2 package Class::MOP::Method::Accessor;
8 use Scalar::Util 'blessed', 'weaken';
11 our $VERSION = '1.11';
12 $VERSION = eval $VERSION;
13 our $AUTHORITY = 'cpan:STEVAN';
15 use base 'Class::MOP::Method::Generated';
21 (exists $options{attribute})
22 || confess "You must supply an attribute to construct with";
24 (exists $options{accessor_type})
25 || confess "You must supply an accessor_type to construct with";
27 (blessed($options{attribute}) && $options{attribute}->isa('Class::MOP::Attribute'))
28 || confess "You must supply an attribute which is a 'Class::MOP::Attribute' instance";
30 ($options{package_name} && $options{name})
31 || confess "You must supply the package_name and name parameters $Class::MOP::Method::UPGRADE_ERROR_TEXT";
33 my $self = $class->_new(\%options);
35 # we don't want this creating
36 # a cycle in the code, if not
38 weaken($self->{'attribute'});
40 $self->_initialize_body;
48 return Class::MOP::Class->initialize($class)->new_object(@_)
49 if $class ne __PACKAGE__;
51 my $params = @_ == 1 ? $_[0] : {@_};
54 # inherited from Class::MOP::Method
55 body => $params->{body},
56 associated_metaclass => $params->{associated_metaclass},
57 package_name => $params->{package_name},
58 name => $params->{name},
59 original_method => $params->{original_method},
61 # inherit from Class::MOP::Generated
62 is_inline => $params->{is_inline} || 0,
63 definition_context => $params->{definition_context},
65 # defined in this class
66 attribute => $params->{attribute},
67 accessor_type => $params->{accessor_type},
73 sub associated_attribute { (shift)->{'attribute'} }
74 sub accessor_type { (shift)->{'accessor_type'} }
78 sub _initialize_body {
81 my $method_name = join "_" => (
85 ($self->is_inline ? 'inline' : ())
88 $self->{'body'} = $self->$method_name();
93 sub _generate_accessor_method {
94 my $attr = (shift)->associated_attribute;
96 $attr->set_value($_[0], $_[1]) if scalar(@_) == 2;
97 $attr->get_value($_[0]);
101 sub _generate_reader_method {
102 my $attr = (shift)->associated_attribute;
104 confess "Cannot assign a value to a read-only accessor" if @_ > 1;
105 $attr->get_value($_[0]);
110 sub _generate_writer_method {
111 my $attr = (shift)->associated_attribute;
113 $attr->set_value($_[0], $_[1]);
117 sub _generate_predicate_method {
118 my $attr = (shift)->associated_attribute;
120 $attr->has_value($_[0])
124 sub _generate_clearer_method {
125 my $attr = (shift)->associated_attribute;
127 $attr->clear_value($_[0])
133 sub _generate_accessor_method_inline {
135 my $attr = $self->associated_attribute;
138 $self->_compile_code(
141 $attr->inline_set( '$_[0]', '$_[1]' )
142 . ' if scalar(@_) == 2;',
143 $attr->inline_get('$_[0]') . ';',
149 confess "Could not generate inline accessor because : $_";
155 sub _generate_reader_method_inline {
157 my $attr = $self->associated_attribute;
160 $self->_compile_code(
163 'confess "Cannot assign a value to a read-only accessor" '
165 $attr->inline_get('$_[0]') . ';',
171 confess "Could not generate inline reader because : $_";
177 sub _generate_writer_method_inline {
179 my $attr = $self->associated_attribute;
182 $self->_compile_code(
185 $attr->inline_set( '$_[0]', '$_[1]' ) . ';',
191 confess "Could not generate inline writer because : $_";
197 sub _generate_predicate_method_inline {
199 my $attr = $self->associated_attribute;
202 $self->_compile_code(
205 $attr->inline_has('$_[0]') . ';',
211 confess "Could not generate inline predicate because : $_";
217 sub _generate_clearer_method_inline {
219 my $attr = $self->associated_attribute;
222 $self->_compile_code(
225 $attr->inline_clear('$_[0]') . ';',
231 confess "Could not generate inline clearer because : $_";
245 Class::MOP::Method::Accessor - Method Meta Object for accessors
249 use Class::MOP::Method::Accessor;
251 my $reader = Class::MOP::Method::Accessor->new(
252 attribute => $attribute,
254 accessor_type => 'reader',
257 $reader->body->execute($instance); # call the reader method
261 This is a subclass of C<Class::MOP::Method> which is used by
262 C<Class::MOP::Attribute> to generate accessor code. It handles
263 generation of readers, writers, predicates and clearers. For each type
264 of method, it can either create a subroutine reference, or actually
265 inline code by generating a string and C<eval>'ing it.
271 =item B<< Class::MOP::Method::Accessor->new(%options) >>
273 This returns a new C<Class::MOP::Method::Accessor> based on the
274 C<%options> provided.
280 This is the C<Class::MOP::Attribute> for which accessors are being
281 generated. This option is required.
283 =item * accessor_type
285 This is a string which should be one of "reader", "writer",
286 "accessor", "predicate", or "clearer". This is the type of method
287 being generated. This option is required.
291 This indicates whether or not the accessor should be inlined. This
296 The method name (without a package name). This is required.
300 The package name for the method. This is required.
304 =item B<< $metamethod->accessor_type >>
306 Returns the accessor type which was passed to C<new>.
308 =item B<< $metamethod->is_inline >>
310 Returns a boolean indicating whether or not the accessor is inlined.
312 =item B<< $metamethod->associated_attribute >>
314 This returns the L<Class::MOP::Attribute> object which was passed to
317 =item B<< $metamethod->body >>
319 The method itself is I<generated> when the accessor object is
326 Stevan Little E<lt>stevan@iinteractive.comE<gt>
328 =head1 COPYRIGHT AND LICENSE
330 Copyright 2006-2010 by Infinity Interactive, Inc.
332 L<http://www.iinteractive.com>
334 This library is free software; you can redistribute it and/or modify
335 it under the same terms as Perl itself.