2 package Moose::Meta::Method::Constructor;
8 use Scalar::Util 'blessed', 'weaken', 'looks_like_number';
10 our $VERSION = '0.05';
11 our $AUTHORITY = 'cpan:STEVAN';
13 use base 'Moose::Meta::Method',
14 'Class::MOP::Method::Generated';
20 (exists $options{options} && ref $options{options} eq 'HASH')
21 || confess "You must pass a hash of options";
26 # specific to this subclass
27 '%!options' => $options{options},
28 '$!meta_instance' => $options{metaclass}->get_meta_instance,
29 '@!attributes' => [ $options{metaclass}->compute_all_applicable_attributes ],
31 '$!associated_metaclass' => $options{metaclass},
34 # we don't want this creating
35 # a cycle in the code, if not
37 weaken($self->{'$!associated_metaclass'});
39 $self->intialize_body;
46 sub options { (shift)->{'%!options'} }
47 sub meta_instance { (shift)->{'$!meta_instance'} }
48 sub attributes { (shift)->{'@!attributes'} }
50 sub associated_metaclass { (shift)->{'$!associated_metaclass'} }
57 # the %options should also include a both
58 # a call 'initializer' and call 'SUPER::'
59 # options, which should cover approx 90%
60 # of the possible use cases (even if it
61 # requires some adaption on the part of
62 # the author, after all, nothing is free)
64 $source .= "\n" . 'my $class = shift;';
66 $source .= "\n" . 'return $class->Moose::Object::new(@_)';
67 $source .= "\n" . ' if $class ne \'' . $self->associated_metaclass->name . '\';';
69 $source .= "\n" . 'my %params = (scalar @_ == 1) ? %{$_[0]} : @_;';
71 $source .= "\n" . 'my $instance = ' . $self->meta_instance->inline_create_instance('$class');
73 $source .= ";\n" . (join ";\n" => map {
74 $self->_generate_slot_initializer($_)
75 } 0 .. (@{$self->attributes} - 1));
77 $source .= ";\n" . $self->_generate_BUILDALL();
79 $source .= ";\n" . 'return $instance';
80 $source .= ";\n" . '}';
81 warn $source if $self->options->{debug};
86 # create the nessecary lexicals
87 # to be picked up in the eval
88 my $attrs = $self->attributes;
90 # We need to check if the attribute ->can('type_constraint')
91 # since we may be trying to immutabilize a Moose meta class,
92 # which in turn has attributes which are Class::MOP::Attribute
93 # objects, rather than Moose::Meta::Attribute. And
94 # Class::MOP::Attribute attributes have no type constraints.
95 # However we need to make sure we leave an undef value there
96 # because the inlined code is using the index of the attributes
97 # to determine where to find the type constraint
99 my @type_constraints = map {
100 $_->can('type_constraint') ? $_->type_constraint : undef
103 my @type_constraint_bodies = map {
104 defined $_ ? $_->_compiled_type_constraint : undef;
107 $code = eval $source;
108 confess "Could not eval the constructor :\n\n$source\n\nbecause :\n\n$@" if $@;
110 $self->{'&!body'} = $code;
113 sub _generate_BUILDALL {
116 foreach my $method (reverse $self->associated_metaclass->find_all_methods_by_name('BUILD')) {
117 push @BUILD_calls => '$instance->' . $method->{class} . '::BUILD(\%params)';
119 return join ";\n" => @BUILD_calls;
122 sub _generate_slot_initializer {
126 my $attr = $self->attributes->[$index];
128 my @source = ('## ' . $attr->name);
130 my $is_moose = $attr->isa('Moose::Meta::Attribute'); # XXX FIXME
132 if ($is_moose && defined($attr->init_arg) && $attr->is_required && !$attr->has_default && !$attr->has_builder) {
133 push @source => ('(exists $params{\'' . $attr->init_arg . '\'}) ' .
134 '|| confess "Attribute (' . $attr->name . ') is required";');
137 if (($attr->has_default || $attr->has_builder) && !($is_moose && $attr->is_lazy)) {
139 if ( defined( my $init_arg = $attr->init_arg ) ) {
140 push @source => 'if (exists $params{\'' . $init_arg . '\'}) {';
142 push @source => ('my $val = $params{\'' . $init_arg . '\'};');
144 if ($is_moose && $attr->has_type_constraint) {
145 if ($attr->should_coerce && $attr->type_constraint->has_coercion) {
146 push @source => $self->_generate_type_coercion(
148 '$type_constraints[' . $index . ']',
153 push @source => $self->_generate_type_constraint_check(
155 '$type_constraint_bodies[' . $index . ']',
156 '$type_constraints[' . $index . ']',
160 push @source => $self->_generate_slot_assignment($attr, '$val', $index);
162 push @source => "} else {";
165 if ( $attr->has_default ) {
166 $default = $self->_generate_default_value($attr, $index);
169 my $builder = $attr->builder;
170 $default = '$instance->' . $builder;
173 push @source => '{'; # wrap this to avoid my $val overrite warnings
174 push @source => ('my $val = ' . $default . ';');
175 push @source => $self->_generate_type_constraint_check(
177 ('$type_constraint_bodies[' . $index . ']'),
178 ('$type_constraints[' . $index . ']'),
180 ) if ($is_moose && $attr->has_type_constraint);
181 push @source => $self->_generate_slot_assignment($attr, $default, $index);
182 push @source => '}'; # close - wrap this to avoid my $val overrite warnings
184 push @source => "}" if defined $attr->init_arg;
186 elsif ( defined( my $init_arg = $attr->init_arg ) ) {
187 push @source => '(exists $params{\'' . $init_arg . '\'}) && do {';
189 push @source => ('my $val = $params{\'' . $init_arg . '\'};');
190 if ($is_moose && $attr->has_type_constraint) {
191 if ($attr->should_coerce && $attr->type_constraint->has_coercion) {
192 push @source => $self->_generate_type_coercion(
194 '$type_constraints[' . $index . ']',
199 push @source => $self->_generate_type_constraint_check(
201 '$type_constraint_bodies[' . $index . ']',
202 '$type_constraints[' . $index . ']',
206 push @source => $self->_generate_slot_assignment($attr, '$val', $index);
211 return join "\n" => @source;
214 sub _generate_slot_assignment {
215 my ($self, $attr, $value, $index) = @_;
219 if ($attr->has_initializer) {
221 '$attrs->[' . $index . ']->set_initial_value($instance, ' . $value . ');'
226 $self->meta_instance->inline_set_slot_value(
228 ("'" . $attr->name . "'"),
234 my $is_moose = $attr->isa('Moose::Meta::Attribute'); # XXX FIXME
236 if ($is_moose && $attr->is_weak_ref) {
239 $self->meta_instance->inline_weaken_slot_value(
241 ("'" . $attr->name . "'")
243 ' if ref ' . $value . ';'
250 sub _generate_type_coercion {
251 my ($self, $attr, $type_constraint_name, $value_name, $return_value_name) = @_;
252 return ($return_value_name . ' = ' . $type_constraint_name . '->coerce(' . $value_name . ');');
255 sub _generate_type_constraint_check {
256 my ($self, $attr, $type_constraint_cv, $type_constraint_obj, $value_name) = @_;
258 $type_constraint_cv . '->(' . $value_name . ')'
259 . "\n\t" . '|| confess "Attribute ('
261 . ') does not pass the type constraint because: " . '
262 . $type_constraint_obj . '->get_message(' . $value_name . ');'
266 sub _generate_default_value {
267 my ($self, $attr, $index) = @_;
269 # default values can either be CODE refs
270 # in which case we need to call them. Or
271 # they can be scalars (strings/numbers)
272 # in which case we can just deal with them
273 # in the code we eval.
274 if ($attr->is_default_a_coderef) {
275 return '$attrs->[' . $index . ']->default($instance)';
278 my $default = $attr->default;
279 # make sure to quote strings ...
280 unless (looks_like_number($default)) {
281 $default = "'$default'";
296 Moose::Meta::Method::Constructor - Method Meta Object for constructors
300 This is a subclass of L<Class::MOP::Method> which handles
301 constructing an approprate Constructor methods. This is primarily
302 used in the making of immutable metaclasses, otherwise it is
303 not particularly useful.
313 =item B<meta_instance>
317 =item B<intialize_body>
319 =item B<associated_metaclass>
325 Stevan Little E<lt>stevan@iinteractive.comE<gt>
327 =head1 COPYRIGHT AND LICENSE
329 Copyright 2006-2008 by Infinity Interactive, Inc.
331 L<http://www.iinteractive.com>
333 This library is free software; you can redistribute it and/or modify
334 it under the same terms as Perl itself.