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' }
33 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
34 and C<-excludes>. The old names still work, but new code should use the new
35 names, and eventually the old ones will be deprecated and removed.
39 When an attribute generates I<no> accessors, we now warn. This is to help
40 users who forget the C<is> option. If you really do not want any accessors,
41 you can use C<< is => 'bare' >>. You can maintain back compat with older
42 versions of Moose by using something like:
44 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
46 When an accessor overwrites an existing method, we now warn. To work around
47 this warning (if you really must have this behavior), you can explicitly
48 remove the method before creating it as an accessor:
52 __PACKAGE__->meta->remove_method('foo');
58 When an unknown option is passed to C<has>, we now warn. You can silence
59 the warning by fixing your code. :)
61 The C<Role> type has been deprecated. On its own, it was useless,
62 since it just checked C<< $object->can('does') >>. If you were using
63 it as a parent type, just call C<role_type('Role::Name')> to create an
64 appropriate type instead.
68 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
73 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
74 not we are in global destruction.
78 Type constraints no longer run coercions for a value that already matches the
79 constraint. This may affect some (arguably buggy) edge case coercions that
80 rely on side effects in the C<via> clause.
84 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
85 overriding the metaclass (without L<metaclass>). This works for classes
90 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
91 to make integration with non-Moose classes easier. It simply checks if
92 C<< $obj->can() >> a list of methods.
94 A number of methods (mostly inherited from L<Class::MOP>) have been
95 renamed with a leading underscore to indicate their internal-ness. The
96 old method names will still work for a while, but will warn that the
97 method has been renamed. In a few cases, the method will be removed
98 entirely in the future. This may affect MooseX authors who were using
103 Calling C<subtype> with a name as the only argument now throws an
104 exception. If you want an anonymous subtype do:
106 my $subtype = subtype as 'Foo';
108 This is related to the changes in version 0.71_01.
110 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
111 only usable as a class method. Previously, it worked as a class or
112 object method, with a different internal implementation for each
115 The internals of making a class immutable changed a lot in Class::MOP
116 0.78_02, and Moose's internals have changed along with it. The
117 external C<< $metaclass->make_immutable >> method still works the same
122 A mutable class accepted C<< Foo->new(undef) >> without complaint,
123 while an immutable class would blow up with an unhelpful error. Now,
124 in both cases we throw a helpful error instead.
126 This "feature" was originally added to allow for cases such as this:
134 return My::Class->new($args);
136 But we decided this is a bad idea and a little too magical, because it
137 can easily mask real errors.
139 =head1 Version 0.71_01
141 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
142 C<where>, C<message>) is now deprecated.
144 As a side effect, this meant we ended up using Perl prototypes on
145 C<as>, and code like this will no longer work:
147 use Moose::Util::TypeConstraints;
148 use Declare::Constraints::Simple -All;
150 subtype 'ArrayOfInts'
152 => IsArrayRef(IsInt);
154 Instead it must be changed to this:
159 where => IsArrayRef(IsInt)
163 If you want to maintain backwards compat with older versions of Moose,
164 you must explicitly test Moose's C<VERSION>:
166 if ( Moose->VERSION < 0.71_01 ) {
167 subtype 'ArrayOfInts'
169 => IsArrayRef(IsInt);
175 where => IsArrayRef(IsInt)
182 We no longer pass the meta-attribute object as a final argument to
183 triggers. This actually changed for inlined code a while back, but the
184 non-inlined version and the docs were still out of date.
186 If by some chance you actually used this feature, the workaround is
187 simple. You fetch the attribute object from out of the C<$self>
188 that is passed as the first argument to trigger, like so:
194 my ( $self, $value ) = @_;
195 my $attr = $self->meta->find_attribute_by_name('foo');
203 If you created a subtype and passed a parent that Moose didn't know
204 about, it simply ignored the parent. Now it automatically creates the
205 parent as a class type. This may not be what you want, but is less
208 You could declare a name with subtype such as "Foo!Bar". Moose would
209 accept this allowed, but if you used it in a parameterized type such
210 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
211 names created via the sugar functions, so that they can only contain
212 alphanumerics, ":", and ".".
216 Methods created via an attribute can now fulfill a C<requires>
217 declaration for a role. Honestly we don't know why Stevan didn't make
218 this work originally, he was just insane or something.
220 Stack traces from inlined code will now report the line and file as
221 being in your class, as opposed to in Moose guts.
223 =head1 Version 0.62_02
225 When a class does not provide all of a role's required methods, the
226 error thrown now mentions all of the missing methods, as opposed to
227 just the first missing method.
229 Moose will no longer inline a constructor for your class unless it
230 inherits its constructor from Moose::Object, and will warn when it
231 doesn't inline. If you want to force inlining anyway, pass
232 C<< replace_constructor => 1 >> to C<make_immutable>.
234 If you want to get rid of the warning, pass C<< inline_constructor =>
239 Removed the (deprecated) C<make_immutable> keyword.
241 Removing an attribute from a class now also removes delegation
242 (C<handles>) methods installed for that attribute. This is correct
243 behavior, but if you were wrongly relying on it you might get bit.
247 Roles now add methods by calling C<add_method>, not
248 C<alias_method>. They make sure to always provide a method object,
249 which will be cloned internally. This means that it is now possible to
250 track the source of a method provided by a role, and even follow its
251 history through intermediate roles. This means that methods added by
252 a role now show up when looking at a class's method list/map.
254 Parameter and Union args are now sorted, this makes Int|Str the same
255 constraint as Str|Int. Also, incoming type constraint strings are
256 normalized to remove all whitespace differences. This is mostly for
257 internals and should not affect outside code.
259 L<Moose::Exporter> will no longer remove a subroutine that the
260 exporting package re-exports. Moose re-exports the Carp::confess
261 function, among others. The reasoning is that we cannot know whether
262 you have also explicitly imported those functions for your own use, so
263 we err on the safe side and always keep them.
267 C<Moose::init_meta> should now be called as a method.
269 New modules for extension writers, L<Moose::Exporter> and
270 L<Moose::Util::MetaRole>.
272 =head1 Version 0.55_01
274 Implemented metaclass traits (and wrote a recipe for it):
276 use Moose -traits => 'Foo'
278 This should make writing small Moose extensions a little
283 Fixed C<coerce> to accept anon types just like C<subtype> can.
286 coerce $some_anon_type => from 'Str' => via { ... };
290 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
294 Fixed how the C<< is => (ro|rw) >> works with custom defined
295 C<reader>, C<writer> and C<accessor> options. See the below table for
298 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
299 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
300 is => rw, accessor => _foo # turns into (accessor => _foo)
301 is => ro, accessor => _foo # error, accesor is rw
305 The C<before/around/after> method modifiers now support regexp
306 matching of method names. NOTE: this only works for classes, it is
307 currently not supported in roles, but, ... patches welcome.
309 The C<has> keyword for roles now accepts the same array ref form that
310 L<Moose>.pm does for classes.
312 A trigger on a read-only attribute is no longer an error, as it's
313 useful to trigger off of the constructor.
315 Subtypes of parameterizable types now are parameterizable types
320 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
321 not working correctly. It still kind of eats them, but so does vanilla
326 Inherited attributes may now be extended without restriction on the
327 type ('isa', 'does').
329 The entire set of Moose::Meta::TypeConstraint::* classes were
330 refactored in this release. If you were relying on their internals you
331 should test your code carefully.
335 Documenting the use of '+name' with attributes that come from recently
336 composed roles. It makes sense, people are using it, and so why not
337 just officially support it.
339 The C<< Moose::Meta::Class->create >> method now supports roles.
341 It is now possible to make anonymous enum types by passing C<enum> an
342 array reference instead of the C<< enum $name => @values >>.
346 Added the C<make_immutable> keyword as a shortcut to calling
347 C<make_immutable> on the meta object. This eventually got removed!
349 Made C<< init_arg => undef >> work in Moose. This means "do not accept
350 a constructor parameter for this attribute".
352 Type errors now use the provided message. Prior to this release they
357 Moose is now a postmodern object system :)
359 The Role system was completely refactored. It is 100% backwards
360 compat, but the internals were totally changed. If you relied on the
361 internals then you are advised to test carefully.
363 Added method exclusion and aliasing for Roles in this release.
365 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
368 Passing a list of values to an accessor (which is only expecting one
369 value) used to be silently ignored, now it throws an error.
373 Added parameterized types and did a pretty heavy refactoring of the
374 type constraint system.
376 Better framework extendability and better support for "making your own
379 =head1 Version 0.25 or before
381 Honestly, you shouldn't be using versions of Moose that are this old,
382 so many bug fixes and speed improvements have been made you would be
383 crazy to not upgrade.
385 Also, I am tired of going through the Changelog so I am stopping here,
386 if anyone would like to continue this please feel free.
390 Stevan Little E<lt>stevan@iinteractive.comE<gt>
392 =head1 COPYRIGHT AND LICENSE
394 Copyright 2009 by Infinity Interactive, Inc.
396 L<http://www.iinteractive.com>
398 This library is free software; you can redistribute it and/or modify
399 it under the same terms as Perl itself.