An experiment to implement the Javascript Prototype principle in PHP 5.3

jPrototype.php

<?php
    class jPrototype {
        protected static $prototype = array();
        public static function prototype() {
            if ( !self::$prototype ) {
                self::$prototype = new self();
            }
            return self::$prototype;
        }
        public function __set($property, $value) {
            $this->$property = $value;
        }
        public function __get($property) {
            if ( $property === 'prototype') {
                return self::prototype(); 
            }
            if ( isset($this->$property) ) {
                return $this->$property;
            } else {
                return isset( self::$prototype->$property ) ?
                    self::$prototype->$property : null;
            }
        }
        public function __call($func, $args) {
            if ( !($fn = $this->__get($func)) ) {
                throw new BadMethodCallException(
                    'Undefined function ' . get_class($this) . '::' . $func
                );
            }
            return call_user_func_array(
                $fn,
                $args
            );
        }
    }
    
    /**
     * The initial class
     */
    class Foo extends jPrototype {
    }
    
    Foo::prototype()->hello = function() {
        return 'Hello Foo Initial'. "\n";
    };
    
    // using the prototype declaration
    $obj = new Foo();
    echo $obj->hello();
    
    // update the declaration
    Foo::prototype()->hello = function() {
        return 'Hello Foo Updated'. "\n";
    };
    echo $obj->hello();

    // creating a new class
    $bar = new Foo();
    $bar->hello = function() {
        return 'Hello from bar (only)' ."\n";
    };
    echo $bar->hello();
    
    // test that not changed the foo prototype
    echo $obj->hello();
    
    // updating the prototype from an instance
    $bar->prototype->hello = function() {
        return 'I was globally changed from $bar !'."\n";
    };
    echo $obj->hello();