2 package Moose::Meta::Method::Constructor;
8 use Scalar::Util 'blessed', 'weaken', 'looks_like_number';
10 our $VERSION = '0.01';
11 our $AUTHORITY = 'cpan:STEVAN';
13 use base 'Moose::Meta::Method';
19 (exists $options{options} && ref $options{options} eq 'HASH')
20 || confess "You must pass a hash of options";
25 # specific to this subclass
26 '%!options' => $options{options},
27 '$!meta_instance' => $options{metaclass}->get_meta_instance,
28 '@!attributes' => [ $options{metaclass}->compute_all_applicable_attributes ],
30 '$!associated_metaclass' => $options{metaclass},
33 # we don't want this creating
34 # a cycle in the code, if not
36 # weaken($self->{'$!meta_instance'});
37 weaken($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 = $self->attributes;
91 confess "Could not eval the constructor :\n\n$source\n\nbecause :\n\n$@" if $@;
93 $self->{'&!body'} = $code;
96 sub _generate_BUILDALL {
99 foreach my $method (reverse $self->associated_metaclass->find_all_methods_by_name('BUILD')) {
100 push @BUILD_calls => '$instance->' . $method->{class} . '::BUILD(\%params)';
102 return join "\n" => @BUILD_calls;
105 sub _generate_slot_initializer {
109 my $attr = $self->attributes->[$index];
111 my @source = ('## ' . $attr->name);
113 if ($attr->is_required && !$attr->has_default) {
114 push @source => ('(exists $params{\'' . $attr->init_arg . '\'}) ' .
115 '|| confess "Attribute (' . $attr->name . ') is required";');
118 if ($attr->has_default && !$attr->is_lazy) {
120 push @source => 'if (exists $params{\'' . $attr->init_arg . '\'}) {';
122 push @source => ('my $val = $params{\'' . $attr->init_arg . '\'};');
123 if ($attr->has_type_constraint) {
124 push @source => ('my $type_constraint = $attrs->[' . $index . ']->type_constraint;');
126 if ($attr->should_coerce && $attr->type_constraint->has_coercion) {
127 push @source => $self->_generate_type_coercion($attr, '$type_constraint', '$val', '$val');
129 push @source => $self->_generate_type_constraint_check($attr, '$type_constraint', '$val');
131 push @source => $self->_generate_slot_assignment($attr, '$val');
134 push @source => "} else {";
136 my $default = $self->_generate_default_value($attr, $index);
138 push @source => ('my $val = ' . $default . ';');
139 push @source => $self->_generate_type_constraint_check(
141 ('$attrs->[' . $index . ']->type_constraint'),
143 ) if $attr->has_type_constraint;
144 push @source => $self->_generate_slot_assignment($attr, $default);
149 push @source => '(exists $params{\'' . $attr->init_arg . '\'}) && do {';
151 push @source => ('my $val = $params{\'' . $attr->init_arg . '\'};');
152 if ($attr->has_type_constraint) {
153 push @source => ('my $type_constraint = $attrs->[' . $index . ']->type_constraint;');
155 if ($attr->should_coerce && $attr->type_constraint->has_coercion) {
156 push @source => $self->_generate_type_coercion($attr, '$type_constraint', '$val', '$val');
158 push @source => $self->_generate_type_constraint_check($attr, '$type_constraint', '$val');
160 push @source => $self->_generate_slot_assignment($attr, '$val');
165 return join "\n" => @source;
168 sub _generate_slot_assignment {
169 my ($self, $attr, $value) = @_;
171 $self->meta_instance->inline_set_slot_value(
173 ("'" . $attr->name . "'"),
178 if ($attr->is_weak_ref) {
181 $self->meta_instance->inline_weaken_slot_value(
183 ("'" . $attr->name . "'")
185 ' if ref ' . $value . ';'
192 sub _generate_type_coercion {
193 my ($self, $attr, $type_constraint_name, $value_name, $return_value_name) = @_;
194 return ($return_value_name . ' = ' . $type_constraint_name . '->coerce(' . $value_name . ');');
197 sub _generate_type_constraint_check {
198 my ($self, $attr, $type_constraint_name, $value_name) = @_;
200 'defined(' . $type_constraint_name . '->_compiled_type_constraint->(' . $value_name . '))'
201 . "\n\t" . '|| confess "Attribute (' . $attr->name . ') does not pass the type constraint ('
202 . $attr->type_constraint->name . ') with " . (defined() ? "' . $value_name . '" : "undef");'
206 sub _generate_default_value {
207 my ($self, $attr, $index) = @_;
209 # default values can either be CODE refs
210 # in which case we need to call them. Or
211 # they can be scalars (strings/numbers)
212 # in which case we can just deal with them
213 # in the code we eval.
214 if ($attr->is_default_a_coderef) {
215 return '$attrs->[' . $index . ']->default($instance)';
218 my $default = $attr->default;
219 # make sure to quote strings ...
220 unless (looks_like_number($default)) {
221 $default = "'$default'";
238 Moose::Meta::Method::Constructor - Method Meta Object for constructors
252 =item B<meta_instance>
256 =item B<intialize_body>
258 =item B<associated_metaclass>
264 Stevan Little E<lt>stevan@iinteractive.comE<gt>
266 =head1 COPYRIGHT AND LICENSE
268 Copyright 2006 by Infinity Interactive, Inc.
270 L<http://www.iinteractive.com>
272 This library is free software; you can redistribute it and/or modify
273 it under the same terms as Perl itself.