more-method-refactoring

[gitmo/Class-MOP.git] / examples / LazyClass.pod

diff --git a/examples/LazyClass.pod b/examples/LazyClass.pod
index 8aaa30c..7c9d00a 100644 (file)
--- a/examples/LazyClass.pod
+++ b/examples/LazyClass.pod
@@ -1,68 +1,94 @@
 
 package # hide the package from PAUSE
-    LazyClass;
+    LazyClass::Attribute;
 
 use strict;
 use warnings;
 
-our $VERSION = '0.02';
-
-use base 'Class::MOP::Class';
-
-sub construct_instance {
-    my ($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
-        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};
-        # now add this to the instance structure
-        # only if we have found a value at all
-        $instance->{$attr->name} = $val if defined $val;
-    }
-    return $instance;    
+use Carp 'confess';
+
+our $VERSION = '0.05';
+
+use base 'Class::MOP::Attribute';
+
+sub initialize_instance_slot {
+    my ($self, $meta_instance, $instance, $params) = @_;
+
+    # if the attr has an init_arg, use that, otherwise,
+    # use the attributes name itself as the init_arg
+    my $init_arg = $self->init_arg();
+
+       if ( exists $params->{$init_arg} ) {
+               my $val = $params->{$init_arg};
+               $meta_instance->set_slot_value($instance, $self->name, $val);
+       }
 }
 
+sub accessor_metaclass { 'LazyClass::Method::Accessor' }
+
 package # hide the package from PAUSE
-    LazyClass::Attribute;
+    LazyClass::Method::Accessor;
 
 use strict;
 use warnings;
 
-our $VERSION = '0.02';
+use Carp 'confess';
 
-use base 'Class::MOP::Attribute';
+our $VERSION = '0.01';
+
+use base 'Class::MOP::Method::Accessor';
 
 sub generate_accessor_method {
-    my ($self, $attr_name) = @_;
+    my $attr = (shift)->associated_attribute;
+
+       my $attr_name = $attr->name;
+       my $meta_instance = $attr->associated_class->get_meta_instance;
+
     sub {
         if (scalar(@_) == 2) {
-            $_[0]->{$attr_name} = $_[1];
+                       $meta_instance->set_slot_value($_[0], $attr_name, $_[1]);
         }
         else {
-            if (!exists $_[0]->{$attr_name}) {
-                my $attr = $self->associated_class->get_attribute($attr_name);
-                $_[0]->{$attr_name} = $attr->has_default ? $attr->default($_[0]) : undef;           
-            }            
-            $_[0]->{$attr_name};            
+                       unless ( $meta_instance->is_slot_initialized($_[0], $attr_name) ) {
+                               my $value = $attr->has_default ? $attr->default($_[0]) : undef;
+                               $meta_instance->set_slot_value($_[0], $attr_name, $value);
+            }
+
+            $meta_instance->get_slot_value($_[0], $attr_name);
         }
     };
 }
 
 sub generate_reader_method {
-    my ($self, $attr_name) = @_; 
+    my $attr = (shift)->associated_attribute;
+
+       my $attr_name = $attr->name;
+       my $meta_instance = $attr->associated_class->get_meta_instance;
+
     sub {
-        if (!exists $_[0]->{$attr_name}) {
-            my $attr = $self->associated_class->get_attribute($attr_name);
-            $_[0]->{$attr_name} = $attr->has_default ? $attr->default($_[0]) : undef;           
-        }
-        $_[0]->{$attr_name};
+        confess "Cannot assign a value to a read-only accessor" if @_ > 1;        
+
+               unless ( $meta_instance->is_slot_initialized($_[0], $attr_name) ) {
+                       my $value = $attr->has_default ? $attr->default($_[0]) : undef;
+                       $meta_instance->set_slot_value($_[0], $attr_name, $value);
+               }
+
+               $meta_instance->get_slot_value($_[0], $attr_name);
     };   
 }
 
+package # hide the package from PAUSE
+    LazyClass::Instance;
+
+use strict;
+use warnings;
+
+our $VERSION = '0.01';
+
+use base 'Class::MOP::Instance';
+
+sub initialize_all_slots {}
+
 1;
 
 __END__
@@ -77,8 +103,9 @@ LazyClass - An example metaclass with lazy initialization
 
   package BinaryTree;
   
-  use metaclass 'LazyClass' => (
-      ':attribute_metaclass' => 'LazyClass::Attribute'
+  use metaclass (
+      ':attribute_metaclass' => 'LazyClass::Attribute',
+      ':instance_metaclass'  => 'LazyClass::Instance',      
   );
   
   BinaryTree->meta->add_attribute('$:node' => (
@@ -96,9 +123,9 @@ LazyClass - An example metaclass with lazy initialization
       default => sub { BinaryTree->new() }    
   ));    
   
-  sub new {
+  sub new  {
       my $class = shift;
-      bless $class->meta->construct_instance(@_) => $class;
+      $class->meta->new_object(@_);
   }
   
   # ... later in code
@@ -118,10 +145,12 @@ without complicating the programing of it. This would also be
 ideal for a class which has a large amount of attributes, 
 several of which are optional. 
 
-=head1 AUTHOR
+=head1 AUTHORS
 
 Stevan Little E<lt>stevan@iinteractive.comE<gt>
 
+Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
+
 =head1 COPYRIGHT AND LICENSE
 
 Copyright 2006 by Infinity Interactive, Inc.
@@ -131,4 +160,4 @@ 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
\ No newline at end of file
+=cut