How to add a calculated field in the FormEvents::PRE_SUBMIT Event - events

Question

In my listener I need to access my entity when in the FormEvents::PRE_SUBMIT event. In POST_SET_DATA this is no problem, just use $event->getData();.
So for the event listening to POST_SET_DATA I am fine with this code:
public function postSetData(FormEvent $event)
{
$form = $event->getForm();
$day = $event->getData();
$total = $this->dayManager->calculateTotal($day); // Passing a Day object, yay!
$form->get('total')->setData($total);
}
However in my method for the PRE_SUBMIT event.
I need this function because on submitting, total is not calculated with the newly submitted data.
public function preSubmit(FormEvent $event)
{
$form = $event->getForm();
// $day = $event->getData();
// Raw array because $event->getData(); holds the old not updated Day object
$day = $form->getData();
// Ough! Had to create and call a seperate function on my dayManager that handles the raw event array
$total = $this->dayManager->calculateTotalFromArray($event->getData());
// Modify event data
$data = $event->getData();
// Ough(2)! Have to do nasty things to match the raw event array notation
$totalArray = array(
'hour' => $total->format('G') . "",
'minute' => intval($total->format('i')) . ""
);
$data['total'] = $totalArray;
$event->setData($data);
}
As you can see, it works. However this is such a hackish way, I do not believe the pro's do it this way. Two things that go wrong here:
Cannot work with entity Day object in the preSubmit function
Have to create the calculateTotalFromArray function in the dayManager
Ugly code to match the raw event array in the preSubmit function
So the main question: how to get an updated Day object from the form in the PRE_SUBMIT form event.

Answer 1

Use SUBMIT instead of PRE_SUBMIT
Don't worry, the form is not yet submitted, SUBMIT is executed right before Form::submit
Why are you having this problem?
All data in PRE_SUBMIT has not been normalized into your usual object...
If you'd like to learn more about the whole thing, please head to: http://symfony.com/doc/current/components/form/form_events.html

Answer 2

Thanks #galeaspablo for submitting the answer! However I add below my code how I solved my particular problem.
My goal was to show a calculated total field in a form. Nothing more. However in the SUBMIT event you cannot do a $form->get('total')->setData($total);. You will get a warning: You cannot change the data of a submitted form.
So altering a form after PRE_SUBMIT is not possible. But adding fields is..
My complete solution is as follows:
In the DayType formbuilder:
// Will add total field via subscriber
//->add('total', TimeType::class, ['mapped' => false])
In the event subscriber:
class CalculateDayTotalFieldSubscriber implements EventSubscriberInterface
{
private $dayManager;
public function __construct(DayManager $dayManager)
{
$this->dayManager = $dayManager;
}
public static function getSubscribedEvents()
{
return array(
FormEvents::SUBMIT => 'addTotalField',
FormEvents::POST_SET_DATA => 'addTotalField'
);
}
public function addTotalField(FormEvent $event)
{
$form = $event->getForm();
$day = $event->getData();
$total = $this->dayManager->calculateTotal($day);
$form->add('total', TimeType::class, ['mapped' => false, 'data' => $total]);
}
}
Note the use of the save function for both the SUBMIT and the POST_SET_DATA events. A good read was: http://symfony.com/doc/current/components/form/form_events.html