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 All of the method providers are available via traits only. The custom
29 metaclasses were strictly inferior to applying attribute metaclass traits.
31 =item C<handles>, not C<provides> or C<curries>
33 C<provides> syntax was like core Moose C<< handles => HASHREF >> syntax, but
34 with the keys and values reversed. This was confusing, and
35 AttributeHelpers now uses C<< handles => HASHREF >> in a way that
36 should be intuitive to anyone already familiar with it for normal attributes.
38 The C<curries> functionality provided by AttributeHelpers has been generalized
39 to apply to all cases of C<< handles => HASHREF >>, though not every piece of
40 functionality has been ported (currying with a CODEREF is not supported).
44 See L<Moose::AttributeHelpers> for the new documentation.
48 The C<Role> type has been deprecated. On its own, it was useless,
49 since it just checked C<< $object->can('does') >>. If you were using
50 it as a parent type, just call C<role_type('Role::Name')> to create an
51 appropriate type instead.
55 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
60 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
61 not we are in global destruction.
65 Type constraints no longer run coercions for a value that already matches the
66 constraint. This may affect some (arguably buggy) edge case coercions that
67 rely on side effects in the C<via> clause.
71 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
72 overriding the metaclass (without L<metaclass>). This works for classes
77 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
78 to make integration with non-Moose classes easier. It simply checks if
79 C<< $obj->can() >> a list of methods.
81 A number of methods (mostly inherited from L<Class::MOP>) have been
82 renamed with a leading underscore to indicate their internal-ness. The
83 old method names will still work for a while, but will warn that the
84 method has been renamed. In a few cases, the method will be removed
85 entirely in the future. This may affect MooseX authors who were using
90 Calling C<subtype> with a name as the only argument now throws an
91 exception. If you want an anonymous subtype do:
93 my $subtype = subtype as 'Foo';
95 This is related to the changes in version 0.71_01.
97 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
98 only usable as a class method. Previously, it worked as a class or
99 object method, with a different internal implementation for each
102 The internals of making a class immutable changed a lot in Class::MOP
103 0.78_02, and Moose's internals have changed along with it. The
104 external C<< $metaclass->make_immutable >> method still works the same
109 A mutable class accepted C<< Foo->new(undef) >> without complaint,
110 while an immutable class would blow up with an unhelpful error. Now,
111 in both cases we throw a helpful error instead.
113 This "feature" was originally added to allow for cases such as this:
121 return My::Class->new($args);
123 But we decided this is a bad idea and a little too magical, because it
124 can easily mask real errors.
126 =head1 Version 0.71_01
128 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
129 C<where>, C<message>) is now deprecated.
131 As a side effect, this meant we ended up using Perl prototypes on
132 C<as>, and code like this will no longer work:
134 use Moose::Util::TypeConstraints;
135 use Declare::Constraints::Simple -All;
137 subtype 'ArrayOfInts'
139 => IsArrayRef(IsInt);
141 Instead it must be changed to this:
146 where => IsArrayRef(IsInt)
150 If you want to maintain backwards compat with older versions of Moose,
151 you must explicitly test Moose's C<VERSION>:
153 if ( Moose->VERSION < 0.71_01 ) {
154 subtype 'ArrayOfInts'
156 => IsArrayRef(IsInt);
162 where => IsArrayRef(IsInt)
169 We no longer pass the meta-attribute object as a final argument to
170 triggers. This actually changed for inlined code a while back, but the
171 non-inlined version and the docs were still out of date.
173 If by some chance you actually used this feature, the workaround is
174 simple. You fetch the attribute object from out of the C<$self>
175 that is passed as the first argument to trigger, like so:
181 my ( $self, $value ) = @_;
182 my $attr = $self->meta->find_attribute_by_name('foo');
190 If you created a subtype and passed a parent that Moose didn't know
191 about, it simply ignored the parent. Now it automatically creates the
192 parent as a class type. This may not be what you want, but is less
195 You could declare a name with subtype such as "Foo!Bar". Moose would
196 accept this allowed, but if you used it in a parameterized type such
197 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
198 names created via the sugar functions, so that they can only contain
199 alphanumerics, ":", and ".".
203 Methods created via an attribute can now fulfill a C<requires>
204 declaration for a role. Honestly we don't know why Stevan didn't make
205 this work originally, he was just insane or something.
207 Stack traces from inlined code will now report the line and file as
208 being in your class, as opposed to in Moose guts.
210 =head1 Version 0.62_02
212 When a class does not provide all of a role's required methods, the
213 error thrown now mentions all of the missing methods, as opposed to
214 just the first missing method.
216 Moose will no longer inline a constructor for your class unless it
217 inherits its constructor from Moose::Object, and will warn when it
218 doesn't inline. If you want to force inlining anyway, pass
219 C<< "replace_constructor => 1 >> to C<make_immutable>.
221 If you want to get rid of the warning, pass C<< inline_constructor =>
226 Removed the (deprecated) C<make_immutable> keyword.
228 Removing an attribute from a class now also removes delegation
229 (C<handles>) methods installed for that attribute. This is correct
230 behavior, but if you were wrongly relying on it you might get bit.
234 Roles now add methods by calling C<add_method>, not
235 C<alias_method>. They make sure to always provide a method object,
236 which will be cloned internally. This means that it is now possible to
237 track the source of a method provided by a role, and even follow its
238 history through intermediate roles. This means that methods added by
239 a role now show up when looking at a class's method list/map.
241 Parameter and Union args are now sorted, this makes Int|Str the same
242 constraint as Str|Int. Also, incoming type constraint strings are
243 normalized to remove all whitespace differences. This is mostly for
244 internals and should not affect outside code.
246 L<Moose::Exporter> will no longer remove a subroutine that the
247 exporting package re-exports. Moose re-exports the Carp::confess
248 function, among others. The reasoning is that we cannot know whether
249 you have also explicitly imported those functions for your own use, so
250 we err on the safe side and always keep them.
254 C<Moose::init_meta> should now be called as a method.
256 New modules for extension writers, L<Moose::Exporter> and
257 L<Moose::Util::MetaRole>.
259 =head1 Version 0.55_01
261 Implemented metaclass traits (and wrote a recipe for it):
263 use Moose -traits => 'Foo'
265 This should make writing small Moose extensions a little
270 Fixed C<coerce> to accept anon types just like C<subtype> can.
273 coerce $some_anon_type => from 'Str' => via { ... };
277 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
281 Fixed how the C<< is => (ro|rw) >> works with custom defined
282 C<reader>, C<writer> and C<accessor> options. See the below table for
285 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
286 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
287 is => rw, accessor => _foo # turns into (accessor => _foo)
288 is => ro, accessor => _foo # error, accesor is rw
292 The C<before/around/after> method modifiers now support regexp
293 matching of method names. NOTE: this only works for classes, it is
294 currently not supported in roles, but, ... patches welcome.
296 The C<has> keyword for roles now accepts the same array ref form that
297 L<Moose>.pm does for classes.
299 A trigger on a read-only attribute is no longer an error, as it's
300 useful to trigger off of the constructor.
302 Subtypes of parameterizable types now are parameterizable types
307 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
308 not working correctly. It still kind of eats them, but so does vanilla
313 Inherited attributes may now be extended without restriction on the
314 type ('isa', 'does').
316 The entire set of Moose::Meta::TypeConstraint::* classes were
317 refactored in this release. If you were relying on their internals you
318 should test your code carefully.
322 Documenting the use of '+name' with attributes that come from recently
323 composed roles. It makes sense, people are using it, and so why not
324 just officially support it.
326 The C<< Moose::Meta::Class->create >> method now supports roles.
328 It is now possible to make anonymous enum types by passing C<enum> an
329 array reference instead of the C<< enum $name => @values >>.
333 Added the C<make_immutable> keyword as a shortcut to calling
334 C<make_immutable> on the meta object. This eventually got removed!
336 Made C<< init_arg => undef >> work in Moose. This means "do not accept
337 a constructor parameter for this attribute".
339 Type errors now use the provided message. Prior to this release they
344 Moose is now a postmodern object system :)
346 The Role system was completely refactored. It is 100% backwards
347 compat, but the internals were totally changed. If you relied on the
348 internals then you are advised to test carefully.
350 Added method exclusion and aliasing for Roles in this release.
352 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
355 Passing a list of values to an accessor (which is only expecting one
356 value) used to be silently ignored, now it throws an error.
360 Added parameterized types and did a pretty heavy refactoring of the
361 type constraint system.
363 Better framework extendability and better support for "making your own
366 =head1 Version 0.25 or before
368 Honestly, you shouldn't be using versions of Moose that are this old,
369 so many bug fixes and speed improvements have been made you would be
370 crazy to not upgrade.
372 Also, I am tired of going through the Changelog so I am stopping here,
373 if anyone would like to continue this please feel free.
377 Stevan Little E<lt>stevan@iinteractive.comE<gt>
379 =head1 COPYRIGHT AND LICENSE
381 Copyright 2009 by Infinity Interactive, Inc.
383 L<http://www.iinteractive.com>
385 This library is free software; you can redistribute it and/or modify
386 it under the same terms as Perl itself.