Failing to pass variables from controller to view

Question

I am trying to pass values from the controller to the view to a drop down menu. I got the code to work without MVC architecture, but I don't know how to pass the data from the controller to the view in MVC. So I don't know how to pass the variable to the View.

ReadCategories: class ReadCategories { private $db;

public function __construct($pdoConnection) {
    $this->db = $pdoConnection;
}

public function getCategories() {
    try {
        $query = $this->db->prepare("SELECT * FROM categories");
        $query->execute();
        return $query->fetchAll(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        error_log("Error fetching categories: " . $e->getMessage());
        return [];
    }
}

}

CategoryController: class CategoryController { private $readCategories;

public function __construct(ReadCategories $readCategories) {
    $this->readCategories = $readCategories;
}

public function handleRequest() {
    session_start();

    if (!isset($_SESSION['username']) || empty($_SESSION['username'])) {
        header("Location: /technique-db/app/MVC/View/LoginView.php");
        exit();
    }

    $categories = $this->readCategories->getCategories();

    include __DIR__ . '/../View/AddItemsView.php';
}

}

$pdoConnection = require __DIR__ . '/../Config/db.php'; // Include the database connection file and get the PDO connection

// Check if the database connection is a valid PDO instance
if (!$pdoConnection instanceof PDO) {
    echo "Database connection failed.";
    exit(); // Terminate the script if the database connection failed
}

$readCategories = new ReadCategories($pdoConnection);

// Route to CategoryController if requested
if (isset($_GET['action']) && $_GET['action'] === 'additems') {
    $categoryController = new CategoryController($readCategories);
    $categoryController->handleRequest();
    exit();
}

// Create a new LoginUser object with the PDO connection
$loginUser = new LoginUser($pdoConnection);
// Create a new IndexController object with the LoginUser object
$indexController = new IndexController($loginUser);
// Handle the request
$indexController->handleRequest();

Answer 1

It is not a best practice but you have to make $categories global

global $categories;

$categories = $this->readCategories->getCategories();

you should also make global in included file