On the [Firebase docs](https://firebase.google.com/docs/reference/functions/functions.database.RefBuilder#onCreate) they mention 4 types of triggers: 

* onCreate
* onDelete
* onUpdate
* onWrite

Is there a way to listen to added row in the Cloud Functions and modify fields of an added row before the "child\_added" listeners are triggered? Is there a way to implement BeforeCreate?

Desired BeforeCreate cycle (in Cloud Functions):

* Request to add a new message
* Change the message fields
* Add a new message with modified fields
* Clients receive a "child\_added" event