Single inheritance has often been the limitation for PHP. This means that a class can only inherit from one other class. Often classes share the same methods and it would be beneficial to allow reuse and prevent duplication.

In PHP 5.4 a new feature was added, known as Traits. A Trait is like a Mixin, allowing to use / mix classes into existing classes. This means code reduction and less duplication.

Example of a Trait

trait Sharable {
 
  public function share($item)
  {
    return 'share this item';
  }
 
}

trait Sharable {

public function share($item)

{

return 'share this item';

}

This trait can than be used in other classes:

class Post {
 
  use Sharable;
 
}
 
class Comment {
 
  use Sharable;
 
}

class Post {

use Sharable;

}

class Comment {

use Sharable;

}

Both classes can now use the Shareable trait.

$post = new Post;
echo $post->share(''); // 'share this item' 
 
$comment = new Comment;
echo $comment->share(''); // 'share this item'

$post = new Post;

echo $post->share(''); // 'share this item'

$comment = new Comment;

echo $comment->share(''); // 'share this item'

The benefit is less code duplication. The drawback is, that not all used methods are visible within the source-code of the class. So before moving a method to a trait, make sure that you will actually reuse it ;)

I have been restructuring huge amounts of code over the past months and traits are helping to keep things far more organized.

In combination with __autoload its a real nice way to cleanup your code toolbox.

Happy coding
Alex

Clean up your toolbox with PHP traits …

Alexander