2 package Class::MOP::Method::Constructor;
8 use Scalar::Util 'blessed', 'weaken', 'looks_like_number';
10 our $VERSION = '0.78';
11 $VERSION = eval $VERSION;
12 our $AUTHORITY = 'cpan:STEVAN';
14 use base 'Class::MOP::Method::Generated';
20 (blessed $options{metaclass} && $options{metaclass}->isa('Class::MOP::Class'))
21 || confess "You must pass a metaclass instance if you want to inline"
22 if $options{is_inline};
24 ($options{package_name} && $options{name})
25 || confess "You must supply the package_name and name parameters $Class::MOP::Method::UPGRADE_ERROR_TEXT";
27 my $self = $class->_new(\%options);
29 # we don't want this creating
30 # a cycle in the code, if not
32 weaken($self->{'associated_metaclass'});
34 $self->initialize_body;
41 my $options = @_ == 1 ? $_[0] : {@_};
46 'package_name' => $options->{package_name},
47 'name' => $options->{name},
48 # specific to this subclass
49 'options' => $options->{options} || {},
50 'associated_metaclass' => $options->{metaclass},
51 'is_inline' => ($options->{is_inline} || 0),
55 sub can_be_inlined { 1 }
59 sub options { (shift)->{'options'} }
60 sub associated_metaclass { (shift)->{'associated_metaclass'} }
66 $self->{'meta_instance'} ||= $self->associated_metaclass->get_meta_instance;
71 $self->{'attributes'} ||= [ $self->associated_metaclass->compute_all_applicable_attributes ]
78 my $method_name = 'generate_constructor_method';
80 $method_name .= '_inline' if $self->is_inline;
82 $self->{'body'} = $self->$method_name;
85 sub generate_constructor_method {
86 return sub { Class::MOP::Class->initialize(shift)->new_object(@_) }
89 sub generate_constructor_method_inline {
95 $source .= "\n" . 'my $class = shift;';
97 $source .= "\n" . 'return Class::MOP::Class->initialize($class)->new_object(@_)';
98 $source .= "\n" . ' if $class ne \'' . $self->associated_metaclass->name . '\';';
100 $source .= "\n" . 'my $params = @_ == 1 ? $_[0] : {@_};';
102 $source .= "\n" . 'my $instance = ' . $self->meta_instance->inline_create_instance('$class');
103 $source .= ";\n" . (join ";\n" => map {
104 $self->_generate_slot_initializer($_, $close_over)
105 } 0 .. (@{$self->attributes} - 1));
106 $source .= ";\n" . 'return $instance';
107 $source .= ";\n" . '}';
108 warn $source if $self->options->{debug};
110 my $code = $self->_eval_closure(
114 confess "Could not eval the constructor :\n\n$source\n\nbecause :\n\n$@" if $@;
119 sub _generate_slot_initializer {
124 my $attr = $self->attributes->[$index];
127 if ($attr->has_default) {
129 # default values can either be CODE refs
130 # in which case we need to call them. Or
131 # they can be scalars (strings/numbers)
132 # in which case we can just deal with them
133 # in the code we eval.
134 if ($attr->is_default_a_coderef) {
135 my $idx = @{$close->{'@defaults'}||=[]};
136 push(@{$close->{'@defaults'}}, $attr->default);
137 $default = '$defaults[' . $idx . ']->($instance)';
140 $default = $attr->default;
141 # make sure to quote strings ...
142 unless (looks_like_number($default)) {
143 $default = "'$default'";
146 } elsif( $attr->has_builder ) {
147 $default = '$instance->'.$attr->builder;
150 if ( defined $attr->init_arg ) {
152 'if(exists $params->{\'' . $attr->init_arg . '\'}){' . "\n" .
153 $self->meta_instance->inline_set_slot_value(
156 '$params->{\'' . $attr->init_arg . '\'}' ) . "\n" .
157 '} ' . (!defined $default ? '' : 'else {' . "\n" .
158 $self->meta_instance->inline_set_slot_value(
164 } elsif ( defined $default ) {
166 $self->meta_instance->inline_set_slot_value(
182 Class::MOP::Method::Constructor - Method Meta Object for constructors
186 use Class::MOP::Method::Constructor;
188 my $constructor = Class::MOP::Method::Constructor->new(
189 metaclass => $metaclass,
191 debug => 1, # this is all for now
195 # calling the constructor ...
196 $constructor->body->execute($metaclass->name, %params);
200 This is a subclass of C<Class::MOP::Method> which generates
207 =item B<< Class::MOP::Method::Constructor->new(%options) >>
209 This creates a new constructor object. It accepts a hash reference of
216 This should be a L<Class::MOP::Class> object. It is required.
220 The method name (without a package name). This is required.
224 The package name for the method. This is required.
228 This indicates whether or not the constructor should be inlined. This
233 =item B<< $metamethod->is_inline >>
235 Returns a boolean indicating whether or not the constructor is
238 =item B<< $metamethod->associated_metaclass >>
240 This returns the L<Class::MOP::Class> object for the method.
242 =item B<< $metamethod->is_inline >>
244 Returns a boolean indicating whether or not the constructor is
247 =item B<< $metamethod->can_be_inlined >>
249 This method always returns true in this class. It exists so that
250 subclasses (as in Moose) can do some sort of checking to determine
251 whether or not inlining the constructor is safe.
257 Stevan Little E<lt>stevan@iinteractive.comE<gt>
259 =head1 COPYRIGHT AND LICENSE
261 Copyright 2006-2009 by Infinity Interactive, Inc.
263 L<http://www.iinteractive.com>
265 This library is free software; you can redistribute it and/or modify
266 it under the same terms as Perl itself.