creating_php_classes_with_composer.md

Creating the Sample classes

If you are currently reading the Mouf Dependency Injection guide and if you are new to using Composer and are not very familiar with things like PSR-0 and PSR-4 autoloading schemes, this chapter might help you a bit.

We are using Composer, and therefore, we can use the Composer autoloading system. The best thing to do is to declare our classes using the PSR-0 notation. This is a PHP 5.3 thing (mostly), so we will also declare a namespace for the classes. Let's put all our classes in the Mouf\Sample namespace.

Let's also say all the classes go into the src folder.

The first thing to do is to declare the namespace in composer.json:

{
    "require": {
        "mouf/mouf": "~2.0"
    },
    "autoload": {
        "psr-0": {
            "Mouf\\Sample": "src/"
        }
    }
}

Have a look at the autoload section. We are declaring that the Mouf\Sample namespace will be in the src/ directory. This means that Mouf will be able to find any class in the src\Mouf\Sample directory, as long as they are respecting the PSR-0 naming scheme.

Note: each time you change the "autoload" section of composer, you MUST run one of these 2 commands to update the autoloader:

php composer.phar dumpautoload

or

`php composer.phar install

In our particular case, there will be 3 classes and 1 interface:

src/Mouf/Sample/Warrior.php

namespace Mouf\Sample;

class Warrior {
	private $leftHandWeapon;
	private $rightHandWeapon;
	private $hp;
	
	/**
	 * @param WeaponInterface $leftHandWeapon
	 * @param WeaponInterface $rightHandWeapon
	 * @param int $hp
	 */
	public function __construct(WeaponInterface $leftHandWeapon, 
			WeaponInterface $rightHandWeapon,
			$hp) {
		$this->leftHandWeapon = $leftHandWeapon;
		$this->rightHandWeapon = $rightHandWeapon;
		$this->hp = $hp;
	}
	
	public function attack(Warrior $warrior) {
		$this->leftHandWeapon->attack($warrior);
		$this->rightHandWeapon->attack($warrior);
	}
	
	public function removeHp($hp) {
		$this->hp -= $hp;
		if ($this->hp <= 0) {
			echo "I'm dead!";
		}
	}
}

src/Mouf/Sample/WeaponInterface.php

namespace Mouf\Sample;

interface WeaponInterface {
	function attack(Warrior $warrior);
}

src/Mouf/Sample/Axe.php

namespace Mouf\Sample;

class Axe implements WeaponInterface {
	const DAMAGE = 7;
	
	public function attack(Warrior $warrior) {
		$warrior->removeHp(self::DAMAGE);
	}
}

src/Mouf/Sample/Sword.php

namespace Mouf\Sample;

class Sword implements WeaponInterface {
	const DAMAGE = 5;
	
	public function attack(Warrior $warrior) {
		$warrior->removeHp(self::DAMAGE);
	}
}

Ok, was it easy enough? Let's get back to the Dependency Injection with Mouf documentation