package Mouse::Role;
-use strict;
-use warnings;
-use base 'Exporter';
+use Mouse::Exporter; # enables strict and warnings
-use Carp 'confess', 'croak';
-use Scalar::Util 'blessed';
+our $VERSION = '0.91';
-use Mouse::Meta::Role;
-use Mouse::Util qw(load_class);
+use Carp ();
+use Scalar::Util ();
-our @EXPORT = qw(before after around super override inner augment has extends with requires excludes confess blessed);
-our %is_removable = map{ $_ => undef } @EXPORT;
-delete $is_removable{confess};
-delete $is_removable{blessed};
+use Mouse ();
-sub before {
+Mouse::Exporter->setup_import_methods(
+ as_is => [qw(
+ extends with
+ has
+ before after around
+ override super
+ augment inner
+
+ requires excludes
+ ),
+ \&Scalar::Util::blessed,
+ \&Carp::confess,
+ ],
+);
+
+
+sub extends {
+ Carp::croak "Roles do not support 'extends'";
+}
+
+sub with {
+ Mouse::Util::apply_all_roles(scalar(caller), @_);
+ return;
+}
+
+sub has {
my $meta = Mouse::Meta::Role->initialize(scalar caller);
+ my $name = shift;
+
+ $meta->throw_error(q{Usage: has 'name' => ( key => value, ... )})
+ if @_ % 2; # odd number of arguments
+ for my $n(ref($name) ? @{$name} : $name){
+ $meta->add_attribute($n => @_);
+ }
+ return;
+}
+
+sub before {
+ my $meta = Mouse::Meta::Role->initialize(scalar caller);
my $code = pop;
- for (@_) {
- $meta->add_before_method_modifier($_ => $code);
+ for my $name($meta->_collect_methods(@_)) {
+ $meta->add_before_method_modifier($name => $code);
}
+ return;
}
sub after {
my $meta = Mouse::Meta::Role->initialize(scalar caller);
-
my $code = pop;
- for (@_) {
- $meta->add_after_method_modifier($_ => $code);
+ for my $name($meta->_collect_methods(@_)) {
+ $meta->add_after_method_modifier($name => $code);
}
+ return;
}
sub around {
my $meta = Mouse::Meta::Role->initialize(scalar caller);
-
my $code = pop;
- for (@_) {
- $meta->add_around_method_modifier($_ => $code);
+ for my $name($meta->_collect_methods(@_)) {
+ $meta->add_around_method_modifier($name => $code);
}
+ return;
}
sub super {
- return unless $Mouse::SUPER_BODY;
+ return if !defined $Mouse::SUPER_BODY;
$Mouse::SUPER_BODY->(@Mouse::SUPER_ARGS);
}
sub override {
- my $classname = caller;
- my $meta = Mouse::Meta::Role->initialize($classname);
-
- my $name = shift;
- my $code = shift;
- my $fullname = "${classname}::${name}";
-
- defined &$fullname
- && confess "Cannot add an override of method '$fullname' " .
- "because there is a local version of '$fullname'";
-
- $meta->add_override_method_modifier($name => sub {
- local $Mouse::SUPER_PACKAGE = shift;
- local $Mouse::SUPER_BODY = shift;
- local @Mouse::SUPER_ARGS = @_;
-
- $code->(@_);
- });
+ # my($name, $code) = @_;
+ Mouse::Meta::Role->initialize(scalar caller)->add_override_method_modifier(@_);
+ return;
}
# We keep the same errors messages as Moose::Role emits, here.
sub inner {
- croak "Moose::Role cannot support 'inner'";
+ Carp::croak "Roles cannot support 'inner'";
}
sub augment {
- croak "Moose::Role cannot support 'augment'";
-}
-
-sub has {
- my $meta = Mouse::Meta::Role->initialize(scalar caller);
-
- my $name = shift;
- my %opts = @_;
-
- $meta->add_attribute($name => \%opts);
-}
-
-sub extends { confess "Roles do not support 'extends'" }
-
-sub with {
- my $meta = Mouse::Meta::Role->initialize(scalar caller);
- Mouse::Util::apply_all_roles($meta->name, @_);
+ Carp::croak "Roles cannot support 'augment'";
}
sub requires {
my $meta = Mouse::Meta::Role->initialize(scalar caller);
- Carp::croak "Must specify at least one method" unless @_;
+ $meta->throw_error("Must specify at least one method") unless @_;
$meta->add_required_methods(@_);
+ return;
}
-sub excludes { confess "Mouse::Role does not currently support 'excludes'" }
+sub excludes {
+ Mouse::Util::not_supported();
+}
-sub import {
- my $class = shift;
+sub init_meta{
+ shift;
+ my %args = @_;
- strict->import;
- warnings->import;
+ my $class = $args{for_class}
+ or Carp::confess("Cannot call init_meta without specifying a for_class");
- my $caller = caller;
+ my $metaclass = $args{metaclass} || 'Mouse::Meta::Role';
- # we should never export to main
- if ($caller eq 'main') {
- warn qq{$class does not export its sugar to the 'main' package.\n};
- return;
- }
+ my $meta = $metaclass->initialize($class);
- Mouse::Meta::Role->initialize($caller)->add_method(meta => sub {
- return Mouse::Meta::Role->initialize(ref($_[0]) || $_[0]);
+ $meta->add_method(meta => sub{
+ $metaclass->initialize(ref($_[0]) || $_[0]);
});
- Mouse::Role->export_to_level(1, @_);
-}
-
-sub unimport {
- my $caller = caller;
-
- my $stash = do{
- no strict 'refs';
- \%{$caller . '::'}
- };
-
- for my $keyword (@EXPORT) {
- my $code;
- if(exists $is_removable{$keyword}
- && ($code = $caller->can($keyword))
- && (Mouse::Util::get_code_info($code))[0] eq __PACKAGE__){
+ # make a role type for each Mouse role
+ Mouse::Util::TypeConstraints::role_type($class)
+ unless Mouse::Util::TypeConstraints::find_type_constraint($class);
- delete $stash->{$keyword};
- }
- }
- return;
+ return $meta;
}
1;
=head1 NAME
-Mouse::Role - define a role in Mouse
+Mouse::Role - The Mouse Role
+
+=head1 VERSION
+
+This document describes Mouse version 0.91
-=head1 KEYWORDS
+=head1 SYNOPSIS
-=head2 meta -> Mouse::Meta::Role
+ package Comparable;
+ use Mouse::Role; # the package is now a Mouse role
-Returns this role's metaclass instance.
+ # Declare methods that are required by this role
+ requires qw(compare);
-=head2 before (method|methods) => Code
+ # Define methods this role provides
+ sub equals {
+ my($self, $other) = @_;
+ return $self->compare($other) == 0;
+ }
-Sets up a "before" method modifier. See L<Moose/before> or
-L<Class::Method::Modifiers/before>.
+ # and later
+ package MyObject;
+ use Mouse;
+ with qw(Comparable); # Now MyObject can equals()
-=head2 after (method|methods) => Code
+ sub compare {
+ # ...
+ }
-Sets up an "after" method modifier. See L<Moose/after> or
-L<Class::Method::Modifiers/after>.
+ my $foo = MyObject->new();
+ my $bar = MyObject->new();
+ $obj->equals($bar); # yes, it is comparable
-=head2 around (method|methods) => Code
+=head1 DESCRIPTION
-Sets up an "around" method modifier. See L<Moose/around> or
-L<Class::Method::Modifiers/around>.
+This module declares the caller class to be a Mouse role.
-=over 4
+The concept of roles is documented in L<Moose::Manual::Roles>.
+This document serves as API documentation.
-=item B<super>
+=head1 EXPORTED FUNCTIONS
-Sets up the "super" keyword. See L<Moose/super>.
+Mouse::Role supports all of the functions that Mouse exports, but
+differs slightly in how some items are handled (see L</CAVEATS> below
+for details).
-=item B<override ($name, &sub)>
+Mouse::Role also offers two role-specific keywords:
-Sets up an "override" method modifier. See L<Moose/Role/override>.
+=head2 C<< requires(@method_names) >>
-=item B<inner>
+Roles can require that certain methods are implemented by any class which
+C<does> the role.
-This is not supported and emits an error. See L<Moose/Role>.
+Note that attribute accessors also count as methods for the purposes of
+satisfying the requirements of a role.
-=item B<augment ($name, &sub)>
+=head2 C<< excludes(@role_names) >>
-This is not supported and emits an error. See L<Moose/Role>.
+This is exported but not implemented in Mouse.
-=back
+=head1 IMPORT AND UNIMPORT
-=head2 has (name|names) => parameters
+=head2 import
-Sets up an attribute (or if passed an arrayref of names, multiple attributes) to
-this role. See L<Mouse/has>.
+Importing Mouse::Role will give you sugar. C<-traits> are also supported.
-=head2 confess error -> BOOM
+=head2 unimport
-L<Carp/confess> for your convenience.
+Please unimport (C<< no Mouse::Role >>) so that if someone calls one of the
+keywords (such as L</has>) it will break loudly instead breaking subtly.
-=head2 blessed value -> ClassName | undef
+=head1 CAVEATS
-L<Scalar::Util/blessed> for your convenience.
+Role support has only a few caveats:
-=head1 MISC
+=over
-=head2 import
+=item *
-Importing Mouse::Role will give you sugar.
+Roles cannot use the C<extends> keyword; it will throw an exception for now.
+The same is true of the C<augment> and C<inner> keywords (not sure those
+really make sense for roles). All other Mouse keywords will be I<deferred>
+so that they can be applied to the consuming class.
-=head2 unimport
+=item *
-Please unimport Mouse (C<no Mouse::Role>) so that if someone calls one of the
-keywords (such as L</has>) it will break loudly instead breaking subtly.
+Role composition does its best to B<not> be order-sensitive when it comes to
+conflict resolution and requirements detection. However, it is order-sensitive
+when it comes to method modifiers. All before/around/after modifiers are
+included whenever a role is composed into a class, and then applied in the order
+in which the roles are used. This also means that there is no conflict for
+before/around/after modifiers.
+
+In most cases, this will be a non-issue; however, it is something to keep in
+mind when using method modifiers in a role. You should never assume any
+ordering.
+
+=back
+
+=head1 SEE ALSO
+
+L<Mouse>
+
+L<Moose::Role>
+
+L<Moose::Manual::Roles>
+
+L<Moose::Spec::Role>
=cut