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