X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMouse.git;a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FRole.pm;h=6deb58c33e6b11120c068313ab044294a0b1e2bf;hp=92b39c17d66e411923d282ace5ce7c3b8b7bcc2d;hb=ea249879d28f5ce42afb95feeb7dcb6d37fcd241;hpb=83d0a1f4f1f73b914e26c1fb52626331de318c68

diff --git a/lib/Mouse/Meta/Role.pm b/lib/Mouse/Meta/Role.pm
index 92b39c1..6deb58c 100644
--- a/lib/Mouse/Meta/Role.pm
+++ b/lib/Mouse/Meta/Role.pm
@@ -1,39 +1,418 @@
-#!/usr/bin/env perl
 package Mouse::Meta::Role;
 use strict;
 use warnings;
 
-do {
-    my %METACLASS_CACHE;
+use Mouse::Util qw(not_supported english_list);
+use Mouse::Meta::Module;
 
-    # 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};
-    }
+use base qw(Mouse::Meta::Module);
 
-    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 method_metaclass(){ 'Mouse::Meta::Role::Method' } # required for get_method()
 
-sub new {
+sub _construct_meta {
     my $class = shift;
+
     my %args  = @_;
 
-    bless \%args, $class;
+    $args{methods}          ||= {};
+    $args{attributes}       ||= {};
+    $args{required_methods} ||= [];
+    $args{roles}            ||= [];
+
+#    return Mouse::Meta::Class->initialize($class)->new_object(%args)
+#        if $class ne __PACKAGE__;
+
+    return bless \%args, ref($class) || $class;
+}
+
+sub create_anon_role{
+    my $self = shift;
+    return $self->create(undef, @_);
+}
+
+sub is_anon_role{
+    return exists $_[0]->{anon_serial_id};
+}
+
+sub get_roles { $_[0]->{roles} }
+
+sub get_required_method_list{
+    return @{ $_[0]->{required_methods} };
+}
+
+sub add_required_methods {
+    my($self, @methods) = @_;
+    push @{$self->{required_methods}}, @methods;
+}
+
+sub requires_method {
+    my($self, $name) = @_;
+    return scalar( grep{ $_ eq $name } @{ $self->{required_methods} } ) != 0;
+}
+
+sub add_attribute {
+    my $self = shift;
+    my $name = shift;
+
+    $self->{attributes}->{$name} = (@_ == 1) ? $_[0] : { @_ };
 }
 
-sub name { $_[0]->{name} }
+sub _canonicalize_apply_args{
+    my($self, $applicant, %args) = @_;
+
+    if($applicant->isa('Mouse::Meta::Class')){
+        $args{_to} = 'class';
+    }
+    elsif($applicant->isa('Mouse::Meta::Role')){
+        $args{_to} = 'role';
+    }
+    else{
+        $args{_to} = 'instance';
+
+        not_supported 'Application::ToInstance';
+    }
+
+    if($args{alias} && !exists $args{-alias}){
+        $args{-alias} = $args{alias};
+    }
+    if($args{excludes} && !exists $args{-excludes}){
+        $args{-excludes} = $args{excludes};
+    }
+
+    if(my $excludes = $args{-excludes}){
+        $args{-excludes} = {}; # replace with a hash ref
+        if(ref $excludes){
+            %{$args{-excludes}} = (map{ $_ => undef } @{$excludes});
+        }
+        else{
+            $args{-excludes}{$excludes} = undef;
+        }
+    }
+
+    return \%args;
+}
+
+sub _check_required_methods{
+    my($role, $class, $args, @other_roles) = @_;
+
+    if($args->{_to} eq 'class'){
+        my $class_name = $class->name;
+        my $role_name  = $role->name;
+        my @missing;
+        foreach my $method_name(@{$role->{required_methods}}){
+            if(!$class_name->can($method_name)){
+                my $has_method      = 0;
+
+                foreach my $another_role_spec(@other_roles){
+                    my $another_role_name = $another_role_spec->[0];
+                    if($role_name ne $another_role_name && $another_role_name->can($method_name)){
+                        $has_method = 1;
+                        last;
+                    }
+                }
+
+                push @missing, $method_name if !$has_method;
+            }
+        }
+        if(@missing){
+            $class->throw_error("'$role_name' requires the "
+                . (@missing == 1 ? 'method' : 'methods')
+                . " "
+                . english_list(map{ sprintf q{'%s'}, $_ } @missing)
+                . " to be implemented by '$class_name'");
+        }
+    }
+    elsif($args->{_to} eq 'role'){
+        # apply role($role) to role($class)
+        foreach my $method_name($role->get_required_method_list){
+            next if $class->has_method($method_name); # already has it
+            $class->add_required_methods($method_name);
+        }
+    }
+
+    return;
+}
+
+sub _apply_methods{
+    my($role, $class, $args) = @_;
+
+    my $role_name  = $role->name;
+    my $class_name = $class->name;
+
+    my $alias    = $args->{-alias};
+    my $excludes = $args->{-excludes};
+
+    foreach my $method_name($role->get_method_list){
+        next if $method_name eq 'meta';
+
+        my $code = $role_name->can($method_name);
+
+        if(!exists $excludes->{$method_name}){
+            if(!$class->has_method($method_name)){
+                $class->add_method($method_name => $code);
+            }
+        }
+
+        if($alias && $alias->{$method_name}){
+            my $dstname = $alias->{$method_name};
+
+            my $dstcode = do{ no strict 'refs'; *{$class_name . '::' . $dstname}{CODE} };
+
+            if(defined($dstcode) && $dstcode != $code){
+                $class->throw_error("Cannot create a method alias if a local method of the same name exists");
+            }
+            else{
+                $class->add_method($dstname => $code);
+            }
+        }
+    }
+
+    return;
+}
+
+sub _apply_attributes{
+    my($role, $class, $args) = @_;
+
+    if ($args->{_to} eq 'class') {
+        # apply role to class
+        for my $attr_name ($role->get_attribute_list) {
+            next if $class->has_attribute($attr_name);
+
+            my $spec = $role->get_attribute($attr_name);
+
+            $class->add_attribute($attr_name => %{$spec});
+        }
+    }
+    elsif($args->{_to} eq 'role'){
+        # apply role to role
+        for my $attr_name ($role->get_attribute_list) {
+            next if $class->has_attribute($attr_name);
+
+            my $spec = $role->get_attribute($attr_name);
+            $class->add_attribute($attr_name => $spec);
+        }
+    }
+
+    return;
+}
+
+sub _apply_modifiers{
+    my($role, $class, $args) = @_;
+
+    for my $modifier_type (qw/override before around after/) {
+        my $add_modifier = "add_${modifier_type}_method_modifier";
+        my $modifiers    = $role->{"${modifier_type}_method_modifiers"};
+
+        while(my($method_name, $modifier_codes) = each %{$modifiers}){
+            foreach my $code(ref($modifier_codes) eq 'ARRAY' ? @{$modifier_codes} : $modifier_codes){
+                $class->$add_modifier($method_name => $code);
+            }
+        }
+    }
+    return;
+}
+
+sub _append_roles{
+    my($role, $class, $args) = @_;
+
+    my $roles = ($args->{_to} eq 'class') ? $class->roles : $class->get_roles;
+
+    foreach my $r($role, @{$role->get_roles}){
+        if(!$class->does_role($r->name)){
+            push @{$roles}, $r;
+        }
+    }
+    return;
+}
+
+# Moose uses Application::ToInstance, Application::ToClass, Application::ToRole
+sub apply {
+    my $self      = shift;
+    my $applicant = shift;
+
+    my $args = $self->_canonicalize_apply_args($applicant, @_);
+
+    $self->_check_required_methods($applicant, $args);
+    $self->_apply_methods($applicant, $args);
+    $self->_apply_attributes($applicant, $args);
+    $self->_apply_modifiers($applicant, $args);
+    $self->_append_roles($applicant, $args);
+    return;
+}
+
+sub combine_apply {
+    my(undef, $class, @roles) = @_;
+
+    if($class->isa('Mouse::Object')){
+        not_supported 'Application::ToInstance';
+    }
+
+    # check conflicting
+    my %method_provided;
+    my @method_conflicts;
+    my %attr_provided;
+    my %override_provided;
+
+    foreach my $role_spec (@roles) {
+        my $role      = $role_spec->[0]->meta;
+        my $role_name = $role->name;
+
+        # methods
+        foreach my $method_name($role->get_method_list){
+            next if $class->has_method($method_name); # manually resolved
+
+            my $code = do{ no strict 'refs'; \&{ $role_name . '::' . $method_name } };
+
+            my $c = $method_provided{$method_name};
+
+            if($c && $c->[0] != $code){
+                push @{$c}, $role;
+                push @method_conflicts, $c;
+            }
+            else{
+                $method_provided{$method_name} = [$code, $method_name, $role];
+            }
+        }
+
+        # attributes
+        foreach my $attr_name($role->get_attribute_list){
+            my $attr = $role->get_attribute($attr_name);
+            my $c    = $attr_provided{$attr_name};
+            if($c && $c != $attr){
+                $class->throw_error("We have encountered an attribute conflict with '$attr_name' "
+                                   . "during composition. This is fatal error and cannot be disambiguated.")
+            }
+            else{
+                $attr_provided{$attr_name} = $attr;
+            }
+        }
+
+        # override modifiers
+        foreach my $method_name($role->get_method_modifier_list('override')){
+            my $override = $role->get_override_method_modifier($method_name);
+            my $c        = $override_provided{$method_name};
+            if($c && $c != $override){
+                $class->throw_error( "We have encountered an 'override' method conflict with '$method_name' during "
+                                   . "composition (Two 'override' methods of the same name encountered). "
+                                   . "This is fatal error.")
+            }
+            else{
+                $override_provided{$method_name} = $override;
+            }
+        }
+    }
+    if(@method_conflicts){
+        my $error;
+
+        if(@method_conflicts == 1){
+            my($code, $method_name, @roles) = @{$method_conflicts[0]};
+            $class->throw_error(
+                sprintf q{Due to a method name conflict in roles %s, the method '%s' must be implemented or excluded by '%s'},
+                    english_list(map{ sprintf q{'%s'}, $_->name } @roles), $method_name, $class->name
+            );
+        }
+        else{
+            @method_conflicts = sort { $a->[0] cmp $b->[0] } @method_conflicts; # to avoid hash-ordering bugs
+            my $methods = english_list(map{ sprintf q{'%s'}, $_->[1] } @method_conflicts);
+            my $roles   = english_list(
+                map{ sprintf q{'%s'}, $_->name }
+                map{ my($code, $method_name, @roles) = @{$_}; @roles } @method_conflicts
+            );
+
+            $class->throw_error(
+                sprintf q{Due to method name conflicts in roles %s, the methods %s must be implemented or excluded by '%s'},
+                    $roles, $methods, $class->name
+            );
+        }
+    }
+
+    foreach my $role_spec (@roles) {
+        my($role_name, $args) = @{$role_spec};
+
+        my $role = $role_name->meta;
+
+        $args = $role->_canonicalize_apply_args($class, %{$args});
+
+        $role->_check_required_methods($class, $args, @roles);
+        $role->_apply_methods($class, $args);
+        $role->_apply_attributes($class, $args);
+        $role->_apply_modifiers($class, $args);
+        $role->_append_roles($class, $args);
+    }
+    return;
+}
+
+for my $modifier_type (qw/before after around/) {
+
+    my $modifier = "${modifier_type}_method_modifiers";
+    my $add_method_modifier =  sub {
+        my ($self, $method_name, $method) = @_;
+
+        push @{ $self->{$modifier}->{$method_name} ||= [] }, $method;
+        return;
+    };
+    my $has_method_modifiers = sub{
+        my($self, $method_name) = @_;
+        my $m = $self->{$modifier}->{$method_name};
+        return $m && @{$m} != 0;
+    };
+    my $get_method_modifiers = sub {
+        my ($self, $method_name) = @_;
+        return @{ $self->{$modifier}->{$method_name} ||= [] }
+    };
+
+    no strict 'refs';
+    *{ 'add_' . $modifier_type . '_method_modifier'  } = $add_method_modifier;
+    *{ 'has_' . $modifier_type . '_method_modifiers' } = $has_method_modifiers;
+    *{ 'get_' . $modifier_type . '_method_modifiers' } = $get_method_modifiers;
+}
+
+sub add_override_method_modifier{
+    my($self, $method_name, $method) = @_;
+
+    if($self->has_method($method_name)){
+        # This error happens in the override keyword or during role composition,
+        # so I added a message, "A local method of ...", only for compatibility (gfx)
+        $self->throw_error("Cannot add an override of method '$method_name' "
+                   . "because there is a local version of '$method_name'"
+                   . "(A local method of the same name as been found)");
+    }
+
+    $self->{override_method_modifiers}->{$method_name} = $method;
+}
+
+sub has_override_method_modifier {
+    my ($self, $method_name) = @_;
+    return exists $self->{override_method_modifiers}->{$method_name};
+}
+
+sub get_override_method_modifier {
+    my ($self, $method_name) = @_;
+    return $self->{override_method_modifiers}->{$method_name};
+}
+
+sub get_method_modifier_list {
+    my($self, $modifier_type) = @_;
+
+    return keys %{ $self->{$modifier_type . '_method_modifiers'} };
+}
+
+# This is currently not passing all the Moose tests.
+sub does_role {
+    my ($self, $role_name) = @_;
+
+    (defined $role_name)
+        || $self->throw_error("You must supply a role name to look for");
+
+    # if we are it,.. then return true
+    return 1 if $role_name eq $self->name;
+    # otherwise.. check our children
+    for my $role (@{ $self->get_roles }) {
+        return 1 if $role->does_role($role_name);
+    }
+    return 0;
+}
 
-sub has_attribute { exists $_[0]->{attributes}->{$_[1]}  }
-sub add_attribute { $_[0]->{attributes}->{$_[1]} = $_[2] }
 
 1;