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 Moose->throw_error("Conflict detected: " . $role2->name . " excludes role '" . $role1->name . "'")
24 if $role2->excludes_role($role1->name);
25 foreach my $excluded_role_name ($role1->get_excluded_roles_list) {
26 Moose->throw_error("The class " . $role2->name . " does the excluded role '$excluded_role_name'")
27 if $role2->does_role($excluded_role_name);
28 $role2->add_excluded_roles($excluded_role_name);
32 sub check_required_methods {
33 my ($self, $role1, $role2) = @_;
34 foreach my $required_method_name ($role1->get_required_method_list) {
36 next if $self->is_aliased_method($required_method_name);
38 $role2->add_required_methods($required_method_name)
39 unless $role2->find_method_by_name($required_method_name);
43 sub check_required_attributes {
47 sub apply_attributes {
48 my ($self, $role1, $role2) = @_;
49 foreach my $attribute_name ($role1->get_attribute_list) {
50 # it if it has one already
51 if ($role2->has_attribute($attribute_name) &&
52 # make sure we haven't seen this one already too
53 $role2->get_attribute($attribute_name) != $role1->get_attribute($attribute_name)) {
54 Moose->throw_error("Role '" . $role1->name . "' has encountered an attribute conflict " .
55 "during composition. This is fatal error and cannot be disambiguated.");
58 $role2->add_attribute(
60 $role1->get_attribute($attribute_name)
67 my ($self, $role1, $role2) = @_;
68 foreach my $method_name ($role1->get_method_list) {
70 next if $self->is_method_excluded($method_name);
72 if ($self->is_method_aliased($method_name)) {
73 my $aliased_method_name = $self->get_method_aliases->{$method_name};
74 # it if it has one already
75 if ($role2->has_method($aliased_method_name) &&
76 # and if they are not the same thing ...
77 $role2->get_method($aliased_method_name)->body != $role1->get_method($method_name)->body) {
78 Moose->throw_error("Cannot create a method alias if a local method of the same name exists");
83 $role1->get_method($method_name)
86 if (!$role2->has_method($method_name)) {
87 $role2->add_required_methods($method_name);
93 # it if it has one already
94 if ($role2->has_method($method_name) &&
95 # and if they are not the same thing ...
96 $role2->get_method($method_name)->body != $role1->get_method($method_name)->body) {
97 # method conflicts between roles result
98 # in the method becoming a requirement
99 $role2->add_required_methods($method_name);
102 # add it, although it could be overriden
105 $role1->get_method($method_name)
113 sub apply_override_method_modifiers {
114 my ($self, $role1, $role2) = @_;
115 foreach my $method_name ($role1->get_method_modifier_list('override')) {
116 # it if it has one already then ...
117 if ($role2->has_method($method_name)) {
118 # if it is being composed into another role
119 # we have a conflict here, because you cannot
120 # combine an overriden method with a locally
122 Moose->throw_error("Role '" . $role1->name . "' has encountered an 'override' method conflict " .
123 "during composition (A local method of the same name as been found). This " .
127 # if we are a role, we need to make sure
128 # we dont have a conflict with the role
129 # we are composing into
130 if ($role2->has_override_method_modifier($method_name) &&
131 $role2->get_override_method_modifier($method_name) != $role2->get_override_method_modifier($method_name)) {
132 Moose->throw_error("Role '" . $role1->name . "' has encountered an 'override' method conflict " .
133 "during composition (Two 'override' methods of the same name encountered). " .
134 "This is fatal error.");
137 # if there is no conflict,
138 # just add it to the role
139 $role2->add_override_method_modifier(
141 $role1->get_override_method_modifier($method_name)
148 sub apply_method_modifiers {
149 my ($self, $modifier_type, $role1, $role2) = @_;
150 my $add = "add_${modifier_type}_method_modifier";
151 my $get = "get_${modifier_type}_method_modifiers";
152 foreach my $method_name ($role1->get_method_modifier_list($modifier_type)) {
156 ) foreach $role1->$get($method_name);
169 Moose::Meta::Role::Application::ToRole - Compose a role into another role
183 =item B<check_role_exclusions>
185 =item B<check_required_methods>
187 =item B<check_required_attributes>
189 =item B<apply_attributes>
191 =item B<apply_methods>
193 =item B<apply_method_modifiers>
195 =item B<apply_override_method_modifiers>
201 All complex software has bugs lurking in it, and this module is no
202 exception. If you find a bug please either email me, or add the bug
207 Stevan Little E<lt>stevan@iinteractive.comE<gt>
209 =head1 COPYRIGHT AND LICENSE
211 Copyright 2006-2008 by Infinity Interactive, Inc.
213 L<http://www.iinteractive.com>
215 This library is free software; you can redistribute it and/or modify
216 it under the same terms as Perl itself.