Mastering PHP Design Patterns

Bridge

The Bridge pattern can be quite straightforward; it effectively allows us to decouple an abstraction from an implementation so the two can vary independently.

When classes vary frequently, bridging an interface and a concrete class allows developers to vary their classes with greater ease.

Let's propose a generic messenger interface that has the ability to send some form of message, Messenger.php:

<?php 
 
interface Messenger 
{ 
  public function send($body); 
} 

One specific implementation of this interface is an InstantMessenger application, InstantMessenger.php:

<?php 
 
class InstantMessenger implements Messenger 
{ 
  public function send($body) 
  { 
    echo "InstantMessenger: " . $body; 
  } 
} 

Similarly, we can do the same with an SMS application, SMS.php: