Flash

The Flash Messages middleware in Lithe allows you to store and retrieve temporary messages between requests.

Installing the Flash Messages Middleware

To install the Flash Messages middleware, use Composer:

composer require lithemod/session

You can find more information and the source code for the module at github.com/lithemod/session.

Using the Flash Messages Middleware

The Flash Messages middleware in Lithe allows you to store temporary messages in the session, which can be accessed on the next request. This is useful for displaying status messages, such as confirmations or errors, after an operation.

Configuring the Flash Middleware

To use the Flash Messages middleware, add it to your application using the use() method:

use Lithe\Middleware\Session\flash;

$app->use(flash());

Setting Flash Messages

To set a flash message, you can use the magic __set method or the set method of the Flash class. Both approaches store the message in the session so that it is available on the next request.

Using the magic __set method:

$app->get('/set-message', function ($req, $res) {
    $req->flash->successMessage = 'Operation completed successfully!';
});

Using the set method:

$app->get('/set-message', function ($req, $res) {
    $req->flash->set('successMessage', 'Operation completed successfully!');
});

Retrieving Flash Messages

To retrieve and remove a flash message from the session, you can use the magic __get method or the get method of the Flash class. These messages are removed from the session after they are retrieved.

Using the magic __get method:

$app->get('/get-message', function ($req, $res) {
    $message = $req->flash->successMessage;
    echo $message; // Displays the message
});

Using the get method:

$app->get('/get-message', function ($req, $res) {
    $message = $req->flash->get('successMessage');
    echo $message; // Displays the message
});

Checking Flash Messages

To check if one or more flash messages exist in the session, use the has method:

Single Check:

$app->get('/check-message', function ($req, $res) {
    $exists = $req->flash->has('successMessage');
    echo $exists ? 'Message exists!' : 'Message does not exist.';
});

Multiple Checks:

$app->get('/check-messages', function ($req, $res) {
    $exists = $req->flash->has(['successMessage', 'errorMessage']);
    echo $exists ? 'Messages exist!' : 'No messages exist.';
});

Keeping Flash Messages

If you want to keep a flash message for the next request (i.e., make it available in more than one request), use the keep method:

$app->get('/keep-message', function ($req, $res) {
    $req->flash->keep('successMessage');
});

This reconfigures the message for the next request after retrieval.

Considerations

Persistence: Flash messages are removed from the session after the first retrieval unless you use the keep method to preserve them.
Security: Ensure that retrieved messages are sanitized to avoid security issues like XSS attacks. Proper validation and handling of messages are essential to maintain application security.