[gitmo/MooseX-Storage.git] / lib / MooseX / Storage / Engine.pm


package MooseX::Storage::Engine;
use Moose;

our $VERSION   = '0.02';
our $AUTHORITY = 'cpan:STEVAN';

# the class marker when 
# serializing an object. 
our $CLASS_MARKER = '__CLASS__';

has 'storage' => (
    is      => 'ro',
    isa     => 'HashRef',
    default => sub {{}}
);

has 'seen' => (
    is      => 'ro',
    isa     => 'HashRef',
    default => sub {{}}
);

has 'object' => (is => 'rw', isa => 'Object');
has 'class'  => (is => 'rw', isa => 'Str');

## this is the API used by other modules ...

sub collapse_object {
    my ( $self, %options ) = @_;

	# NOTE:
	# mark the root object as seen ...
	$self->seen->{$self->object} = undef;
	
    $self->map_attributes('collapse_attribute', \%options);
    $self->storage->{$CLASS_MARKER} = $self->object->meta->identifier;    
	return $self->storage;
}

sub expand_object {
    my ($self, $data, %options) = @_;
    
    $options{check_version}   = 1 unless exists $options{check_version};
    $options{check_authority} = 1 unless exists $options{check_authority};   
    
	# NOTE:
	# mark the root object as seen ...
	$self->seen->{$data} = undef;    
    
    $self->map_attributes('expand_attribute', $data, \%options);
	return $self->storage;    
}

## this is the internal API ...

sub collapse_attribute {
    my ($self, $attr, $options)  = @_;
    $self->storage->{$attr->name} = $self->collapse_attribute_value($attr, $options) || return;
}

sub expand_attribute {
    my ($self, $attr, $data, $options)  = @_;
    $self->storage->{$attr->name} = $self->expand_attribute_value($attr, $data->{$attr->name}, $options) || return;
}

sub collapse_attribute_value {
    my ($self, $attr, $options)  = @_;
	my $value = $attr->get_value($self->object);
	
	# NOTE:
	# this might not be enough, we might 
	# need to make it possible for the 
	# cycle checker to return the value
    $self->check_for_cycle_in_collapse($attr, $value)
        if ref $value;
	
    if (defined $value && $attr->has_type_constraint) {
        my $type_converter = $self->find_type_handler($attr->type_constraint);
        (defined $type_converter)
            || confess "Cannot convert " . $attr->type_constraint->name;
        $value = $type_converter->{collapse}->($value, $options);
    }
	return $value;
}

sub expand_attribute_value {
    my ($self, $attr, $value, $options)  = @_;

	# NOTE:
	# (see comment in method above ^^)
    $self->check_for_cycle_in_expansion($attr, $value) 
        if ref $value;    
    
    if (defined $value && $attr->has_type_constraint) {
        my $type_converter = $self->find_type_handler($attr->type_constraint);
        $value = $type_converter->{expand}->($value, $options);
    }
	return $value;
}

# NOTE:
# possibly these two methods will 
# be used by a cycle supporting 
# engine. However, I am not sure 
# if I can make a cycle one work 
# anyway.

sub check_for_cycle_in_collapse {
    my ($self, $attr, $value) = @_;
    (!exists $self->seen->{$value})
        || confess "Basic Engine does not support cycles in class(" 
                 . ($attr->associated_class->name) . ").attr("
                 . ($attr->name) . ") with $value";
    $self->seen->{$value} = undef;
}

sub check_for_cycle_in_expansion {
    my ($self, $attr, $value) = @_;
    (!exists $self->seen->{$value})
    || confess "Basic Engine does not support cycles in class(" 
             . ($attr->associated_class->name) . ").attr("
             . ($attr->name) . ") with $value";
    $self->seen->{$value} = undef;
}

# util methods ...

sub map_attributes {
    my ($self, $method_name, @args) = @_;
    map { 
        $self->$method_name($_, @args) 
    } grep {
        # Skip our special skip attribute :)
        !$_->isa('MooseX::Storage::Meta::Attribute::DoNotSerialize')
    } ($self->object || $self->class)->meta->compute_all_applicable_attributes;
}

## ------------------------------------------------------------------
## This is all the type handler stuff, it is in a state of flux
## right now, so this may change, or it may just continue to be 
## improved upon. Comments and suggestions are welcomed.
## ------------------------------------------------------------------

# NOTE:
# these are needed by the 
# ArrayRef and HashRef handlers
# below, so I need easy access 
my %OBJECT_HANDLERS = (
    expand => sub {
        my ($data, $options) = @_;   
        (exists $data->{$CLASS_MARKER})
            || confess "Serialized item has no class marker";
        # check the class more thoroughly here ...
        my ($class, $version, $authority) = (split '-' => $data->{$CLASS_MARKER});
        my $meta = eval { $class->meta };
        confess "Class ($class) is not loaded, cannot unpack" if $@;     
        
        if ($options->{check_version}) {
            my $meta_version = $meta->version;
            if (defined $meta_version && $version) {            
                if ($options->{check_version} eq 'allow_less_than') {
                    ($meta_version <= $version)
                        || confess "Class ($class) versions is not less than currently available." 
                                 . " got=($version) available=($meta_version)";                
                }
                elsif ($options->{check_version} eq 'allow_greater_than') {
                    ($meta->version >= $version)
                        || confess "Class ($class) versions is not greater than currently available." 
                                 . " got=($version) available=($meta_version)";                
                }            
                else {
                    ($meta->version == $version)
                        || confess "Class ($class) versions don't match." 
                                 . " got=($version) available=($meta_version)";
                }
            }
        }
        
        if ($options->{check_authority}) {
            my $meta_authority = $meta->authority;
            ($meta->authority eq $authority)
                || confess "Class ($class) authorities don't match." 
                         . " got=($authority) available=($meta_authority)"
                if defined $meta_authority && defined $authority;            
        }
            
        # all is well ...
        $class->unpack($data, %$options);
    },
    collapse => sub {
        my ( $obj, $options ) = @_;
#        ($obj->can('does') && $obj->does('MooseX::Storage::Basic'))
#            || confess "Bad object ($obj) does not do MooseX::Storage::Basic role";
        ($obj->can('pack'))
            || confess "Object does not have a &pack method, cannot collapse";
        $obj->pack(%$options);
    },
);


my %TYPES = (
    # These are boring ones, so they use the identity function ...
    'Int'      => { expand => sub { shift }, collapse => sub { shift } },
    'Num'      => { expand => sub { shift }, collapse => sub { shift } },
    'Str'      => { expand => sub { shift }, collapse => sub { shift } },
    # These are the trickier ones, (see notes)
    # NOTE:
    # Because we are nice guys, we will check 
    # your ArrayRef and/or HashRef one level 
    # down and inflate any objects we find. 
    # But this is where it ends, it is too
    # expensive to try and do this any more  
    # recursively, when it is probably not 
    # nessecary in most of the use cases.
    # However, if you need more then this, subtype 
    # and add a custom handler.    
    'ArrayRef' => { 
        expand => sub {
            my ( $array, @args ) = @_;
            foreach my $i (0 .. $#{$array}) {
                next unless ref($array->[$i]) eq 'HASH' 
                         && exists $array->[$i]->{$CLASS_MARKER};
                $array->[$i] = $OBJECT_HANDLERS{expand}->($array->[$i], @args);
            }
            $array;
        }, 
        collapse => sub {
            my ( $array, @args ) = @_;
            # NOTE:         
            # we need to make a copy cause
            # otherwise it will affect the 
            # other real version.
            [ map {
                blessed($_)
                    ? $OBJECT_HANDLERS{collapse}->($_, @args)
                    : $_
            } @$array ] 
        } 
    },
    'HashRef'  => { 
        expand   => sub {
            my ( $hash, @args ) = @_;
            foreach my $k (keys %$hash) {
                next unless ref($hash->{$k}) eq 'HASH' 
                         && exists $hash->{$k}->{$CLASS_MARKER};
                $hash->{$k} = $OBJECT_HANDLERS{expand}->($hash->{$k}, @args);
            }
            $hash;            
        }, 
        collapse => sub {
            my ( $hash, @args ) = @_;
            # NOTE:         
            # we need to make a copy cause
            # otherwise it will affect the 
            # other real version.
            +{ map {
                blessed($hash->{$_})
                    ? ($_ => $OBJECT_HANDLERS{collapse}->($hash->{$_}, @args))
                    : ($_ => $hash->{$_})
            } keys %$hash }            
        } 
    },
    'Object'   => \%OBJECT_HANDLERS,
    # NOTE:
    # The sanity of enabling this feature by 
    # default is very questionable.
    # - SL
    #'CodeRef' => {
    #    expand   => sub {}, # use eval ...
    #    collapse => sub {}, # use B::Deparse ...        
    #} 
);

sub add_custom_type_handler {
    my ($class, $type_name, %handlers) = @_;
    (exists $handlers{expand} && exists $handlers{collapse})
        || confess "Custom type handlers need an expand *and* a collapse method";
    $TYPES{$type_name} = \%handlers;
}

sub remove_custom_type_handler {
    my ($class, $type_name) = @_;
    delete $TYPES{$type_name} if exists $TYPES{$type_name};
}

sub find_type_handler {
    my ($self, $type_constraint) = @_;
    
    # this should handle most type usages
    # since they they are usually just 
    # the standard set of built-ins
    return $TYPES{$type_constraint->name} 
        if exists $TYPES{$type_constraint->name};
      
    # the next possibility is they are 
    # a subtype of the built-in types, 
    # in which case this will DWIM in 
    # most cases. It is probably not 
    # 100% ideal though, but until I 
    # come up with a decent test case 
    # it will do for now.
    foreach my $type (keys %TYPES) {
        return $TYPES{$type} 
            if $type_constraint->is_subtype_of($type);
    }
    
    # NOTE:
    # the reason the above will work has to 
    # do with the fact that custom subtypes
    # are mostly used for validation of 
    # the guts of a type, and not for some
    # weird structural thing which would 
    # need to be accomidated by the serializer.
    # Of course, mst or phaylon will probably  
    # do something to throw this assumption 
    # totally out the door ;)
    # - SL
    
    # NOTE:
    # if this method hasnt returned by now
    # then we have no been able to find a 
    # type constraint handler to match 
    confess "Cannot handle type constraint (" . $type_constraint->name . ")";    
}

1;

__END__

=pod

=head1 NAME

MooseX::Storage::Engine - The meta-engine to handle collapsing and expanding objects

=head1 DESCRIPTION

No user serviceable parts inside. If you really want to know, read the source :)

=head1 METHODS

=head2 Accessors

=over 4

=item B<class>

=item B<object>

=item B<storage>

=item B<seen>

=back

=head2 API

=over 4

=item B<expand_object>

=item B<collapse_object>

=back

=head2 ...

=over 4

=item B<collapse_attribute>

=item B<collapse_attribute_value>

=item B<expand_attribute>

=item B<expand_attribute_value>

=item B<check_for_cycle_in_collapse>

=item B<check_for_cycle_in_expansion>

=item B<map_attributes>

=back

=head2 Type Constraint Handlers

=over 4

=item B<find_type_handler>

=item B<add_custom_type_handler>

=item B<remove_custom_type_handler>

=back

=head2 Introspection

=over 4

=item B<meta>

=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

Chris Prather E<lt>chris.prather@iinteractive.comE<gt>

Stevan Little E<lt>stevan.little@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
Commit	Line	Data
e59193fb	1
	2	package MooseX::Storage::Engine;
	3	use Moose;
	4
69b45b7d	5	our $VERSION = '0.02';
69b45b7d	6	our $AUTHORITY = 'cpan:STEVAN';
ba5bba75	7
	8	# the class marker when
	9	# serializing an object.
	10	our $CLASS_MARKER = '__CLASS__';
	11
e59193fb	12	has 'storage' => (
7eb5dc63	13	is => 'ro',
	14	isa => 'HashRef',
	15	default => sub {{}}
	16	);
	17
	18	has 'seen' => (
	19	is => 'ro',
e9739624	20	isa => 'HashRef',
e59193fb	21	default => sub {{}}
	22	);
	23
e9739624	24	has 'object' => (is => 'rw', isa => 'Object');
e9739624	25	has 'class' => (is => 'rw', isa => 'Str');
e59193fb	26
e9739624	27	## this is the API used by other modules ...
e59193fb	28
e59193fb	29	sub collapse_object {
34dcaa5d	30	my ( $self, %options ) = @_;
7eb5dc63	31
	32	# NOTE:
	33	# mark the root object as seen ...
	34	$self->seen->{$self->object} = undef;
	35
34dcaa5d	36	$self->map_attributes('collapse_attribute', \%options);
c1830046	37	$self->storage->{$CLASS_MARKER} = $self->object->meta->identifier;
e59193fb	38	return $self->storage;
	39	}
	40
e9739624	41	sub expand_object {
219c1cc5	42	my ($self, $data, %options) = @_;
	43
	44	$options{check_version} = 1 unless exists $options{check_version};
	45	$options{check_authority} = 1 unless exists $options{check_authority};
7eb5dc63	46
	47	# NOTE:
	48	# mark the root object as seen ...
	49	$self->seen->{$data} = undef;
	50
219c1cc5	51	$self->map_attributes('expand_attribute', $data, \%options);
e9739624	52	return $self->storage;
e59193fb	53	}
e59193fb	54
e9739624	55	## this is the internal API ...
	56
	57	sub collapse_attribute {
f6e1331f	58	my ($self, $attr, $options) = @_;
f6e1331f	59	$self->storage->{$attr->name} = $self->collapse_attribute_value($attr, $options) \|\| return;
e9739624	60	}
	61
	62	sub expand_attribute {
219c1cc5	63	my ($self, $attr, $data, $options) = @_;
219c1cc5	64	$self->storage->{$attr->name} = $self->expand_attribute_value($attr, $data->{$attr->name}, $options) \|\| return;
e59193fb	65	}
e59193fb	66
e9739624	67	sub collapse_attribute_value {
f6e1331f	68	my ($self, $attr, $options) = @_;
e9739624	69	my $value = $attr->get_value($self->object);
7eb5dc63	70
b430caa3	71	# NOTE:
	72	# this might not be enough, we might
	73	# need to make it possible for the
	74	# cycle checker to return the value
34dcaa5d	75	$self->check_for_cycle_in_collapse($attr, $value)
7eb5dc63	76	if ref $value;
7eb5dc63	77
e9739624	78	if (defined $value && $attr->has_type_constraint) {
3db8f791	79	my $type_converter = $self->find_type_handler($attr->type_constraint);
e9739624	80	(defined $type_converter)
e9739624	81	\|\| confess "Cannot convert " . $attr->type_constraint->name;
f6e1331f	82	$value = $type_converter->{collapse}->($value, $options);
e9739624	83	}
	84	return $value;
	85	}
	86
	87	sub expand_attribute_value {
219c1cc5	88	my ($self, $attr, $value, $options) = @_;
7eb5dc63	89
b430caa3	90	# NOTE:
b430caa3	91	# (see comment in method above ^^)
45d9a73c	92	$self->check_for_cycle_in_expansion($attr, $value)
7eb5dc63	93	if ref $value;
7eb5dc63	94
e9739624	95	if (defined $value && $attr->has_type_constraint) {
3db8f791	96	my $type_converter = $self->find_type_handler($attr->type_constraint);
219c1cc5	97	$value = $type_converter->{expand}->($value, $options);
e9739624	98	}
	99	return $value;
	100	}
	101
b430caa3	102	# NOTE:
	103	# possibly these two methods will
	104	# be used by a cycle supporting
	105	# engine. However, I am not sure
	106	# if I can make a cycle one work
	107	# anyway.
e9739624	108
7eb5dc63	109	sub check_for_cycle_in_collapse {
45d9a73c	110	my ($self, $attr, $value) = @_;
7eb5dc63	111	(!exists $self->seen->{$value})
45d9a73c	112	\|\| confess "Basic Engine does not support cycles in class("
c1830046	113	. ($attr->associated_class->name) . ").attr("
45d9a73c	114	. ($attr->name) . ") with $value";
7eb5dc63	115	$self->seen->{$value} = undef;
	116	}
	117
	118	sub check_for_cycle_in_expansion {
45d9a73c	119	my ($self, $attr, $value) = @_;
7eb5dc63	120	(!exists $self->seen->{$value})
45d9a73c	121	\|\| confess "Basic Engine does not support cycles in class("
c1830046	122	. ($attr->associated_class->name) . ").attr("
45d9a73c	123	. ($attr->name) . ") with $value";
7eb5dc63	124	$self->seen->{$value} = undef;
	125	}
	126
b430caa3	127	# util methods ...
b430caa3	128
e9739624	129	sub map_attributes {
	130	my ($self, $method_name, @args) = @_;
	131	map {
	132	$self->$method_name($_, @args)
b430caa3	133	} grep {
	134	# Skip our special skip attribute :)
	135	!$_->isa('MooseX::Storage::Meta::Attribute::DoNotSerialize')
e9739624	136	} ($self->object \|\| $self->class)->meta->compute_all_applicable_attributes;
e59193fb	137	}
e59193fb	138
913d96dd	139	## ------------------------------------------------------------------
3db8f791	140	## This is all the type handler stuff, it is in a state of flux
	141	## right now, so this may change, or it may just continue to be
	142	## improved upon. Comments and suggestions are welcomed.
913d96dd	143	## ------------------------------------------------------------------
	144
	145	# NOTE:
	146	# these are needed by the
	147	# ArrayRef and HashRef handlers
	148	# below, so I need easy access
	149	my %OBJECT_HANDLERS = (
	150	expand => sub {
219c1cc5	151	my ($data, $options) = @_;
ba5bba75	152	(exists $data->{$CLASS_MARKER})
913d96dd	153	\|\| confess "Serialized item has no class marker";
c1830046	154	# check the class more thoroughly here ...
	155	my ($class, $version, $authority) = (split '-' => $data->{$CLASS_MARKER});
	156	my $meta = eval { $class->meta };
219c1cc5	157	confess "Class ($class) is not loaded, cannot unpack" if $@;
	158
	159	if ($options->{check_version}) {
	160	my $meta_version = $meta->version;
	161	if (defined $meta_version && $version) {
	162	if ($options->{check_version} eq 'allow_less_than') {
	163	($meta_version <= $version)
	164	\|\| confess "Class ($class) versions is not less than currently available."
	165	. " got=($version) available=($meta_version)";
	166	}
	167	elsif ($options->{check_version} eq 'allow_greater_than') {
	168	($meta->version >= $version)
	169	\|\| confess "Class ($class) versions is not greater than currently available."
	170	. " got=($version) available=($meta_version)";
	171	}
	172	else {
	173	($meta->version == $version)
	174	\|\| confess "Class ($class) versions don't match."
	175	. " got=($version) available=($meta_version)";
	176	}
	177	}
	178	}
	179
	180	if ($options->{check_authority}) {
	181	my $meta_authority = $meta->authority;
	182	($meta->authority eq $authority)
	183	\|\| confess "Class ($class) authorities don't match."
	184	. " got=($authority) available=($meta_authority)"
	185	if defined $meta_authority && defined $authority;
	186	}
	187
c1830046	188	# all is well ...
34dcaa5d	189	$class->unpack($data, %$options);
913d96dd	190	},
913d96dd	191	collapse => sub {
34dcaa5d	192	my ( $obj, $options ) = @_;
c4a322ec	193	# ($obj->can('does') && $obj->does('MooseX::Storage::Basic'))
c4a322ec	194	# \|\| confess "Bad object ($obj) does not do MooseX::Storage::Basic role";
1c6ac775	195	($obj->can('pack'))
1c6ac775	196	\|\| confess "Object does not have a &pack method, cannot collapse";
34dcaa5d	197	$obj->pack(%$options);
913d96dd	198	},
	199	);
	200
	201
e59193fb	202	my %TYPES = (
3db8f791	203	# These are boring ones, so they use the identity function ...
e9739624	204	'Int' => { expand => sub { shift }, collapse => sub { shift } },
	205	'Num' => { expand => sub { shift }, collapse => sub { shift } },
	206	'Str' => { expand => sub { shift }, collapse => sub { shift } },
3db8f791	207	# These are the trickier ones, (see notes)
	208	# NOTE:
	209	# Because we are nice guys, we will check
	210	# your ArrayRef and/or HashRef one level
	211	# down and inflate any objects we find.
	212	# But this is where it ends, it is too
	213	# expensive to try and do this any more
	214	# recursively, when it is probably not
	215	# nessecary in most of the use cases.
	216	# However, if you need more then this, subtype
	217	# and add a custom handler.
913d96dd	218	'ArrayRef' => {
e9739624	219	expand => sub {
34dcaa5d	220	my ( $array, @args ) = @_;
913d96dd	221	foreach my $i (0 .. $#{$array}) {
913d96dd	222	next unless ref($array->[$i]) eq 'HASH'
ba5bba75	223	&& exists $array->[$i]->{$CLASS_MARKER};
34dcaa5d	224	$array->[$i] = $OBJECT_HANDLERS{expand}->($array->[$i], @args);
913d96dd	225	}
	226	$array;
	227	},
34dcaa5d	228	collapse => sub {
34dcaa5d	229	my ( $array, @args ) = @_;
913d96dd	230	# NOTE:
	231	# we need to make a copy cause
	232	# otherwise it will affect the
	233	# other real version.
	234	[ map {
	235	blessed($_)
34dcaa5d	236	? $OBJECT_HANDLERS{collapse}->($_, @args)
913d96dd	237	: $_
	238	} @$array ]
	239	}
	240	},
	241	'HashRef' => {
3db8f791	242	expand => sub {
34dcaa5d	243	my ( $hash, @args ) = @_;
3db8f791	244	foreach my $k (keys %$hash) {
3db8f791	245	next unless ref($hash->{$k}) eq 'HASH'
ba5bba75	246	&& exists $hash->{$k}->{$CLASS_MARKER};
34dcaa5d	247	$hash->{$k} = $OBJECT_HANDLERS{expand}->($hash->{$k}, @args);
3db8f791	248	}
	249	$hash;
	250	},
	251	collapse => sub {
34dcaa5d	252	my ( $hash, @args ) = @_;
3db8f791	253	# NOTE:
	254	# we need to make a copy cause
	255	# otherwise it will affect the
	256	# other real version.
	257	+{ map {
95f31c36	258	blessed($hash->{$_})
f6e1331f	259	? ($_ => $OBJECT_HANDLERS{collapse}->($hash->{$_}, @args))
3db8f791	260	: ($_ => $hash->{$_})
	261	} keys %$hash }
	262	}
e1bb45ff	263	},
913d96dd	264	'Object' => \%OBJECT_HANDLERS,
e1bb45ff	265	# NOTE:
	266	# The sanity of enabling this feature by
	267	# default is very questionable.
	268	# - SL
	269	#'CodeRef' => {
	270	# expand => sub {}, # use eval ...
	271	# collapse => sub {}, # use B::Deparse ...
7eb5dc63	272	#}
e59193fb	273	);
e59193fb	274
3db8f791	275	sub add_custom_type_handler {
	276	my ($class, $type_name, %handlers) = @_;
	277	(exists $handlers{expand} && exists $handlers{collapse})
	278	\|\| confess "Custom type handlers need an expand and a collapse method";
	279	$TYPES{$type_name} = \%handlers;
	280	}
	281
	282	sub remove_custom_type_handler {
	283	my ($class, $type_name) = @_;
	284	delete $TYPES{$type_name} if exists $TYPES{$type_name};
	285	}
	286
	287	sub find_type_handler {
e59193fb	288	my ($self, $type_constraint) = @_;
e1bb45ff	289
	290	# this should handle most type usages
	291	# since they they are usually just
	292	# the standard set of built-ins
	293	return $TYPES{$type_constraint->name}
	294	if exists $TYPES{$type_constraint->name};
	295
	296	# the next possibility is they are
	297	# a subtype of the built-in types,
	298	# in which case this will DWIM in
	299	# most cases. It is probably not
	300	# 100% ideal though, but until I
	301	# come up with a decent test case
	302	# it will do for now.
e59193fb	303	foreach my $type (keys %TYPES) {
	304	return $TYPES{$type}
	305	if $type_constraint->is_subtype_of($type);
	306	}
e1bb45ff	307
	308	# NOTE:
	309	# the reason the above will work has to
	310	# do with the fact that custom subtypes
	311	# are mostly used for validation of
	312	# the guts of a type, and not for some
	313	# weird structural thing which would
	314	# need to be accomidated by the serializer.
	315	# Of course, mst or phaylon will probably
	316	# do something to throw this assumption
	317	# totally out the door ;)
	318	# - SL
	319
e9739624	320	# NOTE:
	321	# if this method hasnt returned by now
	322	# then we have no been able to find a
	323	# type constraint handler to match
	324	confess "Cannot handle type constraint (" . $type_constraint->name . ")";
e59193fb	325	}
	326
	327	1;
e9739624	328
	329	__END__
	330
	331	=pod
	332
ec9c1923	333	=head1 NAME
ec9c1923	334
1390c23d	335	MooseX::Storage::Engine - The meta-engine to handle collapsing and expanding objects
ec9c1923	336
	337	=head1 DESCRIPTION
	338
1390c23d	339	No user serviceable parts inside. If you really want to know, read the source :)
1390c23d	340
ec9c1923	341	=head1 METHODS
	342
	343	=head2 Accessors
	344
	345	=over 4
	346
	347	=item B<class>
	348
	349	=item B<object>
	350
	351	=item B<storage>
	352
b430caa3	353	=item B<seen>
b430caa3	354
ec9c1923	355	=back
	356
	357	=head2 API
	358
	359	=over 4
	360
	361	=item B<expand_object>
	362
	363	=item B<collapse_object>
	364
	365	=back
	366
	367	=head2 ...
	368
	369	=over 4
	370
	371	=item B<collapse_attribute>
	372
	373	=item B<collapse_attribute_value>
	374
	375	=item B<expand_attribute>
	376
	377	=item B<expand_attribute_value>
	378
b430caa3	379	=item B<check_for_cycle_in_collapse>
	380
	381	=item B<check_for_cycle_in_expansion>
	382
ec9c1923	383	=item B<map_attributes>
ec9c1923	384
3db8f791	385	=back
	386
	387	=head2 Type Constraint Handlers
	388
	389	=over 4
	390
	391	=item B<find_type_handler>
	392
	393	=item B<add_custom_type_handler>
	394
	395	=item B<remove_custom_type_handler>
ec9c1923	396
	397	=back
	398
	399	=head2 Introspection
	400
	401	=over 4
	402
	403	=item B<meta>
	404
	405	=back
	406
	407	=head1 BUGS
	408
	409	All complex software has bugs lurking in it, and this module is no
	410	exception. If you find a bug please either email me, or add the bug
	411	to cpan-RT.
	412
	413	=head1 AUTHOR
	414
	415	Chris Prather E<lt>chris.prather@iinteractive.comE<gt>
	416
	417	Stevan Little E<lt>stevan.little@iinteractive.comE<gt>
	418
	419	=head1 COPYRIGHT AND LICENSE
	420
	421	Copyright 2007 by Infinity Interactive, Inc.
	422
	423	L<http://www.iinteractive.com>
	424
	425	This library is free software; you can redistribute it and/or modify
	426	it under the same terms as Perl itself.
	427
e9739624	428	=cut
	429
	430
ec9c1923	431