Implementing the Adapter Pattern in PHP | CodeSignal Learn

Implementing the Adapter Pattern in PHP | CodeSignal Learn

In this lesson, you'll learn how to implement the Adapter Pattern in PHP. We'll begin with a straightforward example where a European plug is connected to a U.S. socket.

The following snippet defines a EuropeanPlug class with an engage method:

PHP

<?php

class EuropeanPlug {
    public function engage() {
        echo "European plug connected.";
    }
}

Next, we have a USPlug interface, which specifies the connect method required by the client:

PHP

interface USPlug {
    public function connect();
}

Finally, here's an Adapter class that adapts the EuropeanPlug to the USPlug interface:

PHP

class Adapter implements USPlug {
    private $plug;

    public function __construct(EuropeanPlug $plug) {
        $this->plug = $plug;
    }

    public function connect() {
        $this->plug->engage();
    }
}

Here's how to interact with these classes:

$europeanPlug = new EuropeanPlug();
$adapter = new Adapter($europeanPlug);

$adapter->connect(); // Output: European plug connected.

In this example, the EuropeanPlug contains a method engage that we wish to adapt to fit the USPlug interface. The Adapter class serves as the bridge between these two interfaces by implementing the USPlug interface and delegating calls to the EuropeanPlug object.