class PostHandler{
        private $data;
        private $current;

        public function __set($key, $value){
            $this->data[$key] = $value;
        }

        public function __get($key){
            $this->current = $this->data[$key];
            return $this;
        }

        public function submit(){
            echo 'Posting message: ' . $this->current;
        }
    }

    $postHandler = new PostHandler();
    $postHandler->vincent = 'vincent';
    $postHandler->vincent->submit();