Where to transform raw data? - symfony

Question

I'm starting a new bundle. Its goal is to display some statistics arrays and charts. The problem is I don' t know where to transform raw data into usable data in view's arrays and charts. I read lot of articles about keeping the controllers as thin as possible. And as far as I know, repositories are meant to extract data, not transform them.
Where am I supposed to transform my raw data, according to Symfony2 best practices?

Answer 1

it depends on your application but based on what you described looks like you need to define a Service and write all your logic there so your controller would look something like this
$customService = $this->get('my_custom_service');
$data = $customService->loadMyData();
read more about Services in Symfony: http://symfony.com/doc/current/book/service_container.html

Answer 2

Simply create your own, custom service that uses some repository/ies to extract the data and transform it into usable form.
Sample:
// repository
interface MyRepository {
public function findBySomething($something);
}
class MyRepositoryImpl extends EntityRepository implements MyRepository {
public function findBySomething($something) {
return $this->createQueryBuilder('a')
->where('a.sth = :sth')
->setParameter('std', $something)
->getQuery()
->getResult();
}
}
// service
interface MyService {
public function fetchSomeData();
}
class MyServiceImpl implements MyService {
/** #var MyRespostiory */
private $repo;
public function __construct(MyRepository $repo) {
$this->repo = $repo;
}
public function fetchSomeData() {
$rawData = $this->repo->findBySomething(123);
$data = [];
// do sth
return $data;
}
}
// final usage, eg. within a constructor
class MyConstructor extends Controller {
/** #var MyService */
private $myService;
public function __construct(MyService $myService) {
$this->myService = $myService;
}
public function someAction() {
// you could also get access to the service using $this->get('...')
$data = $this->myService->fetchSomeData();
return $this->render('SomeTemplate', [
'data' => $data
]);
}
}
// service declaration
<service id="myService" class="MyServiceImpl">
<argument type="service" id="doctrine.repository.my_repository" />
</service>