Cloud functions for firebase - deleted or added data

I want to distinguish between deleted and data that was first created. I´m using the code from Firebase:

if (event.data.previous.exists()) {
    return;
  }
  // Exit when the data is deleted.
  if (!event.data.exists()) {
    return;
  }

However, it doesn't work. I´m listening to the database which is structured as following:

• in use
  • fruitID
  • id: fruitID

I want to use code when the data is deleted and another code when the data is created, so when a fruit is added.

Using the given code only the part in

if (event.data.previous.exists()){
}

is executed AND ALWAYS when the data is DELETED.

Any suggestions?

Thanks.

via ktm125