Faking Late Static Binding before php 5.3

Question

I need an inherited static function \"call\" to call another static function \"inner\" that has been overridden. I could do this with late static binding, but my host does

Answer 1

Often, late static binding is needed when a child calls back a method of the parent who, in turn, calls an abstract static method of the child. I was in such a postition, and could not use static:: as my PHP was not version 5.3 (or later). The following accomplished late static binding by way of debug_backtrace().

abstract class ParentClass
{
    static function parent_method()
    {
        $child_class_str = self::get_child_class();
        eval("\$r = ".$child_class_str."::abstract_static();");
        return $r;
    }// CHILD MUST OVERRIDE TO PUT ITSELF INTO TRACE

    protected abstract static function abstract_static(); // THIS NEEDS LATE STATIC BINDING

    private static function get_child_class()
    {
        $backtrace = debug_backtrace();
        $num = count($backtrace);
        for($i = 0; $i < $num; $i++)
        {
             if($backtrace[$i]["class"] !== __CLASS__)
                  return $backtrace[$i]["class"];
        }
        return null;
    }
}

class ChildClass extends ParentClass
{
    static function parent_method(){ return parent::parent_method(); }

    protected static function abstract_static()
    {
        return __METHOD__."()";
    }// From ParentClass
}

print "The call was: ". ChildClass::parent_method();