++ed by:
ABRAXXA ADAMJS ALEXBIO ALEXBYK ANDREFS

121 PAUSE user(s)
88 non-PAUSE user(s).

Jesse Luehrs

NAME

ClassEncapsulatedAttributes - A set of example metaclasses with class encapsulated attributes

SYNOPSIS

  package Foo;
  
  use metaclass 'ClassEncapsulatedAttributes';
  
  Foo->meta->add_attribute('foo' => (
      accessor  => 'Foo_foo',
      default   => 'init in FOO'
  ));
  
  sub new  {
      my $class = shift;
      $class->meta->new_object(@_);
  }
  
  package Bar;
  our @ISA = ('Foo');
  
  # duplicate the attribute name here
  Bar->meta->add_attribute('foo' => (
      accessor  => 'Bar_foo',
      default   => 'init in BAR'            
  ));      
  
  # ... later in other code ...
  
  my $bar = Bar->new();
  prints $bar->Bar_foo(); # init in BAR
  prints $bar->Foo_foo(); # init in FOO  
  
  # and ...
  
  my $bar = Bar->new(
      'Foo' => { 'foo' => 'Foo::foo' },
      'Bar' => { 'foo' => 'Bar::foo' }        
  );  
  
  prints $bar->Bar_foo(); # Foo::foo
  prints $bar->Foo_foo(); # Bar::foo  
  

DESCRIPTION

This is an example metaclass which encapsulates a class's attributes on a per-class basis. This means that there is no possibility of name clashes with inherited attributes. This is similar to how C++ handles its data members.

ACKNOWLEDGEMENTS

Thanks to Yuval "nothingmuch" Kogman for the idea for this example.

AUTHORS

Stevan Little <stevan@iinteractive.com>

Yuval Kogman <nothingmuch@woobling.com>

COPYRIGHT AND LICENSE

Copyright 2006-2008 by Infinity Interactive, Inc.

http://www.iinteractive.com

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.




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