Flashing Data to Session in Laravel: Explained with Examples

Introduction

Flashing data to the session is a crucial part of web application development. It allows developers to pass temporary data between requests — typically status messages or error details on form submissions. Laravel, as a comprehensive and modern PHP framework, provides a simple and elegant way to manage session data. In this guide, we will dive into how to flash data to the session in Laravel and explore its various applications through practical examples.

Flashing Data to Session Basics

In Laravel, flashed session data is used to store information for only one request cycle. This means that flashed data will only be available on the next HTTP request and will then be deleted. This feature is handy for passing success or error messages to views after redirecting the user.

// Flash a message to the session
request()->session()->flash('status', 'Task was successful!');

The above code will flash status into the session. The directive requests() provides access to the current HTTP request instance, and the session() method gives a way to interact with session data.

Basic Example with Redirect

One common scenario is redirecting the user after a form submission and displaying a one-time message:

public function store(Request $request)
{
    // Handle the form submission...

    // Flash a success message
    $request->session()->flash('success', 'Your form was submitted!');

    // Redirect to a given URL
    return redirect('form')->with('success', 'Your form was submitted!');
}

The with() method used during redirect is a shortcut to flash data. It achieves the same outcome as the flash() method, providing an expressive syntax.

Displaying Flashed Messages

To display flashed messages, you typically use blade templates like so:

<!-- Check for a flashed success message -->
@if(session('success'))
    <div class="alert alert-success">
        {{ session('success') }}
    </div>
@endif

This snippet checks for the existence of a success message in the session, and if it exists, it displays it within a styled div.

Flash Data for Validation Errors

Laravel also provides an easy way to flash error messages for form validation:

public function store(Request $request)
{
    // Validate the request...
    $validatedData = $request->validate([
        'email' => 'required|email',
        'password' => 'required|min:6',
    ]);

    // Further processing...
}

If the validation fails, the errors are automatically flashed to the session and the user is redirected back to the previous form, enabling easy error message display.

Advanced: Flash Data Across Multiple Requests

There are cases where you might need to keep flash data for several requests. Laravel provides the reFlash() and keep() methods:

public function showTemporaryMessage(Request $request)
{
    // First Request
    $request->session()->flash('message', 'This is temporary');

    // Further into the lifecycle, preserving flash message
    $request->session()->keep(['message']);
}

The keep() method requires specifying which flashed session keys you want to retain for the next request, thereby extending their life.

Flashing Data with Redirects

For convenience, Laravel allows you to chain multiple flash operations on a redirect:

return redirect('home')->with(['success' => 'You are now logged in.', 'status' => 'Welcome back!']);

By using array syntax within the with() method, you can flash multiple pieces of data to the session in a fluent and readable way.

Conclusion

In conclusion, flashing data to the session in Laravel is a powerful feature that helps create a seamless user experience. Whether it’s for displaying form submission confirmations or passing error messages, Laravel simplifies the process with its expressive and convenient syntax. The examples provided in this guide serve as a foundation for effectively using session flashing to enhance interaction within your Laravel applications.