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use strict;
package Class::Accessor::Lvalue;
use base qw( Class::Accessor );
use Scalar::Util qw(weaken);
use Want qw( want );
our $VERSION = '0.11';
sub make_accessor {
my ($class, $field) = @_;
return sub :lvalue {
tie my $tie, "Class::Accessor::Lvalue::Tied" => $field, @_;
$tie;
};
}
sub make_ro_accessor {
my ($class, $field) = @_;
return sub :lvalue {
if (want 'LVALUE') {
my $caller = caller;
require Carp;
Carp::croak("'$caller' cannot alter the value of '$field' on ".
"objects of class '$class'");
}
tie my $tie, "Class::Accessor::Lvalue::Tied" => $field, @_;
$tie;
};
}
sub make_wo_accessor {
my($class, $field) = @_;
return sub :lvalue {
unless (want 'LVALUE') {
my $caller = caller;
require Carp;
Carp::croak("'$caller' cannot access the value of '$field' on ".
"objects of class '$class'");
}
tie my $tie, "Class::Accessor::Lvalue::Tied" => $field, @_;
$tie;
};
}
package Class::Accessor::Lvalue::Tied;
sub TIESCALAR { shift; bless [@_] }
sub STORE {
my ($field, $self) = @{ shift() };
$self->set( $field, @_ );
}
sub FETCH {
my ($field, $self) = @{ shift() };
$self->get( $field );
}
1;
__END__
=head1 NAME
Class::Accessor::Lvalue - create Lvalue accessors
=head1 SYNOPSIS
package Foo;
use base qw( Class::Accessor::Lvalue );
__PACKAGE__->mk_accessors(qw( bar ))
my $foo = Foo->new;
$foo->bar = 42;
print $foo->bar; # prints 42
=head1 DESCRIPTION
This module subclasses L<Class::Accessor> in order to provide lvalue
accessor makers.
=head1 CAVEATS
=over
=item
Though L<Class::Accessor> mutators allows for the setting of multiple
values to an attribute, the mutators that this module creates handle
single scalar values only. This should not be too much of a
hinderance as you can still explicitly use an anonymous array.
=item
Due to the hoops we have to jump through to preserve the
Class::Accessor ->get and ->set behaviour this module is potentially
slow. Should you not need the flexibility granted by the ->get and
->set methods, it's highly reccomended that you use
L<Class::Accessor::Lvalue::Fast> which is simpler and much faster.
=back
=head1 AUTHOR
Richard Clamp <richardc@unixbeard.net> with many thanks to Yuval
Kogman for helping with the groovy lvalue tie magic used in the main
class.
=head1 COPYRIGHT
Copyright (C) 2003 Richard Clamp. All Rights Reserved.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=head1 SEE ALSO
L<Class::Accessor>, L<Class::Accessor::Lvalue::Fast>
=cut
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