<?php
class Composable {
    private $behaviors = array();
 
    public function __call($name, $arguments) {
        foreach ($this->behaviors as $behavior) {
            if ($behavior->provides($name)) {
                return $behavior->invoke($this, $name, $arguments);
            }
        }
 
        throw new Exception("No method $name and no behavior that implements it!");
    }
 
    public function attach($behavior) {
        $this->behaviors[] = $behavior;
    }
}
 
class User extends Composable {
}
 
abstract class Behavior {
    public function provides($name) {
        return method_exists($this, $name);
    }
 
    public function invoke($target, $name, $arguments) {
        array_unshift($arguments, $target);
        return call_user_func_array(array($this, $name), $arguments);
    }
}
 
class GrouppableBehavior extends Behavior {
    public function join(User $user, $groupName) {
        echo "The user has joined group $groupName.";
    }
}
 
$user1 = new User;
$user2 = new User;
 
$user1->attach(new GrouppableBehavior);
$user1->join('Test Group');
$user2->join('Test Group');
 

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