers. This actually changed for inlined code a while back, but the
163 non-inlined version and the docs were still out of date.
165 If by some chance you actually used this feature, the workaround is
166 simple. You fetch the attribute object from out of the C<$self>
167 that is passed as the first argument to trigger, like so:
173 my ( $self, $value ) = @_;
174 my $attr = $self->meta->find_attribute_by_name('foo');
182 If you created a subtype and passed a parent that Moose didn't know
183 about, it simply ignored the parent. Now it automatically creates the
184 parent as a class type. This may not be what you want, but is less
187 You could declare a name with subtype such as "Foo!Bar". Moose would
188 accept this allowed, but if you used it in a parameterized type such
189 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
190 names created via the sugar functions, so that they can only contain
191 alphanumerics, ":", and ".".
195 Methods created via an attribute can now fulfill a C<requires>
196 declaration for a role. Honestly we don't know why Stevan didn't make
197 this work originally, he was just insane or something.
199 Stack traces from inlined code will now report the line and file as
200 being in your class, as opposed to in Moose guts.
202 =head1 Version 0.62_02
204 When a class does not provide all of a role's required methods, the
205 error thrown now mentions all of the missing methods, as opposed to
206 just the first missing method.
208 Moose will no longer inline a constructor for your class unless it
209 inherits its constructor from Moose::Object, and will warn when it
210 doesn't inline. If you want to force inlining anyway, pass
211 C<< replace_constructor => 1 >> to C<make_immutable>.
213 If you want to get rid of the warning, pass C<< inline_constructor =>
218 Removed the (deprecated) C<make_immutable> keyword.
220 Removing an attribute from a class now also removes delegation
221 (C<handles>) methods installed for that attribute. This is correct
222 behavior, but if you were wrongly relying on it you might get bit.
226 Roles now add methods by calling C<add_method>, not
227 C<alias_method>. They make sure to always provide a method object,
228 which will be cloned internally. This means that it is now possible to
229 track the source of a method provided by a role, and even follow its
230 history through intermediate roles. This means that methods added by
231 a role now show up when looking at a class's method list/map.
233 Parameter and Union args are now sorted, this makes Int|Str the same
234 constraint as Str|Int. Also, incoming type constraint strings are
235 normalized to remove all whitespace differences. This is mostly for
236 internals and should not affect outside code.
238 L<Moose::Exporter> will no longer remove a subroutine that the
239 exporting package re-exports. Moose re-exports the Carp::confess
240 function, among others. The reasoning is that we cannot know whether
241 you have also explicitly imported those functions for your own use, so
242 we err on the safe side and always keep them.
246 C<Moose::init_meta> should now be called as a method.
248 New modules for extension writers, L<Moose::Exporter> and
249 L<Moose::Util::MetaRole>.
251 =head1 Version 0.55_01
253 Implemented metaclass traits (and wrote a recipe for it):
255 use Moose -traits => 'Foo'
257 This should make writing small Moose extensions a little
262 Fixed C<coerce> to accept anon types just like C<subtype> can.
265 coerce $some_anon_type => from 'Str' => via { ... };
269 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
273 Fixed how the C<< is => (ro|rw) >> works with custom defined
274 C<reader>, C<writer> and C<accessor> options. See the below table for
277 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
278 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
279 is => rw, accessor => _foo # turns into (accessor => _foo)
280 is => ro, accessor => _foo # error, accesor is rw
284 The C<before/around/after> method modifiers now support regexp
285 matching of method names. NOTE: this only works for classes, it is
286 currently not supported in roles, but, ... patches welcome.
288 The C<has> keyword for roles now accepts the same array ref form that
289 L<Moose>.pm does for classes.
291 A trigger on a read-only attribute is no longer an error, as it's
292 useful to trigger off of the constructor.
294 Subtypes of parameterizable types now are parameterizable types
299 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
300 not working correctly. It still kind of eats them, but so does vanilla
305 Inherited attributes may now be extended without restriction on the
306 type ('isa', 'does').
308 The entire set of Moose::Meta::TypeConstraint::* classes were
309 refactored in this release. If you were relying on their internals you
310 should test your code carefully.
314 Documenting the use of '+name' with attributes that come from recently
315 composed roles. It makes sense, people are using it, and so why not
316 just officially support it.
318 The C<< Moose::Meta::Class->create >> method now supports roles.
320 It is now possible to make anonymous enum types by passing C<enum> an
321 array reference instead of the C<< enum $name => @values >>.
325 Added the C<make_immutable> keyword as a shortcut to calling
326 C<make_immutable> on the meta object. This eventually got removed!
328 Made C<< init_arg => undef >> work in Moose. This means "do not accept
329 a constructor parameter for this attribute".
331 Type errors now use the provided message. Prior to this release they
336 Moose is now a postmodern object system :)
338 The Role system was completely refactored. It is 100% backwards
339 compat, but the internals were totally changed. If you relied on the
340 internals then you are advised to test carefully.
342 Added method exclusion and aliasing for Roles in this release.
344 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
347 Passing a list of values to an accessor (which is only expecting one
348 value) used to be silently ignored, now it throws an error.
352 Added parameterized types and did a pretty heavy refactoring of the
353 type constraint system.
355 Better framework extendability and better support for "making your own
358 =head1 Version 0.25 or before
360 Honestly, you shouldn't be using versions of Moose that are this old,
361 so many bug fixes and speed improvements have been made you would be
362 crazy to not upgrade.
364 Also, I am tired of going through the Changelog so I am stopping here,
365 if anyone would like to continue this please feel free.
369 Stevan Little E<lt>stevan@iinteractive.comE<gt>
371 =head1 COPYRIGHT AND LICENSE
373 Copyright 2009 by Infinity Interactive, Inc.
375 L<http://www.iinteractive.com>
377 This library is free software; you can redistribute it and/or modify
378 it under the same terms as Perl itself.