1 package Moose::Meta::Role::Application::ToRole;
7 use Scalar::Util 'blessed';
10 $VERSION = eval $VERSION;
11 our $AUTHORITY = 'cpan:STEVAN';
13 use base 'Moose::Meta::Role::Application';
16 my ($self, $role1, $role2) = @_;
17 $self->SUPER::apply($role1, $role2);
18 $role2->add_role($role1);
21 sub check_role_exclusions {
22 my ($self, $role1, $role2) = @_;
23 if ( $role2->excludes_role($role1->name) ) {
25 Moose->throw_error("Conflict detected: " . $role2->name . " excludes role '" . $role1->name . "'");
27 foreach my $excluded_role_name ($role1->get_excluded_roles_list) {
28 if ( $role2->does_role($excluded_role_name) ) {
30 Moose->throw_error("The class " . $role2->name . " does the excluded role '$excluded_role_name'");
32 $role2->add_excluded_roles($excluded_role_name);
36 sub check_required_methods {
37 my ($self, $role1, $role2) = @_;
38 foreach my $required_method ($role1->get_required_method_list) {
39 my $required_method_name = $required_method->name;
41 next if $self->is_aliased_method($required_method_name);
43 $role2->add_required_methods($required_method)
44 unless $role2->find_method_by_name($required_method_name);
48 sub check_required_attributes {
52 sub apply_attributes {
53 my ($self, $role1, $role2) = @_;
54 foreach my $attribute_name ($role1->get_attribute_list) {
55 # it if it has one already
56 if ($role2->has_attribute($attribute_name) &&
57 # make sure we haven't seen this one already too
58 $role2->get_attribute($attribute_name) != $role1->get_attribute($attribute_name)) {
61 Moose->throw_error("Role '" . $role1->name . "' has encountered an attribute conflict " .
62 "during composition. This is fatal error and cannot be disambiguated.");
65 $role2->add_attribute(
67 $role1->get_attribute($attribute_name)
74 my ($self, $role1, $role2) = @_;
75 foreach my $method_name ($role1->get_method_list) {
77 if ($self->is_method_aliased($method_name)) {
78 my $aliased_method_name = $self->get_method_aliases->{$method_name};
79 # it if it has one already
80 if ($role2->has_method($aliased_method_name) &&
81 # and if they are not the same thing ...
82 $role2->get_method($aliased_method_name)->body != $role1->get_method($method_name)->body) {
85 Moose->throw_error("Cannot create a method alias if a local method of the same name exists");
90 $role1->get_method($method_name)
93 if (!$role2->has_method($method_name)) {
94 $role2->add_required_methods($method_name)
95 unless $self->is_method_excluded($method_name);
101 next if $self->is_method_excluded($method_name);
103 # it if it has one already
104 if ($role2->has_method($method_name) &&
105 # and if they are not the same thing ...
106 $role2->get_method($method_name)->body != $role1->get_method($method_name)->body) {
107 # method conflicts between roles result
108 # in the method becoming a requirement
109 $role2->add_conflicting_method(
110 name => $method_name,
111 roles => [$role1->name, $role2->name],
115 # add it, although it could be overridden
118 $role1->get_method($method_name)
126 sub apply_override_method_modifiers {
127 my ($self, $role1, $role2) = @_;
128 foreach my $method_name ($role1->get_method_modifier_list('override')) {
129 # it if it has one already then ...
130 if ($role2->has_method($method_name)) {
131 # if it is being composed into another role
132 # we have a conflict here, because you cannot
133 # combine an overridden method with a locally
136 Moose->throw_error("Role '" . $role1->name . "' has encountered an 'override' method conflict " .
137 "during composition (A local method of the same name as been found). This " .
141 # if we are a role, we need to make sure
142 # we dont have a conflict with the role
143 # we are composing into
144 if ($role2->has_override_method_modifier($method_name) &&
145 $role2->get_override_method_modifier($method_name) != $role2->get_override_method_modifier($method_name)) {
148 Moose->throw_error("Role '" . $role1->name . "' has encountered an 'override' method conflict " .
149 "during composition (Two 'override' methods of the same name encountered). " .
150 "This is fatal error.");
153 # if there is no conflict,
154 # just add it to the role
155 $role2->add_override_method_modifier(
157 $role1->get_override_method_modifier($method_name)
164 sub apply_method_modifiers {
165 my ($self, $modifier_type, $role1, $role2) = @_;
166 my $add = "add_${modifier_type}_method_modifier";
167 my $get = "get_${modifier_type}_method_modifiers";
168 foreach my $method_name ($role1->get_method_modifier_list($modifier_type)) {
172 ) foreach $role1->$get($method_name);
185 Moose::Meta::Role::Application::ToRole - Compose a role into another role
199 =item B<check_role_exclusions>
201 =item B<check_required_methods>
203 =item B<check_required_attributes>
205 =item B<apply_attributes>
207 =item B<apply_methods>
209 =item B<apply_method_modifiers>
211 =item B<apply_override_method_modifiers>
217 All complex software has bugs lurking in it, and this module is no
218 exception. If you find a bug please either email me, or add the bug
223 Stevan Little E<lt>stevan@iinteractive.comE<gt>
225 =head1 COPYRIGHT AND LICENSE
227 Copyright 2006-2009 by Infinity Interactive, Inc.
229 L<http://www.iinteractive.com>
231 This library is free software; you can redistribute it and/or modify
232 it under the same terms as Perl itself.