# 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:

```php
$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()`.

```php
$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:

```php
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
<?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.


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