adding to changelog and changing versions

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

diff --git a/lib/Class/MOP/Class.pm b/lib/Class/MOP/Class.pm
index d0bf82a..06d6fcb 100644 (file)
--- a/lib/Class/MOP/Class.pm
+++ b/lib/Class/MOP/Class.pm
@@ -12,7 +12,7 @@ use Carp         'confess';
 use Scalar::Util 'blessed', 'reftype', 'weaken';
 use Sub::Name    'subname';
 
-our $VERSION   = '0.26';
+our $VERSION   = '0.28';
 our $AUTHORITY = 'cpan:STEVAN';
 
 use base 'Class::MOP::Module';
@@ -386,35 +386,72 @@ sub clone_instance {
     my $meta_instance = $class->get_meta_instance();
     my $clone = $meta_instance->clone_instance($instance);
     foreach my $attr ($class->compute_all_applicable_attributes()) {
-        if (exists $params{$attr->init_arg}) {
-            $meta_instance->set_slot_value($clone, $attr->name, $params{$attr->init_arg});
+        if ( defined( my $init_arg = $attr->init_arg ) ) {
+            if (exists $params{$init_arg}) {
+                $attr->set_value($clone, $params{$init_arg});
+            }
         }
     }
     return $clone;
 }
 
 sub rebless_instance {
-    my ($self, $instance, $new_metaclass) = @_;
+    my ($self, $instance) = @_;
 
-    # it's okay (expected, even) to pass in a package name
-    unless (blessed $new_metaclass) {
-        $new_metaclass = $self->initialize($new_metaclass);
+    my $old_metaclass;
+    if ($instance->can('meta')) {
+        ($instance->meta->isa('Class::MOP::Class'))
+            || confess 'Cannot rebless instance if ->meta is not an instance of Class::MOP::Class';
+        $old_metaclass = $instance->meta;
+    }
+    else {
+        $old_metaclass = $self->initialize(blessed($instance));
     }
 
-    # make sure we're reblessing into a subclass
-    my $is_subclass = 0;
-    for my $superclass ($new_metaclass->linearized_isa) {
-        if ($superclass eq $self->name) {
-            $is_subclass = 1;
-            last;
+    my $meta_instance = $self->get_meta_instance();
+
+    $self->name->isa($old_metaclass->name)
+        || confess "You may rebless only into a subclass of (". $old_metaclass->name ."), of which (". $self->name .") isn't.";
+
+    # rebless!
+    $meta_instance->rebless_instance_structure($instance, $self);
+
+    my %params;
+
+    foreach my $attr ( $self->compute_all_applicable_attributes ) {
+        if ( $attr->has_value($instance) ) {
+            if ( defined( my $init_arg = $attr->init_arg ) ) {
+                $params{$init_arg} = $attr->get_value($instance);
+            } else {
+                $attr->set_value($instance);
+            }
         }
     }
 
-    $is_subclass
-        || confess "You may rebless only into a subclass. (". $new_metaclass->name .") is not a subclass of (". $self->name .").";
+    foreach my $attr ($self->compute_all_applicable_attributes) {
+        $attr->initialize_instance_slot($meta_instance, $instance, \%params);
+    }
+}
 
-    my $meta_instance = $self->get_meta_instance();
-    return $meta_instance->rebless_instance_structure($instance, $new_metaclass);
+sub get_attribute_values {
+    my ($self, $instance) = @_;
+
+    return +{
+        map { $_->name => $_->get_value($instance) }
+            grep { $_->has_value($instance) }
+                $self->compute_all_applicable_attributes
+    };
+}
+
+sub get_init_args {
+    my ($self, $instance) = @_;
+
+    return +{
+        map { $_->init_arg => $_->get_value($instance) }
+            grep { $_->has_value($instance) }
+                grep { defined($_->init_arg) } 
+                    $self->compute_all_applicable_attributes
+    };
 }
 
 # Inheritance
@@ -1109,6 +1146,25 @@ shallow cloning is outside the scope of the meta-object protocol. I
 think Yuval "nothingmuch" Kogman put it best when he said that cloning
 is too I<context-specific> to be part of the MOP.
 
+=item B<get_attribute_values($instance)>
+
+Returns the values of the C<$instance>'s fields keyed by the attribute names.
+
+=item B<get_init_args($instance)>
+
+Returns a hash reference where the keys are all the attributes' C<init_arg>s
+and the values are the instance's fields. Attributes without an C<init_arg>
+will be skipped.
+
+=item B<rebless_instance($instance)>
+
+This will change the class of C<$instance> to the class of the invoking
+C<Class::MOP::Class>. You may only rebless the instance to a subclass of
+itself. This limitation may be relaxed in the future.
+
+This can be useful in a number of situations, such as when you are writing
+a program that doesn't know everything at object construction time.
+
 =back
 
 =head2 Informational