How do I get a PHP class constructor to call its parent's parent's constructor?

Question

I need to have a class constructor in PHP call its parent\'s parent\'s (grandparent?) constructor without calling the parent constructor.

//         


        

Answer 1

There's an easier solution for this, but it requires that you know exactly how much inheritance your current class has gone through. Fortunately, get_parent_class()'s arguments allow your class array member to be the class name as a string as well as an instance itself.

Bear in mind that this also inherently relies on calling a class' __construct() method statically, though within the instanced scope of an inheriting object the difference in this particular case is negligible (ah, PHP).

Consider the following:

class Foo {
    var $f = 'bad (Foo)';

    function __construct() {
        $this->f = 'Good!';
    }
}

class Bar extends Foo {
    var $f = 'bad (Bar)';
}

class FooBar extends Bar {
    var $f = 'bad (FooBar)';

    function __construct() {
        # FooBar constructor logic here
        call_user_func(array(get_parent_class(get_parent_class($this)), '__construct'));
    }
}

$foo = new FooBar();
echo $foo->f; #=> 'Good!'

Again, this isn't a viable solution for a situation where you have no idea how much inheritance has taken place, due to the limitations of debug_backtrace(), but in controlled circumstances, it works as intended.