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
23 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
25 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
29 =head1 Version 0.89_01
31 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
32 L<MooseX::AttributeHelpers>. Major changes include:
36 =item C<traits>, not C<metaclass>
38 Method providers are only available via traits.
40 =item C<handles>, not C<provides> or C<curries>
42 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
43 syntax, but with the keys and values reversed. This was confusing,
44 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
45 should be intuitive to anyone already familiar with how it is used for
48 The C<curries> functionality provided by AttributeHelpers has been
49 generalized to apply to all cases of C<< handles => HASHREF >>, though
50 not every piece of functionality has been ported (currying with a
51 CODEREF is not supported).
53 =item C<empty> is now C<is_empty>, and means empty, not non-empty
55 Previously, the C<empty> method provided by Arrays and Hashes returned true if
56 the attribute was B<not> empty (no elements). Now it returns true if the
57 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
59 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
61 L<List::Util> refers to the functionality that we used to provide under C<find>
62 as L<first|List::Util/first>, so that will likely be more familiar (and will
63 fit in better if we decide to add more List::Util functions). C<first> and
64 C<last> were removed, since their functionality is easily duplicated with
67 =item Helpers that take a coderef of one argument now use C<$_>
69 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
70 receive their argument in C<$_> rather than as a parameter to the subroutine.
71 Helpers that take a coderef of two or more arguments remain using the argument
72 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
75 See L<Moose::Meta::Attribute::Native> for the new documentation.
79 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
80 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
82 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
83 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
84 a wrapper around the old
86 package Moose::Meta::Class::Custom::Trait::FooTrait;
87 sub register_implementation { 'My::Meta::Trait' }
91 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
92 and C<-excludes>. The old names still work, but new code should use the new
93 names, and eventually the old ones will be deprecated and removed.
97 When an attribute generates I<no> accessors, we now warn. This is to help
98 users who forget the C<is> option. If you really do not want any accessors,
99 you can use C<< is => 'bare' >>. You can maintain back compat with older
100 versions of Moose by using something like:
102 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
104 When an accessor overwrites an existing method, we now warn. To work around
105 this warning (if you really must have this behavior), you can explicitly
106 remove the method before creating it as an accessor:
110 __PACKAGE__->meta->remove_method('foo');
116 When an unknown option is passed to C<has>, we now warn. You can silence
117 the warning by fixing your code. :)
119 The C<Role> type has been deprecated. On its own, it was useless,
120 since it just checked C<< $object->can('does') >>. If you were using
121 it as a parent type, just call C<role_type('Role::Name')> to create an
122 appropriate type instead.
126 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
131 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
132 not we are in global destruction.
136 Type constraints no longer run coercions for a value that already matches the
137 constraint. This may affect some (arguably buggy) edge case coercions that
138 rely on side effects in the C<via> clause.
142 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
143 overriding the metaclass (without L<metaclass>). This works for classes
148 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
149 to make integration with non-Moose classes easier. It simply checks if
150 C<< $obj->can() >> a list of methods.
152 A number of methods (mostly inherited from L<Class::MOP>) have been
153 renamed with a leading underscore to indicate their internal-ness. The
154 old method names will still work for a while, but will warn that the
155 method has been renamed. In a few cases, the method will be removed
156 entirely in the future. This may affect MooseX authors who were using
161 Calling C<subtype> with a name as the only argument now throws an
162 exception. If you want an anonymous subtype do:
164 my $subtype = subtype as 'Foo';
166 This is related to the changes in version 0.71_01.
168 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
169 only usable as a class method. Previously, it worked as a class or
170 object method, with a different internal implementation for each
173 The internals of making a class immutable changed a lot in Class::MOP
174 0.78_02, and Moose's internals have changed along with it. The
175 external C<< $metaclass->make_immutable >> method still works the same
180 A mutable class accepted C<< Foo->new(undef) >> without complaint,
181 while an immutable class would blow up with an unhelpful error. Now,
182 in both cases we throw a helpful error instead.
184 This "feature" was originally added to allow for cases such as this:
192 return My::Class->new($args);
194 But we decided this is a bad idea and a little too magical, because it
195 can easily mask real errors.
197 =head1 Version 0.71_01
199 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
200 C<where>, C<message>) is now deprecated.
202 As a side effect, this meant we ended up using Perl prototypes on
203 C<as>, and code like this will no longer work:
205 use Moose::Util::TypeConstraints;
206 use Declare::Constraints::Simple -All;
208 subtype 'ArrayOfInts'
210 => IsArrayRef(IsInt);
212 Instead it must be changed to this:
217 where => IsArrayRef(IsInt)
221 If you want to maintain backwards compat with older versions of Moose,
222 you must explicitly test Moose's C<VERSION>:
224 if ( Moose->VERSION < 0.71_01 ) {
225 subtype 'ArrayOfInts'
227 => IsArrayRef(IsInt);
233 where => IsArrayRef(IsInt)
240 We no longer pass the meta-attribute object as a final argument to
241 triggers. This actually changed for inlined code a while back, but the
242 non-inlined version and the docs were still out of date.
244 If by some chance you actually used this feature, the workaround is
245 simple. You fetch the attribute object from out of the C<$self>
246 that is passed as the first argument to trigger, like so:
252 my ( $self, $value ) = @_;
253 my $attr = $self->meta->find_attribute_by_name('foo');
261 If you created a subtype and passed a parent that Moose didn't know
262 about, it simply ignored the parent. Now it automatically creates the
263 parent as a class type. This may not be what you want, but is less
266 You could declare a name with subtype such as "Foo!Bar". Moose would
267 accept this allowed, but if you used it in a parameterized type such
268 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
269 names created via the sugar functions, so that they can only contain
270 alphanumerics, ":", and ".".
274 Methods created via an attribute can now fulfill a C<requires>
275 declaration for a role. Honestly we don't know why Stevan didn't make
276 this work originally, he was just insane or something.
278 Stack traces from inlined code will now report the line and file as
279 being in your class, as opposed to in Moose guts.
281 =head1 Version 0.62_02
283 When a class does not provide all of a role's required methods, the
284 error thrown now mentions all of the missing methods, as opposed to
285 just the first missing method.
287 Moose will no longer inline a constructor for your class unless it
288 inherits its constructor from Moose::Object, and will warn when it
289 doesn't inline. If you want to force inlining anyway, pass
290 C<< replace_constructor => 1 >> to C<make_immutable>.
292 If you want to get rid of the warning, pass C<< inline_constructor =>
297 Removed the (deprecated) C<make_immutable> keyword.
299 Removing an attribute from a class now also removes delegation
300 (C<handles>) methods installed for that attribute. This is correct
301 behavior, but if you were wrongly relying on it you might get bit.
305 Roles now add methods by calling C<add_method>, not
306 C<alias_method>. They make sure to always provide a method object,
307 which will be cloned internally. This means that it is now possible to
308 track the source of a method provided by a role, and even follow its
309 history through intermediate roles. This means that methods added by
310 a role now show up when looking at a class's method list/map.
312 Parameter and Union args are now sorted, this makes Int|Str the same
313 constraint as Str|Int. Also, incoming type constraint strings are
314 normalized to remove all whitespace differences. This is mostly for
315 internals and should not affect outside code.
317 L<Moose::Exporter> will no longer remove a subroutine that the
318 exporting package re-exports. Moose re-exports the Carp::confess
319 function, among others. The reasoning is that we cannot know whether
320 you have also explicitly imported those functions for your own use, so
321 we err on the safe side and always keep them.
325 C<Moose::init_meta> should now be called as a method.
327 New modules for extension writers, L<Moose::Exporter> and
328 L<Moose::Util::MetaRole>.
330 =head1 Version 0.55_01
332 Implemented metaclass traits (and wrote a recipe for it):
334 use Moose -traits => 'Foo'
336 This should make writing small Moose extensions a little
341 Fixed C<coerce> to accept anon types just like C<subtype> can.
344 coerce $some_anon_type => from 'Str' => via { ... };
348 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
352 Fixed how the C<< is => (ro|rw) >> works with custom defined
353 C<reader>, C<writer> and C<accessor> options. See the below table for
356 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
357 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
358 is => rw, accessor => _foo # turns into (accessor => _foo)
359 is => ro, accessor => _foo # error, accesor is rw
363 The C<before/around/after> method modifiers now support regexp
364 matching of method names. NOTE: this only works for classes, it is
365 currently not supported in roles, but, ... patches welcome.
367 The C<has> keyword for roles now accepts the same array ref form that
368 L<Moose>.pm does for classes.
370 A trigger on a read-only attribute is no longer an error, as it's
371 useful to trigger off of the constructor.
373 Subtypes of parameterizable types now are parameterizable types
378 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
379 not working correctly. It still kind of eats them, but so does vanilla
384 Inherited attributes may now be extended without restriction on the
385 type ('isa', 'does').
387 The entire set of Moose::Meta::TypeConstraint::* classes were
388 refactored in this release. If you were relying on their internals you
389 should test your code carefully.
393 Documenting the use of '+name' with attributes that come from recently
394 composed roles. It makes sense, people are using it, and so why not
395 just officially support it.
397 The C<< Moose::Meta::Class->create >> method now supports roles.
399 It is now possible to make anonymous enum types by passing C<enum> an
400 array reference instead of the C<< enum $name => @values >>.
404 Added the C<make_immutable> keyword as a shortcut to calling
405 C<make_immutable> on the meta object. This eventually got removed!
407 Made C<< init_arg => undef >> work in Moose. This means "do not accept
408 a constructor parameter for this attribute".
410 Type errors now use the provided message. Prior to this release they
415 Moose is now a postmodern object system :)
417 The Role system was completely refactored. It is 100% backwards
418 compat, but the internals were totally changed. If you relied on the
419 internals then you are advised to test carefully.
421 Added method exclusion and aliasing for Roles in this release.
423 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
426 Passing a list of values to an accessor (which is only expecting one
427 value) used to be silently ignored, now it throws an error.
431 Added parameterized types and did a pretty heavy refactoring of the
432 type constraint system.
434 Better framework extendability and better support for "making your own
437 =head1 Version 0.25 or before
439 Honestly, you shouldn't be using versions of Moose that are this old,
440 so many bug fixes and speed improvements have been made you would be
441 crazy to not upgrade.
443 Also, I am tired of going through the Changelog so I am stopping here,
444 if anyone would like to continue this please feel free.
448 Stevan Little E<lt>stevan@iinteractive.comE<gt>
450 =head1 COPYRIGHT AND LICENSE
452 Copyright 2009 by Infinity Interactive, Inc.
454 L<http://www.iinteractive.com>
456 This library is free software; you can redistribute it and/or modify
457 it under the same terms as Perl itself.