support requires on Mouse::Role.

[gitmo/Mouse.git] / lib / Mouse / Meta / Role.pm

diff --git a/lib/Mouse/Meta/Role.pm b/lib/Mouse/Meta/Role.pm
index 181578a..ebb929f 100644 (file)
--- a/lib/Mouse/Meta/Role.pm
+++ b/lib/Mouse/Meta/Role.pm
@@ -2,7 +2,99 @@
 package Mouse::Meta::Role;
 use strict;
 use warnings;
+use Carp 'confess';
 
+do {
+    my %METACLASS_CACHE;
+
+    # because Mouse doesn't introspect existing classes, we're forced to
+    # only pay attention to other Mouse classes
+    sub _metaclass_cache {
+        my $class = shift;
+        my $name  = shift;
+        return $METACLASS_CACHE{$name};
+    }
+
+    sub initialize {
+        my $class = shift;
+        my $name  = shift;
+        $METACLASS_CACHE{$name} = $class->new(name => $name)
+            if !exists($METACLASS_CACHE{$name});
+        return $METACLASS_CACHE{$name};
+    }
+};
+
+sub new {
+    my $class = shift;
+    my %args  = @_;
+
+    $args{attributes}       ||= {};
+    $args{required_methods} ||= [];
+
+    bless \%args, $class;
+}
+
+sub name { $_[0]->{name} }
+
+sub add_required_methods {
+    my $self = shift;
+    my @methods = @_;
+    push @{$self->{required_methods}}, @methods;
+}
+
+sub add_attribute {
+    my $self = shift;
+    my $name = shift;
+    my $spec = shift;
+    $self->{attributes}->{$name} = $spec;
+}
+
+sub has_attribute { exists $_[0]->{attributes}->{$_[1]}  }
+sub get_attribute_list { keys %{ $_[0]->{attributes} } }
+sub get_attribute { $_[0]->{attributes}->{$_[1]} }
+
+sub apply {
+    my $self  = shift;
+    my $class = shift;
+
+    for my $name (@{$self->{required_methods}}) {
+        unless ($class->name->can($name)) {
+            confess "'@{[ $self->name ]}' requires the method '$name' to be implemented by '@{[ $class->name ]}'";
+        }
+    }
+
+    for my $name ($self->get_attribute_list) {
+        next if $class->has_attribute($name);
+        my $spec = $self->get_attribute($name);
+        Mouse::Meta::Attribute->create($class, $name, %$spec);
+    }
+
+    for my $modifier_type (qw/before after around/) {
+        my $add_method = "add_${modifier_type}_method_modifier";
+        my $modified = $self->{"${modifier_type}_method_modifiers"};
+
+        for my $method_name (keys %$modified) {
+            for my $code (@{ $modified->{$method_name} }) {
+                $class->$add_method($method_name => $code);
+            }
+        }
+    }
+}
+
+for my $modifier_type (qw/before after around/) {
+    no strict 'refs';
+    *{ __PACKAGE__ . '::' . "add_${modifier_type}_method_modifier" } = sub {
+        my ($self, $method_name, $method) = @_;
+
+        push @{ $self->{"${modifier_type}_method_modifiers"}->{$method_name} },
+            $method;
+    };
+
+    *{ __PACKAGE__ . '::' . "get_${modifier_type}_method_modifiers" } = sub {
+        my ($self, $method_name, $method) = @_;
+        @{ $self->{"${modifier_type}_method_modifiers"}->{$method_name} || [] }
+    };
+}
 
 1;