Can PHP do a fairly trivial inheritance thing?

Question

I have the following code:

abstract class AbstractParent {
 function __construct($param) { print_r($param); }
 public static function test() { return new self(1234); }
}

class SpecificClass extends AbstractParent {}

When I invoke SpecificClass::test(), I am getting an error:

Fatal error: Cannot instantiate abstract class AbstractParent

So what I basically want is just to let AbstractParent's test() instantiate class where this test() was called from (so, in my example, instantiate SpecificClass).

I've been seeing people complain a lot about late static binding lately and I'm curious: What other languages commonly used for web development *do* support late static binding? Python? Ruby? Perl? Java? — Ariel Arjona, Dec 15 '08 at 02:39
all of them, afair. I used Ruby extensively over past couple of years. — Yurii Rashkovskii, Dec 15 '08 at 02:46
possible duplicate of [Inheritance of static members in PHP](http://stackoverflow.com/questions/532754/inheritance-of-static-members-in-php) — hakre, Jul 01 '12 at 15:43

score 4 · Answer 1 · answered Dec 15 '08 at 02:37

4

Prior version 5.3 Only with the following work around:

abstract class AbstractParent {
 function __construct($param) { print_r($param); }
 abstract public static function test();
 private static function test2($classname) { return new $classname(1234); }
}

class SpecificClass extends AbstractParent {
 public static function test() {return self::test2(__CLASS__);}
}

answered Dec 15 '08 at 02:37

Alexei Tenitski

9,030
6
41
50

2

You don't have to have the two static methods named differently. You can call them "test" in both classes and have SpecificClass::test return parent::test. – grantwparks Oct 22 '09 at 00:46

score 3 · Answer 2 · answered Dec 15 '08 at 02:29

You can do it in PHP 5.3, which is still in alpha. What you're looking for is called Late-Static-Binding. You want the parent class to refer to the child class in a static method. You can't do it yet, but it's coming...

Edit: You can find more info here - http://www.php.net/manual/en/language.oop5.late-static-bindings.php

Can PHP do a fairly trivial inheritance thing?

2 Answers2