Attaching PHP Closures/Anonymous Functions a Class/Object

attaching-closures-to-objects-in-php.php

<?php
/**
 * references:
 * http://www.murraypicton.com/2010/09/extending-objects-using-anonymous-functions-in-php/
 * http://php.net/manual/en/functions.anonymous.php
 * http://php.net/manual/en/function.is-callable.php
 */

class Foo {
    public $bar;
    public function __call($method, $args) {
        if(isset($this->$method) === true) {
            $func = $this->$method;
            $func();
        }
    }
}

$obj = new Foo;
$obj->bar = function() {
    echo "Inside Foo::bar()\n";
};

var_dump($obj->bar); // prints out that we have a closure

var_dump(method_exists($obj,'bar')); // return false (WHY!?!?!?!)

var_dump(is_callable(array($obj,'bar'), true, $callable_name)); // returns true

var_dump($callable_name); // prints Foo::bar (even though it isn't a static function)

$obj->bar(); //Will generate a fatal error as the method doesn't exist if we don't have the __call method in Foo

$func = $obj->bar;
$func(); //Outputs "Inside Foo:bar()"

Don't forget about __callStatic() and __isset() for this type of thing. Also, you don't need to get the value:

        return $this->{$method}($args);

or

        return call_use_func_array(array($this, $method), $args);