Symfony: Tracking Anonymous Users Between Sessions

Symfony Anonymous User Tracking Between Sessions

Symfony doesn’t have a ready-made bundle for tracking anonymous users between sessions, but there are several approaches to implement this functionality using standard components and third-party solutions. The main methods include creating a unique token for guests, using stored cookies, and integrating with the security system to identify users across different devices.

Table of Contents

• Possible Solutions in Symfony
• Main Approaches to Tracking Anonymous Users
• Technical Implementation
• Recommended Bundles and Tools
• Information Search and Best Practices

Possible Solutions in Symfony

In Symfony, there is no built-in component specifically designed for tracking anonymous users between sessions, but the platform provides flexible tools for creating such functionality. The main approach is to create a guest identification system that allows linking actions of the same anonymous user across different sessions.

For implementing this task, standard Symfony components are used:

• Session component - for storing guest action information
• Security component - for managing authentication tokens
• Cookie component - for preserving user identifiers between sessions

As noted in the Symfony Sessions documentation, sessions allow storing user information between requests, which is the foundation for guest identification.

Main Approaches to Tracking Anonymous Users

Token-based Approach

The most reliable and widely used method is creating a unique token for each anonymous user:

1. On the first visit to the site, a random token is generated
2. The token is saved in the database with guest action information
3. The token is written to the user’s browser cookie
4. On subsequent visits, the token is read from the cookie and used for user identification

As recommended on StackOverflow, “store actions and link them to a unique token that you send to the anonymous user. After authentication, they can provide the generated token, and then you save the actions for that user.”

Using sessionId

An alternative approach is to use the session identifier (PHPSESSID) for identification:

$sessionId = $request->getSession()->getId();

However, this method has limitations, as noted in discussions on StackOverflow: “using IP address for this is not recommended as it can cause problems for users behind NAT. Using a special cookie or sessionId cookie as an identifier for tracking would be a better idea.”

“Remember Me” Approach

For longer tracking, you can use the “Remember Me” mechanism, which creates a long-lasting cookie:

# config/packages/security.yaml
security:
    firewalls:
        main:
            remember_me:
                secret: '%kernel.secret%'
                lifetime: 31536000 # 1 year
                path: /

Technical Implementation

Creating a Guest User

First, let’s create a service for managing guest users:

// src/Service/GuestUserService.php
namespace App\Service;

use App\Entity\GuestUser;
use Doctrine\Persistence\ManagerRegistry;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\HttpFoundation\Cookie;

class GuestUserService
{
    private $doctrine;
    private $requestStack;
    
    public function __construct(ManagerRegistry $doctrine, RequestStack $requestStack)
    {
        $this->doctrine = $doctrine;
        $this->requestStack = $requestStack;
    }
    
    public function getGuestUser(): GuestUser
    {
        $request = $this->requestStack->getCurrentRequest();
        $guestToken = $request->cookies->get('guest_token');
        
        if ($guestToken) {
            $guestUser = $this->doctrine->getRepository(GuestUser::class)->findOneBy([
                'token' => $guestToken
            ]);
            
            if ($guestUser && !$guestUser->isExpired()) {
                return $guestUser;
            }
        }
        
        // Create new guest user
        return $this->createGuestUser();
    }
    
    private function createGuestUser(): GuestUser
    {
        $guestUser = new GuestUser();
        $guestUser->setToken(bin2hex(random_bytes(32)));
        $guestUser->setCreatedAt(new \DateTime());
        $guestUser->setExpiresAt(new \DateTime('+30 days'));
        
        $this->doctrine->getManager()->persist($guestUser);
        $this->doctrine->getManager()->flush();
        
        return $guestUser;
    }
}

Setting up middleware

Create middleware for setting the guest token cookie:

// src/Middleware/GuestTokenMiddleware.php
namespace App\Middleware;

use App\Service\GuestUserService;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Event\ResponseEvent;

class GuestTokenMiddleware
{
    private $guestUserService;
    
    public function __construct(GuestUserService $guestUserService)
    {
        $this->guestUserService = $guestUserService;
    }
    
    public function onKernelResponse(ResponseEvent $event)
    {
        $request = $event->getRequest();
        $response = $event->getResponse();
        
        // Only for new sessions
        if ($request->getSession()->isStarted() && !$request->cookies->has('guest_token')) {
            $guestUser = $this->guestUserService->getGuestUser();
            $cookie = new Cookie(
                'guest_token',
                $guestUser->getToken(),
                $guestUser->getExpiresAt(),
                '/',
                null,
                false,
                false,
                false,
                'Lax'
            );
            $response->headers->setCookie($cookie);
        }
    }
}

Integration with the security system

To integrate with Symfony Security, create a custom user:

// src/Security/GuestUser.php
namespace App\Security;

use Symfony\Component\Security\Core\User\UserInterface;

class GuestUser implements UserInterface
{
    private $id;
    private $token;
    
    public function getRoles(): array
    {
        return ['ROLE_GUEST'];
    }
    
    public function getPassword(): ?string
    {
        return null;
    }
    
    public function getSalt(): ?string
    {
        return null;
    }
    
    public function eraseCredentials(): void
    {
        // Nothing to do for guest user
    }
    
    public function getUserIdentifier(): string
    {
        return $this->token;
    }
    
    // Getters and setters for fields
}

Recommended Bundles and Tools

Third-party bundles

Although there’s no built-in solution, there are third-party bundles that can simplify implementation:

1. FOSUserBundle - provides a user management system, including guests
2. HWIOAuthBundle - for integration with social networks
3. LexikJWTAuthenticationBundle - for JWT token authentication

Custom solutions

For advanced features, it’s recommended to create your own bundle:

php bin/console make:bundle GuestTrackingBundle

Alternative approaches

1. Analytics systems - such as Google Analytics or Matomo provide ready-made solutions for user tracking
2. Customer Data Platforms - for more complex scenarios
3. Temporary session databases - for storing guest action history

Information Search and Best Practices

Key search terms

For searching information on this topic, use the following keywords in English:

• “Symfony anonymous user tracking”
• “Symfony guest user identification”
• “Symfony session persistence”
• “Symfony token-based authentication”
• “Symfony remember me functionality”

Recommended resources

1. Symfony Session Documentation - foundation for understanding session mechanisms
2. StackOverflow discussions - practical implementation examples
3. Symfony Security Component - for understanding the security system

Best practices

1. Security - always encrypt sensitive data in cookies
2. Performance - use caching for frequently requested guest data
3. Privacy - comply with GDPR and other data protection regulations
4. Scalability - design the system to handle large numbers of anonymous users

Conclusion

There is no built-in solution in Symfony for tracking anonymous users between sessions, but the platform provides all the necessary tools to create such functionality. The main approaches include token-based identification, using sessionId, and “Remember Me” mechanisms.

For practical implementation, it’s recommended to:

• Create a system for generating and storing unique tokens for guests
• Implement middleware for managing cookies with identifiers
• Integrate with Symfony’s security system for a consistent approach
• Use existing bundles to simplify development

When searching for information, use terms like “anonymous user tracking”, “guest identification”, and “session persistence” combined with “Symfony” to get the most relevant results.

Sources

1. Sessions (Symfony 7.3 Documentation)
2. Symfony 2 track anonymous user actions in database - Stack Overflow
3. Persistence of sessions Symfony 3 - Stack Overflow
4. Symfony 4, Identify between anonymous user and user whose session has been killed - Stack Overflow
5. Storing data on an “anonymous” user - Stack Overflow
6. Avoid Starting Sessions for Anonymous Users - Symfony
7. Security (Symfony Documentation)