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' >>. You can maintain back compat with older
24 versions of Moose by using something like:
26 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
28 When an accessor overwrites an existing method, we now warn. To work around
29 this warning (if you really must have this behavior), you can explicitly
30 remove the method before creating it as an accessor:
34 __PACKAGE__->meta->remove_method('foo');
40 When an unknown option is passed to C<has>, we now warn. You can silence
41 the warning by fixing your code. :)
43 The C<Role> type has been deprecated. On its own, it was useless,
44 since it just checked C<< $object->can('does') >>. If you were using
45 it as a parent type, just call C<role_type('Role::Name')> to create an
46 appropriate type instead.
50 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
55 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
56 not we are in global destruction.
60 Type constraints no longer run coercions for a value that already matches the
61 constraint. This may affect some (arguably buggy) edge case coercions that
62 rely on side effects in the C<via> clause.
66 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
67 overriding the metaclass (without L<metaclass>). This works for classes
72 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
73 to make integration with non-Moose classes easier. It simply checks if
74 C<< $obj->can() >> a list of methods.
76 A number of methods (mostly inherited from L<Class::MOP>) have been
77 renamed with a leading underscore to indicate their internal-ness. The
78 old method names will still work for a while, but will warn that the
79 method has been renamed. In a few cases, the method will be removed
80 entirely in the future. This may affect MooseX authors who were using
85 Calling C<subtype> with a name as the only argument now throws an
86 exception. If you want an anonymous subtype do:
88 my $subtype = subtype as 'Foo';
90 This is related to the changes in version 0.71_01.
92 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
93 only usable as a class method. Previously, it worked as a class or
94 object method, with a different internal implementation for each
97 The internals of making a class immutable changed a lot in Class::MOP
98 0.78_02, and Moose's internals have changed along with it. The
99 external C<< $metaclass->make_immutable >> method still works the same
104 A mutable class accepted C<< Foo->new(undef) >> without complaint,
105 while an immutable class would blow up with an unhelpful error. Now,
106 in both cases we throw a helpful error instead.
108 This "feature" was originally added to allow for cases such as this:
116 return My::Class->new($args);
118 But we decided this is a bad idea and a little too magical, because it
119 can easily mask real errors.
121 =head1 Version 0.71_01
123 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
124 C<where>, C<message>) is now deprecated.
126 As a side effect, this meant we ended up using Perl prototypes on
127 C<as>, and code like this will no longer work:
129 use Moose::Util::TypeConstraints;
130 use Declare::Constraints::Simple -All;
132 subtype 'ArrayOfInts'
134 => IsArrayRef(IsInt);
136 Instead it must be changed to this:
141 where => IsArrayRef(IsInt)
145 If you want to maintain backwards compat with older versions of Moose,
146 you must explicitly test Moose's C<VERSION>:
148 if ( Moose->VERSION < 0.71_01 ) {
149 subtype 'ArrayOfInts'
151 => IsArrayRef(IsInt);
157 where => IsArrayRef(IsInt)
164 We no longer pass the meta-attribute object as a final argument to
165 triggers. This actually changed for inlined code a while back, but the
166 non-inlined version and the docs were still out of date.
168 If by some chance you actually used this feature, the workaround is
169 simple. You fetch the attribute object from out of the C<$self>
170 that is passed as the first argument to trigger, like so:
176 my ( $self, $value ) = @_;
177 my $attr = $self->meta->find_attribute_by_name('foo');
185 If you created a subtype and passed a parent that Moose didn't know
186 about, it simply ignored the parent. Now it automatically creates the
187 parent as a class type. This may not be what you want, but is less
190 You could declare a name with subtype such as "Foo!Bar". Moose would
191 accept this allowed, but if you used it in a parameterized type such
192 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
193 names created via the sugar functions, so that they can only contain
194 alphanumerics, ":", and ".".
198 Methods created via an attribute can now fulfill a C<requires>
199 declaration for a role. Honestly we don't know why Stevan didn't make
200 this work originally, he was just insane or something.
202 Stack traces from inlined code will now report the line and file as
203 being in your class, as opposed to in Moose guts.
205 =head1 Version 0.62_02
207 When a class does not provide all of a role's required methods, the
208 error thrown now mentions all of the missing methods, as opposed to
209 just the first missing method.
211 Moose will no longer inline a constructor for your class unless it
212 inherits its constructor from Moose::Object, and will warn when it
213 doesn't inline. If you want to force inlining anyway, pass
214 C<< replace_constructor => 1 >> to C<make_immutable>.
216 If you want to get rid of the warning, pass C<< inline_constructor =>
221 Removed the (deprecated) C<make_immutable> keyword.
223 Removing an attribute from a class now also removes delegation
224 (C<handles>) methods installed for that attribute. This is correct
225 behavior, but if you were wrongly relying on it you might get bit.
229 Roles now add methods by calling C<add_method>, not
230 C<alias_method>. They make sure to always provide a method object,
231 which will be cloned internally. This means that it is now possible to
232 track the source of a method provided by a role, and even follow its
233 history through intermediate roles. This means that methods added by
234 a role now show up when looking at a class's method list/map.
236 Parameter and Union args are now sorted, this makes Int|Str the same
237 constraint as Str|Int. Also, incoming type constraint strings are
238 normalized to remove all whitespace differences. This is mostly for
239 internals and should not affect outside code.
241 L<Moose::Exporter> will no longer remove a subroutine that the
242 exporting package re-exports. Moose re-exports the Carp::confess
243 function, among others. The reasoning is that we cannot know whether
244 you have also explicitly imported those functions for your own use, so
245 we err on the safe side and always keep them.
249 C<Moose::init_meta> should now be called as a method.
251 New modules for extension writers, L<Moose::Exporter> and
252 L<Moose::Util::MetaRole>.
254 =head1 Version 0.55_01
256 Implemented metaclass traits (and wrote a recipe for it):
258 use Moose -traits => 'Foo'
260 This should make writing small Moose extensions a little
265 Fixed C<coerce> to accept anon types just like C<subtype> can.
268 coerce $some_anon_type => from 'Str' => via { ... };
272 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
276 Fixed how the C<< is => (ro|rw) >> works with custom defined
277 C<reader>, C<writer> and C<accessor> options. See the below table for
280 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
281 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
282 is => rw, accessor => _foo # turns into (accessor => _foo)
283 is => ro, accessor => _foo # error, accesor is rw
287 The C<before/around/after> method modifiers now support regexp
288 matching of method names. NOTE: this only works for classes, it is
289 currently not supported in roles, but, ... patches welcome.
291 The C<has> keyword for roles now accepts the same array ref form that
292 L<Moose>.pm does for classes.
294 A trigger on a read-only attribute is no longer an error, as it's
295 useful to trigger off of the constructor.
297 Subtypes of parameterizable types now are parameterizable types
302 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
303 not working correctly. It still kind of eats them, but so does vanilla
308 Inherited attributes may now be extended without restriction on the
309 type ('isa', 'does').
311 The entire set of Moose::Meta::TypeConstraint::* classes were
312 refactored in this release. If you were relying on their internals you
313 should test your code carefully.
317 Documenting the use of '+name' with attributes that come from recently
318 composed roles. It makes sense, people are using it, and so why not
319 just officially support it.
321 The C<< Moose::Meta::Class->create >> method now supports roles.
323 It is now possible to make anonymous enum types by passing C<enum> an
324 array reference instead of the C<< enum $name => @values >>.
328 Added the C<make_immutable> keyword as a shortcut to calling
329 C<make_immutable> on the meta object. This eventually got removed!
331 Made C<< init_arg => undef >> work in Moose. This means "do not accept
332 a constructor parameter for this attribute".
334 Type errors now use the provided message. Prior to this release they
339 Moose is now a postmodern object system :)
341 The Role system was completely refactored. It is 100% backwards
342 compat, but the internals were totally changed. If you relied on the
343 internals then you are advised to test carefully.
345 Added method exclusion and aliasing for Roles in this release.
347 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
350 Passing a list of values to an accessor (which is only expecting one
351 value) used to be silently ignored, now it throws an error.
355 Added parameterized types and did a pretty heavy refactoring of the
356 type constraint system.
358 Better framework extendability and better support for "making your own
361 =head1 Version 0.25 or before
363 Honestly, you shouldn't be using versions of Moose that are this old,
364 so many bug fixes and speed improvements have been made you would be
365 crazy to not upgrade.
367 Also, I am tired of going through the Changelog so I am stopping here,
368 if anyone would like to continue this please feel free.
372 Stevan Little E<lt>stevan@iinteractive.comE<gt>
374 =head1 COPYRIGHT AND LICENSE
376 Copyright 2009 by Infinity Interactive, Inc.
378 L<http://www.iinteractive.com>
380 This library is free software; you can redistribute it and/or modify
381 it under the same terms as Perl itself.