Moose::Manual::Delta(3pm)

NAME

Moose::Manual::Delta - Important Changes in Moose

DESCRIPTION

This documents any important or noteworthy changes in Moose, with a
focus on backwards. This does duplicate data from the Changes file, but aims to provide more details and when possible workarounds.

Besides helping keep up with changes, you can also use this document
for finding the lowest version of Moose that supported a given feature. If you encounter a problem and have a solution but don't see it
documented here, or think we missed an important feature, please send
us a patch.
1.09
All deprecated features now warn: Previously, deprecation mostly consisted of simply saying "X is
deprecated" in the Changes file. We were not very consistent about actually warning. Now, all deprecated features still present in
Moose actually give a warning. The warning is issued once per
calling package. See Moose::Deprecated for more details.
You cannot pass "coerce => 1" unless the attribute's type constraint has a coercion: Previously, this was accepted, and it sort of worked, except that
if you attempted to set the attribute after the object was created, you would get a runtime error.; Now you will get an error when you attempt to define the attribute.
"no Moose", "no Moose::Role", and "no Moose::Exporter" no longer unimport strict and warnings: This change was made in 1.05, and has now been reverted. We don't
know if the user has explicitly loaded strict or warnings on their own, and unimporting them is just broken in that case.
Reversed logic when defining which options can be changed: Moose::Meta::Attribute now allows all options to be changed in an
overridden attribute. The previous behaviour required each option
to be whitelisted using the "legal_options_for_inheritance" method. This method has been removed, and there is a new method,
"illegal_options_for_inheritance", which can now be used to prevent certain options from being changeable.; In addition, we only throw an error if the illegal option is
actually changed. If the superclass didn't specify this option at
all when defining the attribute, the subclass version can still add it as an option.; Example of overriding this in an attribute trait:

package Bar::Meta::Attribute;
use Moose::Role;

has 'my_illegal_option' => (
isa => 'CodeRef',
is => 'rw',

);

around illegal_options_for_inheritance => sub {

return ( shift->(@_), qw/my_illegal_option/ );

};
1.05
"BUILD" in Moose::Object methods are now called when calling "new_object": Previously, "BUILD" methods would only be called from
"Moose::Object::new", but now they are also called when
constructing an object via "Moose::Meta::Class::new_object".
"BUILD" methods are an inherent part of the object construction
process, and this should make "$meta->new_object" actually usable
without forcing people to use "$meta->name->new".
"no Moose", "no Moose::Role", and "no Moose::Exporter" now unimport strict and warnings: In the interest of having "no Moose" clean up everything that "use Moose" does in the calling scope, "no Moose" (as well as all other Moose::Exporter-using modules) now unimports strict and warnings.
Metaclass compatibility checking and fixing should be much more robust: The metaclass compatibility checking and fixing algorithms have
been completely rewritten, in both Class::MOP and Moose. This
should resolve many confusing errors when dealing with non-Moose
inheritance and with custom metaclasses for things like attributes, constructors, etc. For correct code, the only thing that should
require a change is that custom error metaclasses must now inherit from Moose::Error::Default.
1.02
Moose::Meta::TypeConstraint::Class is_subtype_of behavior: Earlier versions of is_subtype_of would incorrectly return true
when called with itself, its own TC name or its class name as an
argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This behavior
was a caused by "isa" being checked before the class name. The old behavior can be accessed with is_type_of
1.00
Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default: Earlier versions of Moose::Meta::Attribute::Native::Trait::Code
created read-only accessors for the attributes it's been applied
to, even if you didn't ask for it with "is => 'ro'". This incorrect behaviour has now been fixed.
0.95
Moose::Util add_method_modifier behavior: add_method_modifier (and subsequently the sugar functions
Moose::before, Moose::after, and Moose::around) can now accept
arrayrefs, with the same behavior as lists. Types other than
arrayref and regexp result in an error.
0.93_01 and 0.94
Moose::Util::MetaRole API has changed: The "apply_metaclass_roles" function is now called
"apply_metaroles". The way arguments are supplied has been changed to force you to distinguish between metaroles applied to
Moose::Meta::Class (and helpers) versus Moose::Meta::Role.; The old API still works, but will warn in a future release, and
eventually be removed.
Moose::Meta::Role has real attributes: The attributes returned by Moose::Meta::Role are now instances of
the Moose::Meta::Role::Attribute class, instead of bare hash
references.
"no Moose" now removes "blessed" and "confess": Moose is now smart enough to know exactly what it exported, even
when it re-exports functions from other packages. When you unimport Moose, it will remove these functions from your namespace unless
you also imported them directly from their respective packages.; If you have a "no Moose" in your code before you call "blessed" or "confess", your code will break. You can either move the "no Moose" call later in your code, or explicitly import the relevant
functions from the packages that provide them.
Moose::Exporter is smarter about unimporting re-exports: The change above comes from a general improvement to
Moose::Exporter. It will now unimport any function it exports, even if that function is a re-export from another package.
Attributes in roles can no longer override class attributes with "+foo": Previously, this worked more or less accidentally, because role
attributes weren't objects. This was never documented, but a few
MooseX modules took advantage of this.
The composition_class_roles attribute in Moose::Meta::Role is now a method: This was done to make it possible for roles to alter the the list
of composition class roles by applying a method modifiers.
Previously, this was an attribute and MooseX modules override it.
Since that no longer works, this was made a method.; This should be an attribute, so this may switch back to being an attribute in the future if we can figure out how to make this work.
0.93
Calling $object->new() is no longer deprecated: We decided to undeprecate this. Now it just works.
Both "get_method_map" and "get_attribute_map" is deprecated: These metaclass methods were never meant to be public, and they are both now deprecated. The work around if you still need the
functionality they provided is to iterate over the list of names
manually.

my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;; This was actually a change in Class::MOP, but this version of Moose requires a version of Class::MOP that includes said change.
0.90
Added Native delegation for Code refs: See Moose::Meta::Attribute::Native::Trait::Code for details.
Calling $object->new() is deprecated: Moose has long supported this, but it's never really been
documented, and we don't think this is a good practice. If you want to construct an object from an existing object, you should provide some sort of alternate constructor like "$object->clone".; Calling "$object->new" now issues a warning, and will be an error
in a future release.
Moose no longer warns if you call "make_immutable" for a class with mutable ancestors: While in theory this is a good thing to warn about, we found so
many exceptions to this that doing this properly became quite
problematic.

Version 0.89_02

New Native delegation methods from List::Util and List::MoreUtils: In particular, we now have "reduce", "shuffle", "uniq", and
"natatime".
The Moose::Exporter with_caller feature is now deprecated: Use "with_meta" instead. The "with_caller" option will start
warning in a future release.
Moose now warns if you call "make_immutable" for a class with mutable ancestors: This is dangerous because modifying a class after a subclass has
been immutabilized will lead to incorrect results in the subclass, due to inlining, caching, etc. This occasionally happens
accidentally, when a class loads one of its subclasses in the
middle of its class definition, so pointing out that this may cause issues should be helpful. Metaclasses (classes that inherit from
Class::MOP::Object) are currently exempt from this check, since at the moment we aren't very consistent about which metaclasses we
immutabilize.
"enum" and "duck_type" now take arrayrefs for all forms: Previously, calling these functions with a list would take the
first element of the list as the type constraint name, and use the remainder as the enum values or method names. This makes the
interface inconsistent with the anon-type forms of these functions (which must take an arrayref), and a free-form list where the first value is sometimes special is hard to validate (and harder to give reasonable error messages for). These functions have been changed
to take arrayrefs in all their forms - so, "enum 'My::Type' =>
[qw(foo bar)]" is now the preferred way to create an enum type
constraint. The old syntax still works for now, but it will
hopefully be deprecated and removed in a future release.

Version 0.89_01

Moose::Meta::Attribute::Native has been moved into the Moose core from MooseX::AttributeHelpers. Major changes include:

"traits", not "metaclass": Method providers are only available via traits.
"handles", not "provides" or "curries": The "provides" syntax was like core Moose "handles => HASHREF"
syntax, but with the keys and values reversed. This was confusing, and AttributeHelpers now uses "handles => HASHREF" in a way that
should be intuitive to anyone already familiar with how it is used for other attributes.; The "curries" functionality provided by AttributeHelpers has been
generalized to apply to all cases of "handles => HASHREF", though
not every piece of functionality has been ported (currying with a
CODEREF is not supported).
"empty" is now "is_empty", and means empty, not non-empty: Previously, the "empty" method provided by Arrays and Hashes
returned true if the attribute was not empty (no elements). Now it returns true if the attribute is empty. It was also renamed to "is_empty", to reflect this.
"find" was renamed to "first", and "first" and "last" were removed: List::Util refers to the functionality that we used to provide
under "find" as first, so that will likely be more familiar (and
will fit in better if we decide to add more List::Util functions). "first" and "last" were removed, since their functionality is
easily duplicated with curries of "get".
Helpers that take a coderef of one argument now use $_: Subroutines passed as the first argument to "first", "map", and
"grep" now receive their argument in $_ rather than as a parameter to the subroutine. Helpers that take a coderef of two or more
arguments remain using the argument list (there are technical
limitations to using $a and $b like "sort" does).; See Moose::Meta::Attribute::Native for the new documentation.
The "alias" and "excludes" role parameters have been renamed to "-alias" and "-excludes". The old names still work, but new code should use the new names, and eventually the old ones will be deprecated and removed.

Version 0.89

"use Moose -metaclass => 'Foo'" now does alias resolution, just like
"-traits" (and the "metaclass" and "traits" options to "has").

Added two functions "meta_class_alias" and "meta_attribute_alias" to Moose::Util, to simplify aliasing metaclasses and metatraits. This is a wrapper around the old: package Moose::Meta::Class::Custom::Trait::FooTrait;
sub register_implementation { 'My::Meta::Trait' }
way of doing this.

Version 0.84

When an attribute generates no accessors, we now warn. This is to help users who forget the "is" option. If you really do not want any accessors, you can use "is => 'bare'". You can maintain back compat with older versions of Moose by using something like:: ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
When an accessor overwrites an existing method, we now warn. To work around this warning (if you really must have this behavior), you can explicitly remove the method before creating it as an accessor:: sub foo {}; __PACKAGE__->meta->remove_method('foo');; has foo => (
is => 'ro',; );
When an unknown option is passed to "has", we now warn. You can silence the warning by fixing your code. :)
The "Role" type has been deprecated. On its own, it was useless, since it just checked "$object->can('does')". If you were using it as a parent type, just call "role_type('Role::Name')" to create an appropriate type instead.

Version 0.78

"use Moose::Exporter;" now imports "strict" and "warnings" into
packages that use it.

Version 0.77

"DEMOLISHALL" and "DEMOLISH" now receive an argument indicating whether or not we are in global destruction.

Version 0.76

Type constraints no longer run coercions for a value that already
matches the constraint. This may affect some (arguably buggy) edge
case coercions that rely on side effects in the "via" clause.

Version 0.75

Moose::Exporter now accepts the "-metaclass" option for easily
overriding the metaclass (without metaclass). This works for classes
and roles.

Version 0.74

Added a "duck_type" sugar function to Moose::Util::TypeConstraints to
make integration with non-Moose classes easier. It simply checks if
"$obj->can()" a list of methods.

A number of methods (mostly inherited from Class::MOP) have been
renamed with a leading underscore to indicate their internal-ness. The old method names will still work for a while, but will warn that the
method has been renamed. In a few cases, the method will be removed
entirely in the future. This may affect MooseX authors who were using
these methods.

Version 0.73

Calling "subtype" with a name as the only argument now throws an exception. If you want an anonymous subtype do:: my $subtype = subtype as 'Foo';
This is related to the changes in version 0.71_01.
The "is_needed" method in Moose::Meta::Method::Destructor is now only usable as a class method. Previously, it worked as a class or object method, with a different internal implementation for each version.
The internals of making a class immutable changed a lot in Class::MOP 0.78_02, and Moose's internals have changed along with it. The external "$metaclass->make_immutable" method still works the same way.

Version 0.72

A mutable class accepted "Foo->new(undef)" without complaint, while an immutable class would blow up with an unhelpful error. Now, in both
cases we throw a helpful error instead.

This "feature" was originally added to allow for cases such as this:: my $args;; if ( something() ) {
$args = {...};; }; return My::Class->new($args);
But we decided this is a bad idea and a little too magical, because it can easily mask real errors.

Version 0.71_01

Calling "type" or "subtype" without the sugar helpers ("as", "where",
"message") is now deprecated.

As a side effect, this meant we ended up using Perl prototypes on "as", and code like this will no longer work:: use Moose::Util::TypeConstraints;
use Declare::Constraints::Simple -All;; subtype 'ArrayOfInts'
=> as 'ArrayRef'
=> IsArrayRef(IsInt);; Instead it must be changed to this:

subtype(
'ArrayOfInts' => {
as => 'ArrayRef',
where => IsArrayRef(IsInt)

}

);; If you want to maintain backwards compat with older versions of Moose, you must explicitly test Moose's "VERSION":

if ( Moose->VERSION < 0.71_01 ) {
subtype 'ArrayOfInts'
=> as 'ArrayRef'
=> IsArrayRef(IsInt);

}
else {

subtype(
'ArrayOfInts' => {
as => 'ArrayRef',
where => IsArrayRef(IsInt)

}

);

}

Version 0.70

We no longer pass the meta-attribute object as a final argument to
triggers. This actually changed for inlined code a while back, but the non-inlined version and the docs were still out of date.

If by some chance you actually used this feature, the workaround is simple. You fetch the attribute object from out of the $self that is passed as the first argument to trigger, like so:: has 'foo' => (
is => 'ro',
isa => 'Any',
trigger => sub {
my ( $self, $value ) = @_;
my $attr = $self->meta->find_attribute_by_name('foo');

# ...

}; );

Version 0.66

If you created a subtype and passed a parent that Moose didn't know
about, it simply ignored the parent. Now it automatically creates the
parent as a class type. This may not be what you want, but is less
broken than before.

You could declare a name with subtype such as "Foo!Bar". Moose would
accept this allowed, but if you used it in a parameterized type such as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on names
created via the sugar functions, so that they can only contain
alphanumerics, ":", and ".".

Version 0.65

Methods created via an attribute can now fulfill a "requires"
declaration for a role. Honestly we don't know why Stevan didn't make
this work originally, he was just insane or something.

Stack traces from inlined code will now report the line and file as
being in your class, as opposed to in Moose guts.

Version 0.62_02

When a class does not provide all of a role's required methods, the
error thrown now mentions all of the missing methods, as opposed to
just the first missing method.

Moose will no longer inline a constructor for your class unless it
inherits its constructor from Moose::Object, and will warn when it
doesn't inline. If you want to force inlining anyway, pass
"replace_constructor => 1" to "make_immutable".

If you want to get rid of the warning, pass "inline_constructor => 0".

Version 0.62

Removed the (deprecated) "make_immutable" keyword.

Removing an attribute from a class now also removes delegation
("handles") methods installed for that attribute. This is correct
behavior, but if you were wrongly relying on it you might get bit.

Version 0.58

Roles now add methods by calling "add_method", not "alias_method". They make sure to always provide a method object, which will be cloned
internally. This means that it is now possible to track the source of a method provided by a role, and even follow its history through
intermediate roles. This means that methods added by a role now show
up when looking at a class's method list/map.

Parameter and Union args are now sorted, this makes Int|Str the same
constraint as Str|Int. Also, incoming type constraint strings are
normalized to remove all whitespace differences. This is mostly for
internals and should not affect outside code.

Moose::Exporter will no longer remove a subroutine that the exporting
package re-exports. Moose re-exports the Carp::confess function, among others. The reasoning is that we cannot know whether you have also
explicitly imported those functions for your own use, so we err on the safe side and always keep them.

Version 0.56

"Moose::init_meta" should now be called as a method.

New modules for extension writers, Moose::Exporter and
Moose::Util::MetaRole.

Version 0.55_01

Implemented metaclass traits (and wrote a recipe for it):: use Moose -traits => 'Foo'
This should make writing small Moose extensions a little easier.

Version 0.55

Fixed "coerce" to accept anon types just like "subtype" can. So that you can do:: coerce $some_anon_type => from 'Str' => via { ... };

Version 0.51

Added "BUILDARGS", a new step in "Moose::Object->new()".

Version 0.49

Fixed how the "is => (ro|rw)" works with custom defined "reader", "writer" and "accessor" options. See the below table for details:: is => ro, writer => _foo # turns into (reader => foo, writer => _foo) is => rw, writer => _foo # turns into (reader => foo, writer => _foo) is => rw, accessor => _foo # turns into (accessor => _foo)
is => ro, accessor => _foo # error, accesor is rw

Version 0.45

The "before/around/after" method modifiers now support regexp matching of method names. NOTE: this only works for classes, it is currently not supported in roles, but, ... patches welcome.

The "has" keyword for roles now accepts the same array ref form that
Moose.pm does for classes.

A trigger on a read-only attribute is no longer an error, as it's
useful to trigger off of the constructor.

Subtypes of parameterizable types now are parameterizable types
themselves.

Version 0.44

Fixed issue where "DEMOLISHALL" was eating the value in $@, and so not working correctly. It still kind of eats them, but so does vanilla
perl.

Version 0.41

Inherited attributes may now be extended without restriction on the
type ('isa', 'does').

The entire set of Moose::Meta::TypeConstraint::* classes were
refactored in this release. If you were relying on their internals you should test your code carefully.

Version 0.40

Documenting the use of '+name' with attributes that come from recently composed roles. It makes sense, people are using it, and so why not
just officially support it.

The "Moose::Meta::Class->create" method now supports roles.

It is now possible to make anonymous enum types by passing "enum" an
array reference instead of the "enum $name => @values".

Version 0.37

Added the "make_immutable" keyword as a shortcut to calling
"make_immutable" on the meta object. This eventually got removed!

Made "init_arg => undef" work in Moose. This means "do not accept a
constructor parameter for this attribute".

Type errors now use the provided message. Prior to this release they
didn't.

Version 0.34

Moose is now a postmodern object system :)

The Role system was completely refactored. It is 100% backwards compat, but the internals were totally changed. If you relied on the internals then you are advised to test carefully.

Added method exclusion and aliasing for Roles in this release.

Added the Moose::Util::TypeConstraints::OptimizedConstraints module.

Passing a list of values to an accessor (which is only expecting one
value) used to be silently ignored, now it throws an error.

Version 0.26

Added parameterized types and did a pretty heavy refactoring of the
type constraint system.

Better framework extendability and better support for "making your own Moose".

Version 0.25 or before

Honestly, you shouldn't be using versions of Moose that are this old,
so many bug fixes and speed improvements have been made you would be
crazy to not upgrade.

Also, I am tired of going through the Changelog so I am stopping here, if anyone would like to continue this please feel free.

AUTHOR

Stevan Little <stevan@iinteractive.com>

COPYRIGHT AND LICENSE

<http://www.iinteractive.com>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

docs.sk

comprehensive documentation repository

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