Subscription model using symfony3 - security

Question

I'm trying to set up a subscription site using symfony. I want to be able to offer say 3 articles free to users with ROLE_USER but then direct them to a subscribe option if they want to view more articles. I'm having trouble figuring out how to implement this with the security system.
I suspect I'll need a custom voter. Is that the route I should be looking? Then perhaps a custom access.denied.handler as well.
I'm mostly unsure about how to implement this using voters. Is that the way to go?

Answer 1

If they will need to login (as you talk about Roles then they will probably need) then you can do it with request listener and de-increment number of free articles on every article page load (or if you want to allow refreshing article page without touching limit again then you will need to implement some storage for user-read-articles and disable free reading after opening 3 different articles by user).
You need to implement request event listener (read more about events here: http://symfony.com/doc/current/components/http_kernel/introduction.html#the-kernel-request-event):
<?php
namespace App\AppBundle\EventListener;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\HttpKernelInterface;
class FreeReadingListener
{
/**
* #param GetResponseEvent $event
*/
public function onKernelRequest(GetResponseEvent $event)
{
if (HttpKernelInterface::MASTER_REQUEST !== $event->getRequestType()) {
// don't do anything if it's not the master request
return;
}
// check if loaded route is article route
// check if user can read articles for free (can be as some kind flag) - if can't then redirect to subscriptions page
// log user article read
// if user used limit - switch free reading flag on user
}
}
services.yml
services:
app_bundle.listener.free_reading:
class: App\AppBundle\EventListener\FreeReadingListener
tags:
- { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }
Listener docs: http://symfony.com/doc/current/cookbook/event_dispatcher/event_listener.html