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<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
22 not we are in global destruction.
26 Type constraints no longer run coercions for a value that already matches the
27 constraint. This may affect some (arguably buggy) edge case coercions that
28 rely on side effects in the C<via> clause.
32 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
33 overriding the metaclass (without L<metaclass>). This works for classes
38 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
39 to make integration with non-Moose classes easier. It simply checks if
40 C<< $obj->can() >> a list of methods.
42 A number of methods (mostly inherited from L<Class::MOP>) have been
43 renamed with a leading underscore to indicate their internal-ness. The
44 old method names will still work for a while, but will warn that the
45 method has been renamed. In a few cases, the method will be removed
46 entirely in the future. This may affect MooseX authors who were using
51 Calling C<subtype> with a name as the only argument now throws an
52 exception. If you want an anonymous subtype do:
54 my $subtype = subtype as 'Foo';
56 This is related to the changes in version 0.71_01.
58 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
59 only usable as a class method. Previously, it worked as a class or
60 object method, with a different internal implementation for each
63 The internals of making a class immutable changed a lot in Class::MOP
64 0.78_02, and Moose's internals have changed along with it. The
65 external C<< $metaclass->make_immutable >> method still works the same
70 A mutable class accepted C<< Foo->new(undef) >> without complaint,
71 while an immutable class would blow up with an unhelpful error. Now,
72 in both cases we throw a helpful error instead.
74 This "feature" was originally added to allow for cases such as this:
82 return My::Class->new($args);
84 But we decided this is a bad idea and a little too magical, because it
85 can easily mask real errors.
87 =head1 Version 0.71_01
89 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
90 C<where>, C<message>) is now deprecated.
92 As a side effect, this meant we ended up using Perl prototypes on
93 C<as>, and code like this will no longer work:
95 use Moose::Util::TypeConstraints;
96 use Declare::Constraints::Simple -All;
100 => IsArrayRef(IsInt);
102 Instead it must be changed to this:
107 where => IsArrayRef(IsInt)
111 If you want to maintain backwards compat with older versions of Moose,
112 you must explicitly test Moose's C<VERSION>:
114 if ( Moose->VERSION < 0.71_01 ) {
115 subtype 'ArrayOfInts'
117 => IsArrayRef(IsInt);
123 where => IsArrayRef(IsInt)
130 We no longer pass the meta-attribute object as a final argument to
131 triggers. This actually changed for inlined code a while back, but the
132 non-inlined version and the docs were still out of date.
134 If by some chance you actually used this feature, the workaround is
135 simple. You fetch the attribute object from out of the C<$self>
136 that is passed as the first argument to trigger, like so:
142 my ( $self, $value ) = @_;
143 my $attr = $self->meta->find_attribute_by_name('foo');
151 If you created a subtype and passed a parent that Moose didn't know
152 about, it simply ignored the parent. Now it automatically creates the
153 parent as a class type. This may not be what you want, but is less
156 You could declare a name with subtype such as "Foo!Bar". Moose would
157 accept this allowed, but if you used it in a parameterized type such
158 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
159 names created via the sugar functions, so that they can only contain
160 alphanumerics, ":", and ".".
164 Methods created via an attribute can now fulfill a C<requires>
165 declaration for a role. Honestly we don't know why Stevan didn't make
166 this work originally, he was just insane or something.
168 Stack traces from inlined code will now report the line and file as
169 being in your class, as opposed to in Moose guts.
171 =head1 Version 0.62_02
173 When a class does not provide all of a role's required methods, the
174 error thrown now mentions all of the missing methods, as opposed to
175 just the first missing method.
177 Moose will no longer inline a constructor for your class unless it
178 inherits its constructor from Moose::Object, and will warn when it
179 doesn't inline. If you want to force inlining anyway, pass
180 C<< "replace_constructor => 1 >> to C<make_immutable>.
182 If you want to get rid of the warning, pass C<< inline_constructor =>
187 Removed the (deprecated) C<make_immutable> keyword.
189 Removing an attribute from a class now also removes delegation
190 (C<handles>) methods installed for that attribute. This is correct
191 behavior, but if you were wrongly relying on it you might get bit.
195 Roles now add methods by calling C<add_method>, not
196 C<alias_method>. They make sure to always provide a method object,
197 which will be cloned internally. This means that it is now possible to
198 track the source of a method provided by a role, and even follow its
199 history through intermediate roles. This means that methods added by
200 a role now show up when looking at a class's method list/map.
202 Parameter and Union args are now sorted, this makes Int|Str the same
203 constraint as Str|Int. Also, incoming type constraint strings are
204 normalized to remove all whitespace differences. This is mostly for
205 internals and should not affect outside code.
207 L<Moose::Exporter> will no longer remove a subroutine that the
208 exporting package re-exports. Moose re-exports the Carp::confess
209 function, among others. The reasoning is that we cannot know whether
210 you have also explicitly imported those functions for your own use, so
211 we err on the safe side and always keep them.
215 C<Moose::init_meta> should now be called as a method.
217 New modules for extension writers, L<Moose::Exporter> and
218 L<Moose::Util::MetaRole>.
220 =head1 Version 0.55_01
222 Implemented metaclass traits (and wrote a recipe for it):
224 use Moose -traits => 'Foo'
226 This should make writing small Moose extensions a little
231 Fixed C<coerce> to accept anon types just like C<subtype> can.
234 coerce $some_anon_type => from 'Str' => via { ... };
238 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
242 Fixed how the C<< is => (ro|rw) >> works with custom defined
243 C<reader>, C<writer> and C<accessor> options. See the below table for
246 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
247 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
248 is => rw, accessor => _foo # turns into (accessor => _foo)
249 is => ro, accessor => _foo # error, accesor is rw
253 The C<before/around/after> method modifiers now support regexp
254 matching of method names. NOTE: this only works for classes, it is
255 currently not supported in roles, but, ... patches welcome.
257 The C<has> keyword for roles now accepts the same array ref form that
258 L<Moose>.pm does for classes.
260 A trigger on a read-only attribute is no longer an error, as it's
261 useful to trigger off of the constructor.
263 Subtypes of parameterizable types now are parameterizable types
268 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
269 not working correctly. It still kind of eats them, but so does vanilla
274 Inherited attributes may now be extended without restriction on the
275 type ('isa', 'does').
277 The entire set of Moose::Meta::TypeConstraint::* classes were
278 refactored in this release. If you were relying on their internals you
279 should test your code carefully.
283 Documenting the use of '+name' with attributes that come from recently
284 composed roles. It makes sense, people are using it, and so why not
285 just officially support it.
287 The C<< Moose::Meta::Class->create >> method now supports roles.
289 It is now possible to make anonymous enum types by passing C<enum> an
290 array reference instead of the C<< enum $name => @values >>.
294 Added the C<make_immutable> keyword as a shortcut to calling
295 C<make_immutable> on the meta object. This eventually got removed!
297 Made C<< init_arg => undef >> work in Moose. This means "do not accept
298 a constructor parameter for this attribute".
300 Type errors now use the provided message. Prior to this release they
305 Moose is now a postmodern object system :)
307 The Role system was completely refactored. It is 100% backwards
308 compat, but the internals were totally changed. If you relied on the
309 internals then you are advised to test carefully.
311 Added method exclusion and aliasing for Roles in this release.
313 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
316 Passing a list of values to an accessor (which is only expecting one
317 value) used to be silently ignored, now it throws an error.
321 Added parameterized types and did a pretty heavy refactoring of the
322 type constraint system.
324 Better framework extendability and better support for "making your own
327 =head1 Version 0.25 or before
329 Honestly, you shouldn't be using versions of Moose that are this old,
330 so many bug fixes and speed improvements have been made you would be
331 crazy to not upgrade.
333 Also, I am tired of going through the Changelog so I am stopping here,
334 if anyone would like to continue this please feel free.
338 Stevan Little E<lt>stevan@iinteractive.comE<gt>
340 =head1 COPYRIGHT AND LICENSE
342 Copyright 2009 by Infinity Interactive, Inc.
344 L<http://www.iinteractive.com>
346 This library is free software; you can redistribute it and/or modify
347 it under the same terms as Perl itself.