Add additional parameters into event subscriber - symfony

Question

I am using symfony 3. I already created some events and they work fine. But this new event is different. I must somehow send some additional parameters to subscriber. What is the best way to do that? I created phenstalk service to perform job. The controller dispatch an event like:
$dispatcher = $this->container->get('event_dispatcher');
$dispatcher->dispatch(Events::POWERPLANT_GET_DATA, new PowerPlantEvent($this->getPowerPlantAction($id)));
Call like this will not work, cuz I am missing some parameters.
and I have action in subscriber:
public function onPowerPlantGetData(PowerPlantEvent $event, $startDate, $endDate, $measurement, $field)
How to do that?

Answer 1

If you event uses optional parameters, you can make them optional in the constructor.
use Symfony\Component\EventDispatcher\Event;
final class PowerPlantEvent extends Event
{
/**
* #var PowerPlantAction
*/
private $powerPlantAction;
/**
* #var \DateTime
*/
private $startDate;
/**
* #var \DateTime
*/
private $endDate;
/**
* #var int
*/
private $measurement;
/**
* #var string
*/
private $field;
public function __construct(
$powerPlantAction,
$startDate = null,
$endDate = null,
$measurement = null,
$field = null
) {
$this->powerPlantAction = $powerPlantAction;
$this->startDate = $startDate;
$this->endDate = $endDate;
$this->measurement = $measurement;
$this->field = $field;
}
public function getPowerPlantAction()
{
return $this->powerPlantAction;
}
public function getStartDate()
{
return $this->startDate;
}
public function getEndDate()
{
return $this->endDate;
}
public function getMeasurement()
{
return $this->measurement;
}
public function getField()
{
return $this->field;
}
}
Then dispatching like this:
$this->eventDispatcher->dispatch(
Events::POWERPLANT_GET_DATA,
new PowerPlantEvent($this->getPowerPlantAction($id))
);
Or:
$this->eventDispatcher->dispatch(
Events::POWERPLANT_GET_DATA,
new PowerPlantEvent(
$this->getPowerPlantAction($id),
$startDate,
$endDate,
$measurement,
$field
)
);
In your subscriber just use those getters:
public function onPowerPlantGetData(PowerPlantEvent $powerPlantEvent)
{
$powerPlantEvent->getStartDate();
// ...
}

Answer 2

You should put all necessary data into Event itself and then you can access them in subscriber
For simplicity I made properties public and added all to __construct but it's up to you how you implement it. You might want to create new Event class for that
class PowerPlantEvent extends Event
{
/**
* #var \DateTime
*/
public $startDate;
/**
* #var \DateTime
*/
public $endDate;
/**
* #var Something
*/
public $measurement;
public $field;
/**
* PowerPlantEvent constructor.
*
* #param \DateTime $startDate
* #param \DateTime $endDate
* #param Something $measurement
* #param $field
*/
public function __construct(\DateTime $startDate, \DateTime $endDate, Something $measurement, $field)
{
$this->startDate = $startDate;
$this->endDate = $endDate;
$this->measurement = $measurement;
$this->field = $field;
}
}
and call it with
$dispatcher = $this->container->get('event_dispatcher');
$dispatcher->dispatch(
Events::POWERPLANT_GET_DATA,
new PowerPlantEvent($startDate, $endDate, $measurement, $field)
);
and access in subscriber (or event listener)
public function onPowerPlantGetData(PowerPlantEvent $event)
{
$startDate = $event->startDate; // you might want to implement getters for those
}