Question

I am a little confused with this matter. I am designing an ORM class that tries to behave very similarly to ActiveRecord in ruby on rails, but that’s beside the point.

What I’m trying to say is that my class makes extensive use of static attribute inheritance, specially for database and table handling. My question is, should I use self:: at all?

Answer 1

You have to ask yourself: “Am I targeting the problem with the adequated approach?”

self:: and static:: do two different things. For instance self:: or __CLASS__ are references to the current class, so defined in certain scope it will NOT suffice the need of static calling on forward.

What will happen on inheritance?

class A {
    public static function className(){
        echo __CLASS__;
    }

    public static function test(){
        self::className();
    }
}

class B extends A{
    public static function className(){
        echo __CLASS__;
    }
}

B::test();

This will print

A

In the other hand with static:: It has the expected behaviour

class A {
    public static function className(){
        echo __CLASS__;
    }

    public static function test(){
        static::className();
    }
}

class B extends A{
    public static function className(){
        echo __CLASS__;
    }
}


B::test();

This will print

B

That is called late static binding in PHP 5.3.0. It solves the limitation of calling the class that was referenced at runtime.

With that in mind I think you can now see and solve the problem adequately. If you are inheriting several static members and need access to the parent and child members self:: will not suffice.