use warnings;
use Carp 'confess';
-use Scalar::Util 'blessed', 'reftype';
+use Scalar::Util 'blessed', 'reftype', 'weaken';
-our $VERSION = '0.01';
+our $VERSION = '0.08';
sub meta {
require Class::MOP::Class;
- Class::MOP::Class->initialize($_[0])
+ Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
}
# NOTE: (meta-circularity)
(defined $name && $name)
|| confess "You must provide a name for the attribute";
- (!exists $options{reader} && !exists $options{writer})
- || confess "You cannot declare an accessor and reader and/or writer functions"
- if exists $options{accessor};
+ $options{init_arg} = $name
+ if not exists $options{init_arg};
bless {
name => $name,
writer => $options{writer},
predicate => $options{predicate},
init_arg => $options{init_arg},
- default => $options{default}
+ default => $options{default},
+ # keep a weakened link to the
+ # class we are associated with
+ associated_class => undef,
} => $class;
}
+# NOTE:
+# this is a primative (and kludgy) clone operation
+# for now, it will be repleace in the Class::MOP
+# bootstrap with a proper one, however we know
+# that this one will work fine for now.
+sub clone {
+ my $self = shift;
+ my %options = @_;
+ (blessed($self))
+ || confess "Can only clone an instance";
+ return bless { %{$self}, %options } => blessed($self);
+}
+
+sub initialize_instance_slot {
+ my ($self, $instance, $params) = @_;
+ my $init_arg = $self->{init_arg};
+ # 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)
+ if (!defined $val && defined $self->{default}) {
+ $val = $self->default($instance);
+ }
+
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ $meta_instance->set_slot_value_with_init( $instance, $self->slot_name, $val );
+}
+
+# NOTE:
+# the next bunch of methods will get bootstrapped
+# away in the Class::MOP bootstrapping section
+
sub name { $_[0]->{name} }
+sub associated_class { $_[0]->{associated_class} }
+
sub has_accessor { defined($_[0]->{accessor}) ? 1 : 0 }
sub has_reader { defined($_[0]->{reader}) ? 1 : 0 }
sub has_writer { defined($_[0]->{writer}) ? 1 : 0 }
sub predicate { $_[0]->{predicate} }
sub init_arg { $_[0]->{init_arg} }
+# end bootstrapped away method section.
+# (all methods below here are kept intact)
+
sub default {
my $self = shift;
if (reftype($self->{default}) && reftype($self->{default}) eq 'CODE') {
$self->{default};
}
-{
- # this is just a utility routine to
- # handle the details of accessors
- my $_inspect_accessor = sub {
- my ($attr_name, $type, $accessor) = @_;
-
- my %ACCESSOR_TEMPLATES = (
- 'accessor' => qq{sub {
- \$_[0]->{'$attr_name'} = \$_[1] if scalar(\@_) == 2;
- \$_[0]->{'$attr_name'};
- }},
- 'reader' => qq{sub {
- \$_[0]->{'$attr_name'};
- }},
- 'writer' => qq{sub {
- \$_[0]->{'$attr_name'} = \$_[1];
- }},
- 'predicate' => qq{sub {
- defined \$_[0]->{'$attr_name'} ? 1 : 0;
- }}
- );
-
- if (reftype($accessor) && reftype($accessor) eq 'HASH') {
- my ($name, $method) = each %{$accessor};
- return ($name, Class::MOP::Attribute::Accessor->wrap($method));
- }
- else {
- my $method = eval $ACCESSOR_TEMPLATES{$type};
- confess "Could not create the $type for $attr_name CODE(\n" . $ACCESSOR_TEMPLATES{$type} . "\n) : $@" if $@;
- return ($accessor => Class::MOP::Attribute::Accessor->wrap($method));
- }
+# class association
+
+sub attach_to_class {
+ my ($self, $class) = @_;
+ (blessed($class) && $class->isa('Class::MOP::Class'))
+ || confess "You must pass a Class::MOP::Class instance (or a subclass)";
+ weaken($self->{associated_class} = $class);
+}
+
+sub detach_from_class {
+ my $self = shift;
+ $self->{associated_class} = undef;
+}
+
+# slot management
+
+sub slot_name { # when attr <-> slot mapping is 1:1
+ my $self = shift;
+ $self->name;
+}
+
+# slot alocation
+
+sub allocate_slots {
+ my $self = shift;
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ $meta_instance->add_slot( $self->slot_name );
+}
+
+sub deallocate_slots {
+ my $self = shift;
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ $meta_instance->remove_slot( $self->slot_name );
+}
+
+## Method generation helpers
+
+sub generate_accessor_method {
+ my $self = shift;
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ my $slot_name = $self->slot_name;
+
+ sub {
+ $meta_instance->set_slot_value($_[0], $slot_name, $_[1]) if scalar(@_) == 2;
+ $meta_instance->get_slot_value($_[0], $slot_name);
};
+}
- sub install_accessors {
- my ($self, $class) = @_;
- (blessed($class) && $class->isa('Class::MOP::Class'))
- || confess "You must pass a Class::MOP::Class instance (or a subclass)";
- $class->add_method(
- $_inspect_accessor->($self->name, 'accessor' => $self->accessor())
- ) if $self->has_accessor();
-
- $class->add_method(
- $_inspect_accessor->($self->name, 'reader' => $self->reader())
- ) if $self->has_reader();
-
- $class->add_method(
- $_inspect_accessor->($self->name, 'writer' => $self->writer())
- ) if $self->has_writer();
-
- $class->add_method(
- $_inspect_accessor->($self->name, 'predicate' => $self->predicate())
- ) if $self->has_predicate();
- return;
+sub generate_reader_method {
+ my $self = shift;
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ my $slot_name = $self->slot_name;
+ sub {
+ confess "Cannot assign a value to a read-only accessor" if @_ > 1;
+ $meta_instance->get_slot_value($_[0], $slot_name);
+ };
+}
+
+sub generate_writer_method {
+ my $self = shift;
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ my $slot_name = $self->slot_name;
+ sub {
+ $meta_instance->set_slot_value($_[0], $slot_name, $_[1]);
+ };
+}
+
+sub generate_predicate_method {
+ my $self = shift;
+ my $meta_instance = $self->associated_class->get_meta_instance;
+ my $slot_name = $self->slot_name;
+ sub {
+ defined $meta_instance->get_slot_value($_[0], $slot_name);
+ };
+}
+
+sub process_accessors {
+ my ($self, $type, $accessor) = @_;
+ if (reftype($accessor)) {
+ (reftype($accessor) eq 'HASH')
+ || confess "bad accessor/reader/writer/predicate format, must be a HASH ref";
+ my ($name, $method) = each %{$accessor};
+ return ($name, Class::MOP::Attribute::Accessor->wrap($method));
}
+ else {
+ my $generator = $self->can('generate_' . $type . '_method');
+ ($generator)
+ || confess "There is no method generator for the type='$type'";
+ if (my $method = $self->$generator($self->name)) {
+ return ($accessor => Class::MOP::Attribute::Accessor->wrap($method));
+ }
+ confess "Could not create the '$type' method for " . $self->name . " because : $@";
+ }
+}
+
+sub install_accessors {
+ my $self = shift;
+ my $class = $self->associated_class;
+ $class->add_method(
+ $self->process_accessors('accessor' => $self->accessor())
+ ) if $self->has_accessor();
+
+ $class->add_method(
+ $self->process_accessors('reader' => $self->reader())
+ ) if $self->has_reader();
+
+ $class->add_method(
+ $self->process_accessors('writer' => $self->writer())
+ ) if $self->has_writer();
+
+ $class->add_method(
+ $self->process_accessors('predicate' => $self->predicate())
+ ) if $self->has_predicate();
+ return;
}
{
};
sub remove_accessors {
- my ($self, $class) = @_;
- (blessed($class) && $class->isa('Class::MOP::Class'))
- || confess "You must pass a Class::MOP::Class instance (or a subclass)";
- $_remove_accessor->($self->accessor(), $class) if $self->has_accessor();
- $_remove_accessor->($self->reader(), $class) if $self->has_reader();
- $_remove_accessor->($self->writer(), $class) if $self->has_writer();
- $_remove_accessor->($self->predicate(), $class) if $self->has_predicate();
+ my $self = shift;
+ $_remove_accessor->($self->accessor(), $self->associated_class()) if $self->has_accessor();
+ $_remove_accessor->($self->reader(), $self->associated_class()) if $self->has_reader();
+ $_remove_accessor->($self->writer(), $self->associated_class()) if $self->has_writer();
+ $_remove_accessor->($self->predicate(), $self->associated_class()) if $self->has_predicate();
return;
}
MyClass->meta->construct_instance(-foo => "Hello There");
+In an init_arg is not assigned, it will automatically use the
+value of C<$name>.
+
=item I<default>
The value of this key is the default value which
=back
+=item B<clone (%options)>
+
+=item B<initialize_instance_slot ($instance, $params)>
+
=back
=head2 Informational
=back
+=head2 Class association
+
+=over 4
+
+=item B<associated_class>
+
+=item B<attach_to_class ($class)>
+
+=item B<detach_from_class>
+
+=item B<slot_name>
+
+=item B<allocate_slots>
+
+=item B<deallocate_slots>
+
+=back
+
=head2 Attribute Accessor generation
=over 4
-=item B<install_accessors ($class)>
+=item B<install_accessors>
This allows the attribute to generate and install code for it's own
I<accessor/reader/writer/predicate> methods. This is called by
C<Class::MOP::Class::add_attribute>.
-=item B<remove_accessors ($class)>
+This method will call C<process_accessors> for each of the possible
+method types (accessor, reader, writer & predicate).
+
+=item B<process_accessors ($type, $value)>
+
+This takes a C<$type> (accessor, reader, writer or predicate), and
+a C<$value> (the value passed into the constructor for each of the
+different types). It will then either generate the method itself
+(using the C<generate_*_method> methods listed below) or it will
+use the custom method passed through the constructor.
+
+=over 4
+
+=item B<generate_accessor_method>
+
+=item B<generate_predicate_method>
+
+=item B<generate_reader_method>
+
+=item B<generate_writer_method>
+
+=back
+
+=item B<remove_accessors>
This allows the attribute to remove the method for it's own
I<accessor/reader/writer/predicate>. This is called by
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
-=cut
+=cut
\ No newline at end of file