Entity without database - symfony

Question

I'm using Symfony 2.7.x
My goals :
1/ A form where the user chooses the figures
2/ Form submitting
3/ Compute something with the help of the submitted data
4/ Display the value
Then I want to create a form, an entity but I don't need any database.
<?php
namespace RD\FicheBundle\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use RD\FicheBundle\Entity\Donnees;
use RD\FicheBundle\Form\DonneesType;
class ThController extends Controller
{
// ... code
public function calculsAction(Request $request)
{
$donnees = new Donnees();
$form = $this->get('form.factory')->create(new DonneesType(), $donnees);
$form->handleRequest($request);
if ($form->isValid())
{
// What should I use right here to get my data from the form?
// ???????????????????????
// My calculation
$monney= $log_num*$surf_num*$ann_num*$chauff_num*$del_num;
$CO2 = 200*$log_num*$surf_num*$ann_num*$chauff_num*$del_num;
// Getting back the data to the template to display them
return $this->render('RDFicheBundle:Th:calculs.html.twig', array(
'form' => $form->createView(),
'monney' => $monney,
'CO2' => $CO2
));
}
// ... code
}
}
?>
How to get the data coming from the form without doing anything with a database? Should I use an entity?

Answer 1

Form arent't expecting any storage/database layer if you dont't tell them to. (like with field types: entity, and options on other ones.)
In your case:
Getting the data from submitted (or unsubmitted) form is simple as
$form->getData()
If you do this after your $form->handleRequest($request); line, you will get submitted data.
You can also check if you form was submitted with $form->isSubmitted(), which return an boolean true/false.
If you want your form to populate the submitted data to associated entity (object), you just need set data_class in your form type like this
/**
* #inheritdoc
*/
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => 'Acme\AppBundle\Entity\Example'
]);
}
data_class option can be set also for separate, fields(types) of your form, if you got some more complex scenario.
These docs should help you here:
http://symfony.com/doc/current/book/forms.html#creating-form-classes
Also here you can see that forms are NOT persisted to db automaticly:
http://symfony.com/doc/current/book/forms.html#forms-and-doctrine