PHP OOP继承问题

Question

I have an inheritance issue. Consider I have a parent class A and a derived class B from A and a derived Class C from A again.

Let's say, class B & C both override method seed() from class A. Also clases A & B & C all implement a static function seedAll().

My question is: How do I call seedAll for B & C from the seedAll function of A without explicitly specifying the class B & C, so that in the future, should I have a class D similar to class B & C, I need not modify the seedAll function of class A to call the seedAll functions of classes B, C & D.

abstract class A
{
    public static function seedAll() {
        //How do I call seedAll of all the derived classes of Seeder?
    }

    abstract protected function seed();
    // // Common method
    // public function printOut() {
    //     print $this->getValue() . "
";
    // }
}

class B extends A
{
    private $name;

    function __construct($name) {
        $this->name = $name;
    }

    public static function seedAll() {
        $seeder1 = new B("name1");
        $seeder1 = new B("name2");
    }

    function seed() {
        echo $this->name;
    }
}


  class C extends A
    {
        private $name;

        function __construct($name) {
            $this->name = $name;
        }

        public static function seedAll() {
            $seeder1 = new C("name1");
            $seeder1 = new C("name2");
        }

        function seed() {
            echo $this->name;
        }
    }

Answer 1

See how to obtain all subclasses of a class in php for how to get all the subclasses. You can then loop over them and call their seedAll() methods.

abstract class A
{
    public static function seedAll() {
        $subclasses = getSubclassesOf("A");
        foreach ($subclasses as $class) {
            $class::seedAll();
        }
    }

    abstract protected function seed();
    // // Common method
    // public function printOut() {
    //     print $this->getValue() . "
";
    // }
}

getSubclassesOf function:

function getSubclassesOf($parent) {
    $result = array();
    foreach (get_declared_classes() as $class) {
        if (is_subclass_of($class, $parent))
            $result[] = $class;
    }
    return $result;
}