PHP design patterns (Creational : part 2)

Let’s continue in our exploration of PHP data structures.

In the first episode, we talked about the “simple factory” pattern.

Now, we’ll go into a slightly more advanced structure.

Let’s talk about the Factory method:

The point of this pattern , can be compressed into one word : delegation.

Let’s imagine that just got an access to play to your favorite heroic fantasy video game.

Imagine there are 2 classes of characters to chose from :

• Warriors
• Druids

You decided to share the access of your account to two of your friends.

One of your friends like to play Warriors , while the other one likes to play Druids.

Here the character classes :

interface Character {
public function attack();
}
class Warrior implements Character {
public function attack(){
echo 'the warrior attacks';
}
}
class Druid implements Character {
        
    public function attack(){
        echo 'the Druid attacks';
  }
}

Let’s use an abstract class , representing the idea of delegation.

abstract class player{
    abstract protected function createCharacter(): Character;
      public function attack(){
         $character = $this->createCharacter();
         $character->attack();
      }
}
class friendA extends player{
   protected function createCharacter(){
        return new Warrior();
     }
}
class friendB extends player{
     protected function createCharacter(){
         return new Thief();
      }
}

Now, you have 2 different friends, allowed to perform actions as a player. But even though they structurally use similar functions, they implement these functions in different fashions. They actually build distinct characters.

$friendA = new FriendA();
$friendA->attack(); //Output : the warrior attacks
$friendB = new FriendB();
$friendB->attack(); //Output : the Druid attacks