X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMooseX%2FStorage%2FEngine.pm;h=ec96c707c7a318aa94ad37aaf8b37fcfd00f7ec9;hb=45d9a73cb319d9cd4d3e30d07526d72cb3e11ad2;hp=7f3bbb4cce6e6252fd24feda7bfe2c99bffa61f3;hpb=ba5bba75ba0c4f8af075e95ce3b00e5376bedf5c;p=gitmo%2FMooseX-Storage.git

diff --git a/lib/MooseX/Storage/Engine.pm b/lib/MooseX/Storage/Engine.pm
index 7f3bbb4..ec96c70 100644
--- a/lib/MooseX/Storage/Engine.pm
+++ b/lib/MooseX/Storage/Engine.pm
@@ -2,14 +2,20 @@
 package MooseX::Storage::Engine;
 use Moose;
 
-our $VERSION = '0.01';
+our $VERSION = '0.02';
 
 # the class marker when 
 # serializing an object. 
 our $CLASS_MARKER = '__CLASS__';
 
 has 'storage' => (
-    is      => 'rw',
+    is      => 'ro',
+    isa     => 'HashRef',
+    default => sub {{}}
+);
+
+has 'seen' => (
+    is      => 'ro',
     isa     => 'HashRef',
     default => sub {{}}
 );
@@ -21,6 +27,11 @@ has 'class'  => (is => 'rw', isa => 'Str');
 
 sub collapse_object {
 	my $self = shift;
+
+	# NOTE:
+	# mark the root object as seen ...
+	$self->seen->{$self->object} = undef;
+	
     $self->map_attributes('collapse_attribute');
     $self->storage->{$CLASS_MARKER} = $self->object->meta->name;    
 	return $self->storage;
@@ -28,6 +39,11 @@ sub collapse_object {
 
 sub expand_object {
     my ($self, $data) = @_;
+    
+	# NOTE:
+	# mark the root object as seen ...
+	$self->seen->{$data} = undef;    
+    
     $self->map_attributes('expand_attribute', $data);
 	return $self->storage;    
 }
@@ -47,6 +63,14 @@ sub expand_attribute {
 sub collapse_attribute_value {
     my ($self, $attr)  = @_;
 	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)
@@ -58,6 +82,12 @@ sub collapse_attribute_value {
 
 sub expand_attribute_value {
     my ($self, $attr, $value)  = @_;
+
+	# 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);
@@ -65,12 +95,40 @@ sub expand_attribute_value {
 	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(" 
+                 . ($attr->associated_metaclass->name) . ").attr("
+                 . ($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(" 
+             . ($attr->associated_metaclass->name) . ").attr("
+             . ($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;
 }
 
@@ -170,7 +228,7 @@ my %TYPES = (
     #'CodeRef' => {
     #    expand   => sub {}, # use eval ...
     #    collapse => sub {}, # use B::Deparse ...        
-    #}       
+    #} 
 );
 
 sub add_custom_type_handler {
@@ -233,12 +291,12 @@ __END__
 
 =head1 NAME
 
-MooseX::Storage::Engine
-
-=head1 SYNOPSIS
+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
@@ -251,6 +309,8 @@ MooseX::Storage::Engine
 
 =item B<storage>
 
+=item B<seen>
+
 =back
 
 =head2 API
@@ -275,6 +335,10 @@ MooseX::Storage::Engine
 
 =item B<expand_attribute_value>
 
+=item B<check_for_cycle_in_collapse>
+
+=item B<check_for_cycle_in_expansion>
+
 =item B<map_attributes>
 
 =back