AppException

render404()

This method is used to display a 404 error page when a resource is not found. It checks the debug mode and displays detailed information if debug mode is enabled; otherwise, it displays a general message.

• Sets the HTTP response code to the error code (404).

• If debug mode is enabled, it displays detailed error information including the error code, error message, file, line, and trace.

• If debug mode is disabled, it displays a general 404 error message.

• Uses the Render class to display the 404 error page.

• Stops further execution using exit().

Example:

$exception = new AppException("Page not found", 0, null, 404);
$exception->handle();

renderError()

This method is used to display exception information in HTML format for the user. It also checks the debug mode and displays detailed information if debug mode is enabled; otherwise, it displays a general message.

• Sets the HTTP response code to the error code (500 or other error codes).

• If debug mode is enabled, it displays detailed error information including the error code, error message, file, line, and trace.

• If debug mode is disabled, it displays a general error message.

• Stops further execution using exit().

$exception = new AppException("Internal Server Error", 0, null, 500);
$exception->handle();

handle()

This method handles the exception, logs it, and displays the error information to the user. It checks the error status code and calls the corresponding method (render404 or renderError).

• Logs the error using the Logger class.

• Checks the error status code:

  • If it is 404, calls the render404() method.

  • If it is another error code, calls the renderError() method.

Example:

try {
    // Some code that may throw an exception
    throw new AppException("Page not found", 0, null, 404);
} catch (AppException $e) {
    $e->handle();
}

Using in Controller

<?php
namespace App\Controllers;

use System\Core\BaseController;
use System\Core\AppException;

class UserController extends BaseController {

    public function index() {
        try {
            // Simulate an error (e.g., user not found)
            $user = $this->findUserById(1);
            if (!$user) {
                throw new AppException('User not found!', 0, null, 404);
            }

            // Render the user data
            $this->render('user/profile', ['user' => $user]);

        } catch (AppException $e) {
            // Handle the exception
            $e->handle();
        }
    }

    private function findUserById($id) {
        // Sample method to simulate user fetching; returns null to simulate "user not found"
        return null;
    }
}

How It Works:

• try {} → Starts the error-handling block.

• Attempts to find the user using findUserById(1).

• If the user is not found (null), throws an AppException with the message "User not found!" and error code 404.

• If no error occurs, renders the user profile page using render('user/profile', ['user' => $user]).

• catch (AppException $e) {} → If an error occurs, it is handled by calling $e->handle();, which may log the error or display an error page.