Question

Below is an example of what I’m trying to do. The parent can’t access any of the child’s variables. It doesn’t matter what technique I use (static or constants), I just need some kind of functionality like this.

class ParentClass
{
    public static function staticFunc()
    {
        //both of these will throw a (static|const) not defined error
        echo self::$myStatic;
        echo self::MY_CONSTANT;
    }
}

class ChildClass extends ParentClass
{
    const MY_CONSTANT = 1;
    public static $myStatic = 2;
}

ChildClass::staticFunc();

I know this sucks, but I am not using 5.3. Any hacky solution that involves eval is more than welcome.

Answer 1

EDIT: The < 5.3 requirement was added after the response was written. In this case, a hacky solution exists with debug_backtrace. Have fun.

And, just to be sure… I suppose echo ParentClass::$myStatic; is out of question. Again, I struggle to find a use case for this. It’s certainly esoteric to find such a static method that would only be called using another class. It’s a kind of bastardized abstract method.

ORIGINAL:

Yes, with late static bindings:

<?php
class ParentClass
{
    public static function staticFunc()
    {
        echo static::$myStatic;
        echo static::MY_CONSTANT;
    }
}

class ChildClass extends ParentClass
{
    const MY_CONSTANT = 1;
    public static $myStatic = 2;
}

ChildClass::staticFunc(); //21
/* the next statement gives fatal error: Access to undeclared static
 * property: ParentClass::$myStatic */
ParentClass::staticFunc();

I would say it’s not a great design though. It would make more sense if ParentClass also defined the static property and the constant.

This feature was introduced in PHP 5.3.