[gitmo/Class-MOP.git] / lib / Class / MOP / Method / Meta.pm


package Class::MOP::Method::Meta;

use strict;
use warnings;

use Carp         'confess';
use Scalar::Util 'blessed';

our $VERSION   = '1.08';
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';

use constant DEBUG_NO_META => $ENV{DEBUG_NO_META};

use base 'Class::MOP::Method';

sub _generate_meta_method {
    my $method_self = shift;
    my $metaclass   = shift;
    sub {
        # this will be compiled out if the env var wasn't set
        if (DEBUG_NO_META) {
            my ($self) = @_;
            # it's okay if we installed a meta method in a subclass of a class
            # with a legitimate meta method (we'll still die if we install a
            # meta method in a subclass of a class we installed a meta method
            # in, since this function is itself defined in Class::MOP)
            #if (my $meta = try { $self->SUPER::meta }) {
                #return $meta if $meta->isa('Class::MOP::Class');
            #}
            # it's okay if the test itself calls ->meta, we only care about if
            # the mop internals call ->meta
            confess "'meta' method called by MOP internals"
                if caller =~ /^(?:Class::MOP|metaclass)(?:::|$)/;
        }
        # we must re-initialize so that it
        # works as expected in subclasses,
        # since metaclass instances are
        # singletons, this is not really a
        # big deal anyway.
        $metaclass->initialize(blessed($_[0]) || $_[0])
    };
}

sub wrap {
    my ($class, @args) = @_;

    unshift @args, 'body' if @args % 2 == 1;
    my %params = @args;
    confess "Overriding the body of meta methods is not allowed"
        if $params{body};

    my $metaclass_class = $params{associated_metaclass}->meta;
    $params{body} = $class->_generate_meta_method($metaclass_class);
    return $class->SUPER::wrap(%params);
}

1;

__END__

=pod

=head1 NAME

Class::MOP::Method::Meta - Method Meta Object for C<meta> methods

=head1 DESCRIPTION

This is a L<Class::MOP::Method> subclass which represents C<meta>
methods installed into classes by Class::MOP.

=head1 METHODS

=over 4

=item B<< Class::MOP::Method::Wrapped->wrap($metamethod, %options) >>

This is the constructor. It accepts a L<Class::MOP::Method> object and
a hash of options. The options accepted are identical to the ones
accepted by L<Class::MOP::Method>, except that C<body> cannot be passed
(it will be generated automatically).

=back

=head1 AUTHORS

Jesse Luehrs E<lt>doy at tozt dot netE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright 2006-2010 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
Commit	Line	Data
59b51046	1
	2	package Class::MOP::Method::Meta;
	3
	4	use strict;
	5	use warnings;
	6
	7	use Carp 'confess';
	8	use Scalar::Util 'blessed';
	9
	10	our $VERSION = '1.08';
	11	$VERSION = eval $VERSION;
	12	our $AUTHORITY = 'cpan:STEVAN';
	13
	14	use constant DEBUG_NO_META => $ENV{DEBUG_NO_META};
	15
	16	use base 'Class::MOP::Method';
	17
	18	sub _generate_meta_method {
	19	my $method_self = shift;
	20	my $metaclass = shift;
	21	sub {
	22	# this will be compiled out if the env var wasn't set
	23	if (DEBUG_NO_META) {
	24	my ($self) = @_;
	25	# it's okay if we installed a meta method in a subclass of a class
	26	# with a legitimate meta method (we'll still die if we install a
	27	# meta method in a subclass of a class we installed a meta method
	28	# in, since this function is itself defined in Class::MOP)
	29	#if (my $meta = try { $self->SUPER::meta }) {
	30	#return $meta if $meta->isa('Class::MOP::Class');
	31	#}
	32	# it's okay if the test itself calls ->meta, we only care about if
	33	# the mop internals call ->meta
	34	confess "'meta' method called by MOP internals"
	35	if caller =~ /^(?:Class::MOP\|metaclass)(?:::\|$)/;
	36	}
	37	# we must re-initialize so that it
	38	# works as expected in subclasses,
	39	# since metaclass instances are
	40	# singletons, this is not really a
	41	# big deal anyway.
	42	$metaclass->initialize(blessed($_[0]) \|\| $_[0])
	43	};
	44	}
	45
	46	sub wrap {
	47	my ($class, @args) = @_;
	48
	49	unshift @args, 'body' if @args % 2 == 1;
	50	my %params = @args;
	51	confess "Overriding the body of meta methods is not allowed"
	52	if $params{body};
	53
	54	my $metaclass_class = $params{associated_metaclass}->meta;
	55	$params{body} = $class->_generate_meta_method($metaclass_class);
	56	return $class->SUPER::wrap(%params);
	57	}
	58
	59	1;
	60
	61	__END__
	62
	63	=pod
	64
65	=head1 NAME
66
67	Class::MOP::Method::Meta - Method Meta Object for C<meta> methods
68
69	=head1 DESCRIPTION
70
71	This is a L<Class::MOP::Method> subclass which represents C<meta>
72	methods installed into classes by Class::MOP.
73
74	=head1 METHODS
75
76	=over 4
77
78	=item B<< Class::MOP::Method::Wrapped->wrap($metamethod, %options) >>
79
80	This is the constructor. It accepts a L<Class::MOP::Method> object and
81	a hash of options. The options accepted are identical to the ones
82	accepted by L<Class::MOP::Method>, except that C<body> cannot be passed
83	(it will be generated automatically).
84
85	=back
86
87	=head1 AUTHORS
88
89	Jesse Luehrs E<lt>doy at tozt dot netE<gt>
90
91	=head1 COPYRIGHT AND LICENSE
92
93	Copyright 2006-2010 by Infinity Interactive, Inc.
94
95	L<http://www.iinteractive.com>
96
97	This library is free software; you can redistribute it and/or modify
98	it under the same terms as Perl itself.
99
100	=cut
101