2 package MooseX::AttributeHelpers::Trait::Base;
4 use Moose::Util::TypeConstraints;
7 our $AUTHORITY = 'cpan:STEVAN';
9 requires 'helper_type';
11 # this is the method map you define ...
19 # these next two are the possible methods
20 # you can use in the 'provides' map.
22 # provide a Class or Role which we can
23 # collect the method providers from
24 has 'method_provider' => (
27 predicate => 'has_method_provider',
30 # or you can provide a HASH ref of anon subs
31 # yourself. This will also collect and store
32 # the methods from a method_provider as well
33 has 'method_constructors' => (
39 return +{} unless $self->has_method_provider;
40 # or grab them from the role/class
41 my $method_provider = $self->method_provider->meta;
44 $_ => $method_provider->get_method($_)
45 } $method_provider->get_method_list
50 # extend the parents stuff to make sure
51 # certain bits are now required ...
52 has '+$!default' => (required => 1);
53 has '+type_constraint' => (required => 1);
55 ## Methods called prior to instantiation
57 sub process_options_for_provides {
58 my ($self, $options) = @_;
60 if (my $type = $self->helper_type) {
61 (exists $options->{isa})
62 || confess "You must define a type with the $type metaclass";
64 my $isa = $options->{isa};
66 unless (blessed($isa) && $isa->isa('Moose::Meta::TypeConstraint')) {
67 $isa = Moose::Util::TypeConstraints::find_or_create_type_constraint($isa);
70 ($isa->is_a_type_of($type))
71 || confess "The type constraint for a $type ($options->{isa}) must be a subtype of $type";
75 before '_process_options' => sub {
76 my ($self, $name, $options) = @_;
77 $self->process_options_for_provides($options, $name);
80 ## methods called after instantiation
82 # this confirms that provides has
83 # all valid possibilities in it
84 sub check_provides_values {
87 my $method_constructors = $self->method_constructors;
89 foreach my $key (keys %{$self->provides}) {
90 (exists $method_constructors->{$key})
91 || confess "$key is an unsupported method type";
95 after 'install_accessors' => sub {
97 my $class = $attr->associated_class;
99 # grab the reader and writer methods
100 # as well, this will be useful for
101 # our method provider constructors
102 my $attr_reader = $attr->get_read_method_ref;
103 my $attr_writer = $attr->get_write_method_ref;
106 # before we install them, lets
107 # make sure they are valid
108 $attr->check_provides_values;
110 my $method_constructors = $attr->method_constructors;
112 my $class_name = $class->name;
114 foreach my $key (keys %{$attr->provides}) {
116 my $method_name = $attr->provides->{$key};
118 if ($class->has_method($method_name)) {
119 confess "The method ($method_name) already exists in class (" . $class->name . ")";
122 my $method = MooseX::AttributeHelpers::Meta::Method::Provided->wrap(
123 $method_constructors->{$key}->(
128 package_name => $class_name,
129 name => $method_name,
132 $attr->associate_method($method);
133 $class->add_method($method_name => $method);
137 after 'remove_accessors' => sub {
139 my $class = $attr->associated_class;
140 foreach my $key (keys %{$attr->provides}) {
141 my $method_name = $attr->provides->{$key};
142 my $method = $class->get_method($method_name);
143 $class->remove_method($method_name)
144 if blessed($method) &&
145 $method->isa('MooseX::AttributeHelpers::Meta::Method::Provided');
150 no Moose::Util::TypeConstraints;