#
# $Id: YAML.pm,v 0.3 2006/03/22 22:10:28 dankogai Exp $
#
package Tie::YAML;
use strict;
use warnings;
our $VERSION = sprintf "%d.%02d", q$Revision: 0.3 $ =~ /(\d+)/g;
use base 'Tie::SaveLater';
use Carp;
use YAML;
__PACKAGE__->make_subclasses;
sub load{
my $class = shift;
my $filename = shift;
open my $fh, "<:raw", $filename or croak "$filename: $!";
local $/; # slurp;
my $yaml = <$fh>;
close $fh;
return Load($yaml);
}
sub save{
my $self = shift;
my $filename = $self->filename;
open my $fh, ">:raw", $filename or croak "$filename: $!";
print $fh Dump(damn_scalar($self));
close $fh;
return 1;
}
sub damn_scalar { # iff necessary
return $_[0] unless ref($_[0]) =~ /::SCALAR$/;
return \do{ my $scalar = ${ $_[0] }}
}
1;
__END__
=head1 NAME
Tie::YAML - Stores your object when untied via YAML
=head1 SYNOPSIS
use Tie::YAML;
{
tie my $scalar => 'Tie::YAML', 'scalar.po';
$scalar = 42;
} # scalar is automatically saved as 'scalar.po'.
{
tie my @array => 'Tie::YAML', 'array.po';
@array = qw(Sun Mon Tue Wed Fri Sat);
} # array is automatically saved as 'array.po'.
{
tie my %hash => 'Tie::YAML', 'hash.po';
%hash = (Sun=>0, Mon=>1, Tue=>2, Wed=>3, Thu=>4, Fri=>5, Sat=>6);
} # hash is automatically saved as 'hash.po'.
{
tie my $object => 'Tie::YAML', 'object.po';
$object = bless { First => 'Dan', Last => 'Kogai' }, 'DANKOGAI';
} # You can save an object; just pass a scalar
{
tie my $object => 'Tie::YAML', 'object.po';
$object->{WIFE} = { First => 'Naomi', Last => 'Kogai' };
# you can save before you untie like this
tied($object)->save;
}
=head1 DESCRIPTION
Tie::YAML stores tied variables when untied. Usually that happens
when you variable is out of scope. You can of course explicitly untie
the variable or C<< tied($variable)->save >> but the whole idea is not
to forget to save it.
This module uses L<YAML> as its backend so it can store and
retrieve anything that L<YAML> can.
=head1 DEPENDENCIES
This module requires L<YAML>.
=head1 SEE ALSO
L<Tie::SaveLater>, L<Tie::DataDumper>, L<Tie::Storable>
L<perltie>, L<Tie::Scalar>, L<Tie::Array>, L<Tie::Hash>
=head1 BUGS
As of YAML 0.58, YAML cannot serialize a blessed scalar reference to
blessed scalar reference. For that reason, I had to implement a
funcition that looks like this.
sub damn_scalar { # iff necessary
return $_[0] unless ref($_[0]) =~ /::SCALAR$/;
return \do{ my $scalar = ${ $_[0] }}
}
Sigh.
=head1 AUTHOR
Dan Kogai, E<lt>dankogai@dan.co.jpE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2006 by Dan Kogai
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.8 or,
at your option, any later version of Perl 5 you may have available.
=cut