Question

Is it possible to block the visibility of functions from a parent class in sub classes?

class DB {
  function connect() {
    // connects to db
  }
}
class OtherClass extends DB {
  function readData() {
    // reads data
  }
}
class AnotherOtherClass extends OtherClass {
  function updateUser($username) {
    // add username
  }
}

If I were to write:

$cls1= new OtherClass();
$cls1->connect(); // want to allow this class to show

$cls2= new AnotherOtherClass();
$cls2->connect(); // do not want this class to show
$cls2->readData(); // want to allow this class to show

Is this possible?

Answer 1

Sounds like you don’t actually want AnotherOtherClass to extend OtherClass. Perhaps you want to consume / wrap / decorate OtherClass instead, eg

class AnotherOtherClass
{
    private $other;

    public function __construct(OtherClass $other)
    {
        $this->other = $other;
    }

    public function readData()
    {
        // proxy to OtherClass::readData()
        return $this->other->readData();
    }

    public function updateUser($username)
    {
        // add username
    }
}

You could also do this but it smells bad

class AnotherOtherClass extends OtherClass
{
    public function connect()
    {
        throw new BadMethodCallException('Not available in ' . __CLASS__);
    }