How to work with the symfony kernel anywhere in Prestashop 1.7

You want to fully tak advantage of symfony in your Prestashop application? Use the symfony kernel! By default, the $kernel variable is only available in the Backoffice section, but here’s a tuto on how to use it also on the Frontoffice. Once the kernel is set up, you can use any symfony services, such as Doctrine, Twig, Monolog! Awesome 😃

Let’s see first how to do it on the backoffice, because it’s a one-liner, and then in the front office, because it requires a little more work. And at the end, we’ll see how to wrap it up in a module, to be always available!

In the backoffice

global $kernel;
// that's it!! Now you can use
$kernel->getContainer()->get('twig')->render(...)

In the frontoffice

The kernel is not set up in the front, but it can be booted with:

require_once _PS_ROOT_DIR_.'/app/AppKernel.php';
$env = 'prod';// or you can use _PS_MODE_DEV_ ? 'dev' : 'prod';
$debug = false;// or you can use _PS_MODE_DEV_ ? true : false;
$kernel = new \AppKernel($env, $debug);
$kernel->boot();
// that's it!! Now you can use
$kernel->getContainer()->get('twig')->render(...)

Refactorisation in a module to be available anywhere

//modules/mymodule/MyModule.php
class MyModule extends Module
{
  public static $kernel = null;
  public static $doctrine = null;
  public static function getKernel()
  {
    // if the singleton doesn't exist
    if (!self::$kernel) {
      // try to load it globally (for backoffice pages)
      global $kernel;
      if ($kernel) {
        self::$kernel = $kernel;
      }
      // otherwise create it manually
      else {
        require_once _PS_ROOT_DIR_ . "/app/AppKernel.php";
        $env = "prod"; //_PS_MODE_DEV_ ? 'dev' : 'prod';
        $debug = false; //_PS_MODE_DEV_ ? true : false;
        self::$kernel = new \AppKernel($env, $debug);
        self::$kernel->boot();
      }
    }
    return self::$kernel;
  }
  public static function getDoctrine()
  {
    if (!self::$doctrine) {
      self::$doctrine = self::getKernel()->getContainer()->get("doctrine")->getManager();
    }
    return self::$doctrine;
  }
  public static function get($service)
  {
    return self::getKernel()->getContainer()->get($service);
  }
}

And use it anywhere:

MyModule::getDoctrine()
MyModule::get('twig')
MyModule::getKernel()->getContainer()->get('twig')