package MooseX::AttributeHelpers::Base;
use Moose;
use Moose::Util::TypeConstraints;
our $VERSION = '0.04';
our $AUTHORITY = 'cpan:STEVAN';
extends 'Moose::Meta::Attribute';
# this is the method map you define ...
has 'provides' => (
is => 'ro',
isa => 'HashRef',
default => sub {{}}
);
# these next two are the possible methods
# you can use in the 'provides' map.
# provide a Class or Role which we can
# collect the method providers from
has 'method_provider' => (
is => 'ro',
isa => 'ClassName',
predicate => 'has_method_provider',
);
# or you can provide a HASH ref of anon subs
# yourself. This will also collect and store
# the methods from a method_provider as well
has 'method_constructors' => (
is => 'ro',
isa => 'HashRef',
lazy => 1,
default => sub {
my $self = shift;
return +{} unless $self->has_method_provider;
# or grab them from the role/class
my $method_provider = $self->method_provider->meta;
return +{
map {
$_ => $method_provider->get_method($_)
} $method_provider->get_method_list
};
},
);
# extend the parents stuff to make sure
# certain bits are now required ...
has '+$!default' => (required => 1);
has '+type_constraint' => (required => 1);
## Methods called prior to instantiation
sub helper_type { () }
sub process_options_for_provides {
my ($self, $options) = @_;
if (my $type = $self->helper_type) {
(exists $options->{isa})
|| confess "You must define a type with the $type metaclass";
my $isa = $options->{isa};
unless (blessed($isa) && $isa->isa('Moose::Meta::TypeConstraint')) {
$isa = Moose::Util::TypeConstraints::find_or_create_type_constraint($isa);
}
($isa->is_a_type_of($type))
|| confess "The type constraint for a $type ($options->{isa}) must be a subtype of $type";
}
}
before '_process_options' => sub {
my ($self, $name, $options) = @_;
$self->process_options_for_provides($options, $name);
};
## methods called after instantiation
# this confirms that provides has
# all valid possibilities in it
sub check_provides_values {
my $self = shift;
my $method_constructors = $self->method_constructors;
foreach my $key (keys %{$self->provides}) {
(exists $method_constructors->{$key})
|| confess "$key is an unsupported method type";
}
}
after 'install_accessors' => sub {
my $attr = shift;
my $class = $attr->associated_class;
# grab the reader and writer methods
# as well, this will be useful for
# our method provider constructors
my $attr_reader = $attr->get_read_method_ref;
my $attr_writer = $attr->get_write_method_ref;
# before we install them, lets
# make sure they are valid
$attr->check_provides_values;
my $method_constructors = $attr->method_constructors;
foreach my $key (keys %{$attr->provides}) {
my $method_name = $attr->provides->{$key};
if ($class->has_method($method_name)) {
confess "The method ($method_name) already exists in class (" . $class->name . ")";
}
my $method = MooseX::AttributeHelpers::Meta::Method::Provided->wrap(
$method_constructors->{$key}->(
$attr,
$attr_reader,
$attr_writer,
)
);
$attr->associate_method($method);
$class->add_method($method_name => $method);
}
};
after 'remove_accessors' => sub {
my $attr = shift;
my $class = $attr->associated_class;
foreach my $key (keys %{$attr->provides}) {
my $method_name = $attr->provides->{$key};
my $method = $class->get_method($method_name);
$class->remove_method($method_name)
if blessed($method) &&
$method->isa('MooseX::AttributeHelpers::Meta::Method::Provided');
}
};
no Moose;
no Moose::Util::TypeConstraints;
1;
__END__
=pod
=head1 NAME
MooseX::AttributeHelpers::Base - Base class for attribute helpers
=head1 DESCRIPTION
Documentation to come.
=head1 ATTRIBUTES
=over 4
=item B<provides>
=item B<method_provider>
=item B<method_constructors>
=back
=head1 EXTENDED ATTRIBUTES
=over 4
=item B<$!default>
C<$!default> is now required.
=item B<type_constraint>
C<type_constraint> is now required.
=back
=head1 METHODS
=over 4
=item B<meta>
=item B<helper_type>
=item B<check_provides_values>
=item B<has_default>
=item B<has_method_provider>
=item B<has_type_constraint>
=item B<install_accessors>
=item B<remove_accessors>
=item B<process_options_for_provides>
=back
=head1 BUGS
All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
=head1 AUTHOR
Stevan Little E<lt>stevan@iinteractive.comE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright 2007 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut