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 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
23 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
27 =head1 Version 0.89_01
29 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
30 L<MooseX::AttributeHelpers>. Major changes include:
34 =item C<traits>, not C<metaclass>
36 Method providers are only available via traits.
38 =item C<handles>, not C<provides> or C<curries>
40 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
41 syntax, but with the keys and values reversed. This was confusing,
42 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
43 should be intuitive to anyone already familiar with how it is used for
46 The C<curries> functionality provided by AttributeHelpers has been
47 generalized to apply to all cases of C<< handles => HASHREF >>, though
48 not every piece of functionality has been ported (currying with a
49 CODEREF is not supported).
51 =item C<empty> is now C<is_empty>, and means empty, not non-empty
53 Previously, the C<empty> method provided by Arrays and Hashes returned true if
54 the attribute was B<not> empty (no elements). Now it returns true if the
55 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
57 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
59 L<List::Util> refers to the functionality that we used to provide under C<find>
60 as L<first|List::Util/first>, so that will likely be more familiar (and will
61 fit in better if we decide to add more List::Util functions). C<first> and
62 C<last> were removed, since their functionality is easily duplicated with
65 =item Helpers that take a coderef of one argument now use C<$_>
67 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
68 receive their argument in C<$_> rather than as a parameter to the subroutine.
69 Helpers that take a coderef of two or more arguments remain using the argument
70 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
73 See L<Moose::Meta::Attribute::Native> for the new documentation.
77 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
78 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
80 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
81 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
82 a wrapper around the old
84 package Moose::Meta::Class::Custom::Trait::FooTrait;
85 sub register_implementation { 'My::Meta::Trait' }
89 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
90 and C<-excludes>. The old names still work, but new code should use the new
91 names, and eventually the old ones will be deprecated and removed.
95 When an attribute generates I<no> accessors, we now warn. This is to help
96 users who forget the C<is> option. If you really do not want any accessors,
97 you can use C<< is => 'bare' >>. You can maintain back compat with older
98 versions of Moose by using something like:
100 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
102 When an accessor overwrites an existing method, we now warn. To work around
103 this warning (if you really must have this behavior), you can explicitly
104 remove the method before creating it as an accessor:
108 __PACKAGE__->meta->remove_method('foo');
114 When an unknown option is passed to C<has>, we now warn. You can silence
115 the warning by fixing your code. :)
117 The C<Role> type has been deprecated. On its own, it was useless,
118 since it just checked C<< $object->can('does') >>. If you were using
119 it as a parent type, just call C<role_type('Role::Name')> to create an
120 appropriate type instead.
124 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
129 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
130 not we are in global destruction.
134 Type constraints no longer run coercions for a value that already matches the
135 constraint. This may affect some (arguably buggy) edge case coercions that
136 rely on side effects in the C<via> clause.
140 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
141 overriding the metaclass (without L<metaclass>). This works for classes
146 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
147 to make integration with non-Moose classes easier. It simply checks if
148 C<< $obj->can() >> a list of methods.
150 A number of methods (mostly inherited from L<Class::MOP>) have been
151 renamed with a leading underscore to indicate their internal-ness. The
152 old method names will still work for a while, but will warn that the
153 method has been renamed. In a few cases, the method will be removed
154 entirely in the future. This may affect MooseX authors who were using
159 Calling C<subtype> with a name as the only argument now throws an
160 exception. If you want an anonymous subtype do:
162 my $subtype = subtype as 'Foo';
164 This is related to the changes in version 0.71_01.
166 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
167 only usable as a class method. Previously, it worked as a class or
168 object method, with a different internal implementation for each
171 The internals of making a class immutable changed a lot in Class::MOP
172 0.78_02, and Moose's internals have changed along with it. The
173 external C<< $metaclass->make_immutable >> method still works the same
178 A mutable class accepted C<< Foo->new(undef) >> without complaint,
179 while an immutable class would blow up with an unhelpful error. Now,
180 in both cases we throw a helpful error instead.
182 This "feature" was originally added to allow for cases such as this:
190 return My::Class->new($args);
192 But we decided this is a bad idea and a little too magical, because it
193 can easily mask real errors.
195 =head1 Version 0.71_01
197 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
198 C<where>, C<message>) is now deprecated.
200 As a side effect, this meant we ended up using Perl prototypes on
201 C<as>, and code like this will no longer work:
203 use Moose::Util::TypeConstraints;
204 use Declare::Constraints::Simple -All;
206 subtype 'ArrayOfInts'
208 => IsArrayRef(IsInt);
210 Instead it must be changed to this:
215 where => IsArrayRef(IsInt)
219 If you want to maintain backwards compat with older versions of Moose,
220 you must explicitly test Moose's C<VERSION>:
222 if ( Moose->VERSION < 0.71_01 ) {
223 subtype 'ArrayOfInts'
225 => IsArrayRef(IsInt);
231 where => IsArrayRef(IsInt)
238 We no longer pass the meta-attribute object as a final argument to
239 triggers. This actually changed for inlined code a while back, but the
240 non-inlined version and the docs were still out of date.
242 If by some chance you actually used this feature, the workaround is
243 simple. You fetch the attribute object from out of the C<$self>
244 that is passed as the first argument to trigger, like so:
250 my ( $self, $value ) = @_;
251 my $attr = $self->meta->find_attribute_by_name('foo');
259 If you created a subtype and passed a parent that Moose didn't know
260 about, it simply ignored the parent. Now it automatically creates the
261 parent as a class type. This may not be what you want, but is less
264 You could declare a name with subtype such as "Foo!Bar". Moose would
265 accept this allowed, but if you used it in a parameterized type such
266 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
267 names created via the sugar functions, so that they can only contain
268 alphanumerics, ":", and ".".
272 Methods created via an attribute can now fulfill a C<requires>
273 declaration for a role. Honestly we don't know why Stevan didn't make
274 this work originally, he was just insane or something.
276 Stack traces from inlined code will now report the line and file as
277 being in your class, as opposed to in Moose guts.
279 =head1 Version 0.62_02
281 When a class does not provide all of a role's required methods, the
282 error thrown now mentions all of the missing methods, as opposed to
283 just the first missing method.
285 Moose will no longer inline a constructor for your class unless it
286 inherits its constructor from Moose::Object, and will warn when it
287 doesn't inline. If you want to force inlining anyway, pass
288 C<< replace_constructor => 1 >> to C<make_immutable>.
290 If you want to get rid of the warning, pass C<< inline_constructor =>
295 Removed the (deprecated) C<make_immutable> keyword.
297 Removing an attribute from a class now also removes delegation
298 (C<handles>) methods installed for that attribute. This is correct
299 behavior, but if you were wrongly relying on it you might get bit.
303 Roles now add methods by calling C<add_method>, not
304 C<alias_method>. They make sure to always provide a method object,
305 which will be cloned internally. This means that it is now possible to
306 track the source of a method provided by a role, and even follow its
307 history through intermediate roles. This means that methods added by
308 a role now show up when looking at a class's method list/map.
310 Parameter and Union args are now sorted, this makes Int|Str the same
311 constraint as Str|Int. Also, incoming type constraint strings are
312 normalized to remove all whitespace differences. This is mostly for
313 internals and should not affect outside code.
315 L<Moose::Exporter> will no longer remove a subroutine that the
316 exporting package re-exports. Moose re-exports the Carp::confess
317 function, among others. The reasoning is that we cannot know whether
318 you have also explicitly imported those functions for your own use, so
319 we err on the safe side and always keep them.
323 C<Moose::init_meta> should now be called as a method.
325 New modules for extension writers, L<Moose::Exporter> and
326 L<Moose::Util::MetaRole>.
328 =head1 Version 0.55_01
330 Implemented metaclass traits (and wrote a recipe for it):
332 use Moose -traits => 'Foo'
334 This should make writing small Moose extensions a little
339 Fixed C<coerce> to accept anon types just like C<subtype> can.
342 coerce $some_anon_type => from 'Str' => via { ... };
346 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
350 Fixed how the C<< is => (ro|rw) >> works with custom defined
351 C<reader>, C<writer> and C<accessor> options. See the below table for
354 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
355 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
356 is => rw, accessor => _foo # turns into (accessor => _foo)
357 is => ro, accessor => _foo # error, accesor is rw
361 The C<before/around/after> method modifiers now support regexp
362 matching of method names. NOTE: this only works for classes, it is
363 currently not supported in roles, but, ... patches welcome.
365 The C<has> keyword for roles now accepts the same array ref form that
366 L<Moose>.pm does for classes.
368 A trigger on a read-only attribute is no longer an error, as it's
369 useful to trigger off of the constructor.
371 Subtypes of parameterizable types now are parameterizable types
376 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
377 not working correctly. It still kind of eats them, but so does vanilla
382 Inherited attributes may now be extended without restriction on the
383 type ('isa', 'does').
385 The entire set of Moose::Meta::TypeConstraint::* classes were
386 refactored in this release. If you were relying on their internals you
387 should test your code carefully.
391 Documenting the use of '+name' with attributes that come from recently
392 composed roles. It makes sense, people are using it, and so why not
393 just officially support it.
395 The C<< Moose::Meta::Class->create >> method now supports roles.
397 It is now possible to make anonymous enum types by passing C<enum> an
398 array reference instead of the C<< enum $name => @values >>.
402 Added the C<make_immutable> keyword as a shortcut to calling
403 C<make_immutable> on the meta object. This eventually got removed!
405 Made C<< init_arg => undef >> work in Moose. This means "do not accept
406 a constructor parameter for this attribute".
408 Type errors now use the provided message. Prior to this release they
413 Moose is now a postmodern object system :)
415 The Role system was completely refactored. It is 100% backwards
416 compat, but the internals were totally changed. If you relied on the
417 internals then you are advised to test carefully.
419 Added method exclusion and aliasing for Roles in this release.
421 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
424 Passing a list of values to an accessor (which is only expecting one
425 value) used to be silently ignored, now it throws an error.
429 Added parameterized types and did a pretty heavy refactoring of the
430 type constraint system.
432 Better framework extendability and better support for "making your own
435 =head1 Version 0.25 or before
437 Honestly, you shouldn't be using versions of Moose that are this old,
438 so many bug fixes and speed improvements have been made you would be
439 crazy to not upgrade.
441 Also, I am tired of going through the Changelog so I am stopping here,
442 if anyone would like to continue this please feel free.
446 Stevan Little E<lt>stevan@iinteractive.comE<gt>
448 =head1 COPYRIGHT AND LICENSE
450 Copyright 2009 by Infinity Interactive, Inc.
452 L<http://www.iinteractive.com>
454 This library is free software; you can redistribute it and/or modify
455 it under the same terms as Perl itself.