use Sub::Name 'subname';
use B 'svref_2object';
-our $VERSION = '0.02';
+our $VERSION = '0.03';
# Self-introspection
-sub meta { $_[0]->initialize($_[0]) }
+sub meta { Class::MOP::Class->initialize($_[0]) }
# Creation
my $class = shift;
my $package_name = shift;
(defined $package_name && $package_name)
- || confess "You must pass a package name";
+ || confess "You must pass a package name";
+ # make sure the package name is not blessed
+ $package_name = blessed($package_name) || $package_name;
return $METAS{$package_name} if exists $METAS{$package_name};
$METAS{$package_name} = $class->construct_class_instance($package_name, @_);
}
return $meta;
}
-# Instance Construction
+# Instance Construction & Cloning
+
sub construct_instance {
my ($class, %params) = @_;
my $instance = {};
- foreach my $attr (map { $_->{attribute} } $class->compute_all_applicable_attributes()) {
- # if the attr has an init_arg, use that, otherwise,
- # use the attributes name itself as the init_arg
+ foreach my $attr ($class->compute_all_applicable_attributes()) {
my $init_arg = $attr->has_init_arg() ? $attr->init_arg() : $attr->name;
# try to fetch the init arg from the %params ...
my $val;
$val = $params{$init_arg} if exists $params{$init_arg};
# if nothing was in the %params, we can use the
# attribute's default value (if it has one)
- $val ||= $attr->default($instance) if $attr->has_default();
- # now add this to the instance structure
+ $val ||= $attr->default($instance) if $attr->has_default();
$instance->{$attr->name} = $val;
}
return $instance;
}
+sub clone_instance {
+ my ($class, $self, %params) = @_;
+ (blessed($self))
+ || confess "You can only clone instances, \$self is not a blessed instance";
+ # NOTE:
+ # this should actually do a deep clone
+ # instead of this cheap hack. I will
+ # add that in later.
+ # (use the Class::Cloneable::Util code)
+ my $clone = { %{$self} };
+ foreach my $attr ($class->compute_all_applicable_attributes()) {
+ my $init_arg = $attr->has_init_arg() ? $attr->init_arg() : $attr->name;
+ # try to fetch the init arg from the %params ...
+ $clone->{$attr->name} = $params{$init_arg}
+ if exists $params{$init_arg};
+ }
+ return $clone;
+}
+
# Informational
sub name { $_[0]->{'$:package'} }
foreach my $attr_name ($meta->get_attribute_list()) {
next if exists $seen_attr{$attr_name};
$seen_attr{$attr_name}++;
- push @attrs => {
- name => $attr_name,
- class => $class,
- attribute => $meta->get_attribute($attr_name)
- };
+ push @attrs => $meta->get_attribute($attr_name);
}
}
return @attrs;
=back
-=head2 Object instance construction
-
-This method is used to construct an instace structure suitable for
-C<bless>-ing into your package of choice. It works in conjunction
-with the Attribute protocol to collect all applicable attributes.
+=head2 Object instance construction and cloning
-This method is B<entirely optional>, it is up to you whether you want
-to use it or not.
+These methods are B<entirely optional>, it is up to you whether you want
+to use them or not.
=over 4
=item B<construct_instance (%params)>
+This method is used to construct an instace structure suitable for
+C<bless>-ing into your package of choice. It works in conjunction
+with the Attribute protocol to collect all applicable attributes.
+
This will construct and instance using a HASH ref as storage
(currently only HASH references are supported). This will collect all
the applicable attributes and layout out the fields in the HASH ref,
in C<%params> or any default value or initializer found in the
attribute meta-object.
+=item B<clone_instance($instance, %params)>
+
+This method is a compliment of C<construct_instance> (which means if
+you override C<construct_instance>, you need to override this one too).
+
+This method will clone the C<$instance> structure created by the
+C<construct_instance> method, and apply any C<%params> passed to it
+to change the attribute values. The structure returned is (like with
+C<construct_instance>) an unC<bless>ed HASH reference, it is your
+responsibility to then bless this cloned structure into the right
+class.
+
=back
=head2 Informational
=item B<compute_all_applicable_attributes>
-This will traverse the inheritance heirachy and return a list of HASH
-references for all the applicable attributes for this class. The HASH
-references will contain the following information; the attribute name,
-the class which the attribute is associated with and the actual
-attribute meta-object.
+This will traverse the inheritance heirachy and return a list of all
+the applicable attributes for this class. It does not construct a
+HASH reference like C<compute_all_applicable_methods> because all
+that same information is discoverable through the attribute
+meta-object itself.
=back