Firebase Functions Error: .once Is Not A Function

I am trying to deploy a simple function to Firebase, but I am having some difficulties. Every time I try to use .once on a reference Firebase tells me that it is not a function. He

Solution 1:

functions.database.ref is a different object than the one you're used to using on the client. It's sole purpose is to listen for writes using it's only function, onWrite.

You can obtain your intended ref thru the event parameter.

var ref = event.data.ref

This is a reference to the path you specified in onWrite.

If you want the root reference:

var rootRef = event.data.ref.root

Further reading: https://firebase.google.com/docs/reference/functions/functions.database