private $view;
    private $model;
    public function __construct()
    {
        $this->view = View::getInstance();
        $this->model = Model::getInstance();
    }
    public function processdata($POST)
    {
        if (empty($_POST)) {
            $this->view->display("default", "");
            //no json data yet
        } else {
            if (isset($POST['category'])) {
                foreach ($POST['category'] as $i => $value) {
                    $this->model->check($value);
                    //value holds the actual index of selection
                }
            }
            $this->model->setLimit($POST['limit']);
            $this->model->setRadius($POST['radius']);
            $this->model->setLatLng($POST['lat'], $POST['lng']);
            $json = $this->model->execute();
            $this->view->display("default", $json);
            //print_r($this->model->getData());
        }
    }
}
$controller = new Controller();
$controller->processData($_POST);