php-src/ext/overload

The purpose of this extension is to allow user-space overloading of object
property access and method calls. It has only one function, overload() which
takes the name of the class that should have this functionality enabled. But
the class has to define appropriate methods if it wants to have this
functionality: __get(), __set(), and __call(). So, overloading can be
selective.

Inside each handler the overloading is disabled so you can access object
properties normally.


Usage
-----
<?php

class OO {
    var $a = 111;
    var $elem = array('b' => 9, 'c' => 42);

    function OO($aval = null)
    {
        $this->a = $aval;
    }

    function __get($prop_name, &$prop_value)
    {
        if (isset($this->elem[$prop_name])) {
            $prop_value = $this->elem[$prop_name];
            return true;
        } else
           return false;
    }

    function __set($prop_name, $prop_value)
    {
        $this->elem[$prop_name] = $prop_value;
        return true;
    }

    function __call($method, $args, &$return_value)
    {
        print '-- OO::' . $method . "() was called.--\n";
        $return_value = call_user_func_array(array(&$this, 'my_' . $method), $args);
        return true;
    }

    function my_whatever($f1, $f2, $f3)
    {
        var_dump($f1, $f2, $f3);
        return $f1 + $f2;
    }

    function __get_foo(&$prop_value)
    {
        $prop_value = 'Bam bam bam!';
        return true;
    }

    function __set_count($prop_value)
    {
        if ($prop_value >= 1 && $prop_value <= 100) {
			$this->elem['COUNT'] = $prop_value;
			return true;
        } else
            return false;
    }
}

overload('OO');

$o = new OO;
print "\$o->a: $o->a\n";
print "\$o->b: $o->b\n";
print "\$o->c: $o->c\n";
print "\$o->d: $o->d\n";

$val = new stdclass;
$val->prop = 555;

$o->a = array($val);
var_dump($o->a[0]->prop);

var_dump($o->whatever(1, 2, 'a'));

var_dump($o->foo);
$o->count = 100;
var_dump($o->COUNT);

?>

What doesn't work
-----------------
Invoking original overloading handlers, if the class had any.
__set() only works to one level of property access, no chains yet.