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<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
26 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
27 not we are in global destruction.
31 Type constraints no longer run coercions for a value that already matches the
32 constraint. This may affect some (arguably buggy) edge case coercions that
33 rely on side effects in the C<via> clause.
37 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
38 overriding the metaclass (without L<metaclass>). This works for classes
43 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
44 to make integration with non-Moose classes easier. It simply checks if
45 C<< $obj->can() >> a list of methods.
47 A number of methods (mostly inherited from L<Class::MOP>) have been
48 renamed with a leading underscore to indicate their internal-ness. The
49 old method names will still work for a while, but will warn that the
50 method has been renamed. In a few cases, the method will be removed
51 entirely in the future. This may affect MooseX authors who were using
56 Calling C<subtype> with a name as the only argument now throws an
57 exception. If you want an anonymous subtype do:
59 my $subtype = subtype as 'Foo';
61 This is related to the changes in version 0.71_01.
63 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
64 only usable as a class method. Previously, it worked as a class or
65 object method, with a different internal implementation for each
68 The internals of making a class immutable changed a lot in Class::MOP
69 0.78_02, and Moose's internals have changed along with it. The
70 external C<< $metaclass->make_immutable >> method still works the same
75 A mutable class accepted C<< Foo->new(undef) >> without complaint,
76 while an immutable class would blow up with an unhelpful error. Now,
77 in both cases we throw a helpful error instead.
79 This "feature" was originally added to allow for cases such as this:
87 return My::Class->new($args);
89 But we decided this is a bad idea and a little too magical, because it
90 can easily mask real errors.
92 =head1 Version 0.71_01
94 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
95 C<where>, C<message>) is now deprecated.
97 As a side effect, this meant we ended up using Perl prototypes on
98 C<as>, and code like this will no longer work:
100 use Moose::Util::TypeConstraints;
101 use Declare::Constraints::Simple -All;
103 subtype 'ArrayOfInts'
105 => IsArrayRef(IsInt);
107 Instead it must be changed to this:
112 where => IsArrayRef(IsInt)
116 If you want to maintain backwards compat with older versions of Moose,
117 you must explicitly test Moose's C<VERSION>:
119 if ( Moose->VERSION < 0.71_01 ) {
120 subtype 'ArrayOfInts'
122 => IsArrayRef(IsInt);
128 where => IsArrayRef(IsInt)
135 We no longer pass the meta-attribute object as a final argument to
136 triggers. This actually changed for inlined code a while back, but the
137 non-inlined version and the docs were still out of date.
139 If by some chance you actually used this feature, the workaround is
140 simple. You fetch the attribute object from out of the C<$self>
141 that is passed as the first argument to trigger, like so:
147 my ( $self, $value ) = @_;
148 my $attr = $self->meta->find_attribute_by_name('foo');
156 If you created a subtype and passed a parent that Moose didn't know
157 about, it simply ignored the parent. Now it automatically creates the
158 parent as a class type. This may not be what you want, but is less
161 You could declare a name with subtype such as "Foo!Bar". Moose would
162 accept this allowed, but if you used it in a parameterized type such
163 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
164 names created via the sugar functions, so that they can only contain
165 alphanumerics, ":", and ".".
169 Methods created via an attribute can now fulfill a C<requires>
170 declaration for a role. Honestly we don't know why Stevan didn't make
171 this work originally, he was just insane or something.
173 Stack traces from inlined code will now report the line and file as
174 being in your class, as opposed to in Moose guts.
176 =head1 Version 0.62_02
178 When a class does not provide all of a role's required methods, the
179 error thrown now mentions all of the missing methods, as opposed to
180 just the first missing method.
182 Moose will no longer inline a constructor for your class unless it
183 inherits its constructor from Moose::Object, and will warn when it
184 doesn't inline. If you want to force inlining anyway, pass
185 C<< "replace_constructor => 1 >> to C<make_immutable>.
187 If you want to get rid of the warning, pass C<< inline_constructor =>
192 Removed the (deprecated) C<make_immutable> keyword.
194 Removing an attribute from a class now also removes delegation
195 (C<handles>) methods installed for that attribute. This is correct
196 behavior, but if you were wrongly relying on it you might get bit.
200 Roles now add methods by calling C<add_method>, not
201 C<alias_method>. They make sure to always provide a method object,
202 which will be cloned internally. This means that it is now possible to
203 track the source of a method provided by a role, and even follow its
204 history through intermediate roles. This means that methods added by
205 a role now show up when looking at a class's method list/map.
207 Parameter and Union args are now sorted, this makes Int|Str the same
208 constraint as Str|Int. Also, incoming type constraint strings are
209 normalized to remove all whitespace differences. This is mostly for
210 internals and should not affect outside code.
212 L<Moose::Exporter> will no longer remove a subroutine that the
213 exporting package re-exports. Moose re-exports the Carp::confess
214 function, among others. The reasoning is that we cannot know whether
215 you have also explicitly imported those functions for your own use, so
216 we err on the safe side and always keep them.
220 C<Moose::init_meta> should now be called as a method.
222 New modules for extension writers, L<Moose::Exporter> and
223 L<Moose::Util::MetaRole>.
225 =head1 Version 0.55_01
227 Implemented metaclass traits (and wrote a recipe for it):
229 use Moose -traits => 'Foo'
231 This should make writing small Moose extensions a little
236 Fixed C<coerce> to accept anon types just like C<subtype> can.
239 coerce $some_anon_type => from 'Str' => via { ... };
243 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
247 Fixed how the C<< is => (ro|rw) >> works with custom defined
248 C<reader>, C<writer> and C<accessor> options. See the below table for
251 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
252 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
253 is => rw, accessor => _foo # turns into (accessor => _foo)
254 is => ro, accessor => _foo # error, accesor is rw
258 The C<before/around/after> method modifiers now support regexp
259 matching of method names. NOTE: this only works for classes, it is
260 currently not supported in roles, but, ... patches welcome.
262 The C<has> keyword for roles now accepts the same array ref form that
263 L<Moose>.pm does for classes.
265 A trigger on a read-only attribute is no longer an error, as it's
266 useful to trigger off of the constructor.
268 Subtypes of parameterizable types now are parameterizable types
273 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
274 not working correctly. It still kind of eats them, but so does vanilla
279 Inherited attributes may now be extended without restriction on the
280 type ('isa', 'does').
282 The entire set of Moose::Meta::TypeConstraint::* classes were
283 refactored in this release. If you were relying on their internals you
284 should test your code carefully.
288 Documenting the use of '+name' with attributes that come from recently
289 composed roles. It makes sense, people are using it, and so why not
290 just officially support it.
292 The C<< Moose::Meta::Class->create >> method now supports roles.
294 It is now possible to make anonymous enum types by passing C<enum> an
295 array reference instead of the C<< enum $name => @values >>.
299 Added the C<make_immutable> keyword as a shortcut to calling
300 C<make_immutable> on the meta object. This eventually got removed!
302 Made C<< init_arg => undef >> work in Moose. This means "do not accept
303 a constructor parameter for this attribute".
305 Type errors now use the provided message. Prior to this release they
310 Moose is now a postmodern object system :)
312 The Role system was completely refactored. It is 100% backwards
313 compat, but the internals were totally changed. If you relied on the
314 internals then you are advised to test carefully.
316 Added method exclusion and aliasing for Roles in this release.
318 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
321 Passing a list of values to an accessor (which is only expecting one
322 value) used to be silently ignored, now it throws an error.
326 Added parameterized types and did a pretty heavy refactoring of the
327 type constraint system.
329 Better framework extendability and better support for "making your own
332 =head1 Version 0.25 or before
334 Honestly, you shouldn't be using versions of Moose that are this old,
335 so many bug fixes and speed improvements have been made you would be
336 crazy to not upgrade.
338 Also, I am tired of going through the Changelog so I am stopping here,
339 if anyone would like to continue this please feel free.
343 Stevan Little E<lt>stevan@iinteractive.comE<gt>
345 =head1 COPYRIGHT AND LICENSE
347 Copyright 2009 by Infinity Interactive, Inc.
349 L<http://www.iinteractive.com>
351 This library is free software; you can redistribute it and/or modify
352 it under the same terms as Perl itself.