Question

I’m working with PHPRO’s MVC framework and am having problems passing a Registry object to my controller class.

In my Router class, the loadController() method determines which controller to load and instantiates it. In the process, it passes the controller a Registry object that contains, among other things, a Template object:

class Router
{
    private $registry;                // passed to Router's constructor
    public $file;                     // contains 'root/application/Index.php'
    public $controller;               // contains 'Index'

    public function loadController()
    {
        $this->getController();       // sets $this->file, $this->controller
        include $this->file;          // loads Index controller class definition
        $class = $this->controller;
        $controller = new $class($this->registry);
    }
}

From Xdebug, I know that Router’s $registry property has everything it’s supposed to prior to being passed as an argument to Index’s constructor.

However, $registry fails to make it to Index intact. Here are the class definitions for Index and its parent Controller:

abstract class Controller
{
    protected $registry;

    function __construct($registry)
    {
        $this->registry = $registry;
    }
    abstract function index();
}

class Index extends Controller
{
    public function index()
    {
        $this->registry->template->welcome = 'Welcome';
        $this->registry->template->show('index');
    }
}

With the code as shown, I get this error message: “Call to undefined method stdClass::show() in …Index.php”.

Within Index, Xdebug shows $registry as null, so I know it’s inheriting from the parent. But somewhere between the code to create a new Index object and the Index class definition, $registry gets lost.

While debugging, I found that eliminating the Controller class from the equation stops the error from occurring:

class Index // extends Controller
{
    private $registry;

    function __construct($registry)
    {
        $this->registry = $registry;
    }

    public function index()
    {
        $this->registry->template->welcome = 'Welcome';
        $this->registry->template->show('index');
    }
}

Of course, this doesn’t really solve anything because I still need the Controller class, but hopefully it will help as a clue to the problem.

Can anyone see why I’m losing the contents of $registry when it gets passed to Index?

Answer 1

This should work :

class Index extends Controller
{
    public function __construct( $registry )
    {
         parent::__construct( $registry );
    }

    public function index()
    {
        $this->registry->template->welcome = 'Welcome';
        $this->registry->template->show('index');
    }
}

In PHP the constructors are not inherited.

Aadditionally , you might benefit from watching this video and some other of the series : The Clean Code Talks – Don’t Look For Things! .