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 $required_method_name ($role1->get_required_method_list) {
40 next if $self->is_aliased_method($required_method_name);
42 $role2->add_required_methods($required_method_name)
43 unless $role2->find_method_by_name($required_method_name);
47 sub check_required_attributes {
51 sub apply_attributes {
52 my ($self, $role1, $role2) = @_;
53 foreach my $attribute_name ($role1->get_attribute_list) {
54 # it if it has one already
55 if ($role2->has_attribute($attribute_name) &&
56 # make sure we haven't seen this one already too
57 $role2->get_attribute($attribute_name) != $role1->get_attribute($attribute_name)) {
60 Moose->throw_error("Role '" . $role1->name . "' has encountered an attribute conflict " .
61 "during composition. This is fatal error and cannot be disambiguated.");
64 $role2->add_attribute(
66 $role1->get_attribute($attribute_name)
73 my ($self, $role1, $role2) = @_;
74 foreach my $method_name ($role1->get_method_list) {
76 if ($self->is_method_aliased($method_name)) {
77 my $aliased_method_name = $self->get_method_aliases->{$method_name};
78 # it if it has one already
79 if ($role2->has_method($aliased_method_name) &&
80 # and if they are not the same thing ...
81 $role2->get_method($aliased_method_name)->body != $role1->get_method($method_name)->body) {
84 Moose->throw_error("Cannot create a method alias if a local method of the same name exists");
89 $role1->get_method($method_name)
92 if (!$role2->has_method($method_name)) {
93 $role2->add_required_methods($method_name)
94 unless $self->is_method_excluded($method_name);
100 next if $self->is_method_excluded($method_name);
102 # it if it has one already
103 if ($role2->has_method($method_name) &&
104 # and if they are not the same thing ...
105 $role2->get_method($method_name)->body != $role1->get_method($method_name)->body) {
106 # method conflicts between roles result
107 # in the method becoming a requirement
108 $role2->add_required_methods($method_name);
111 # add it, although it could be overridden
114 $role1->get_method($method_name)
122 sub apply_override_method_modifiers {
123 my ($self, $role1, $role2) = @_;
124 foreach my $method_name ($role1->get_method_modifier_list('override')) {
125 # it if it has one already then ...
126 if ($role2->has_method($method_name)) {
127 # if it is being composed into another role
128 # we have a conflict here, because you cannot
129 # combine an overridden method with a locally
132 Moose->throw_error("Role '" . $role1->name . "' has encountered an 'override' method conflict " .
133 "during composition (A local method of the same name as been found). This " .
137 # if we are a role, we need to make sure
138 # we dont have a conflict with the role
139 # we are composing into
140 if ($role2->has_override_method_modifier($method_name) &&
141 $role2->get_override_method_modifier($method_name) != $role2->get_override_method_modifier($method_name)) {
144 Moose->throw_error("Role '" . $role1->name . "' has encountered an 'override' method conflict " .
145 "during composition (Two 'override' methods of the same name encountered). " .
146 "This is fatal error.");
149 # if there is no conflict,
150 # just add it to the role
151 $role2->add_override_method_modifier(
153 $role1->get_override_method_modifier($method_name)
160 sub apply_method_modifiers {
161 my ($self, $modifier_type, $role1, $role2) = @_;
162 my $add = "add_${modifier_type}_method_modifier";
163 my $get = "get_${modifier_type}_method_modifiers";
164 foreach my $method_name ($role1->get_method_modifier_list($modifier_type)) {
168 ) foreach $role1->$get($method_name);
181 Moose::Meta::Role::Application::ToRole - Compose a role into another role
195 =item B<check_role_exclusions>
197 =item B<check_required_methods>
199 =item B<check_required_attributes>
201 =item B<apply_attributes>
203 =item B<apply_methods>
205 =item B<apply_method_modifiers>
207 =item B<apply_override_method_modifiers>
213 All complex software has bugs lurking in it, and this module is no
214 exception. If you find a bug please either email me, or add the bug
219 Stevan Little E<lt>stevan@iinteractive.comE<gt>
221 =head1 COPYRIGHT AND LICENSE
223 Copyright 2006-2009 by Infinity Interactive, Inc.
225 L<http://www.iinteractive.com>
227 This library is free software; you can redistribute it and/or modify
228 it under the same terms as Perl itself.