Firebase Realtime Database Reads Data That Doesnt Exist

we came across what might be a major bug in the firebase database, pls see code below. the code below tries to set a value to a child 'EXAMPLE' which doesnt have a read or write pe

Solution 1:

In the snippet as you share it, most likely the listener is getting the value from the local cache before that cache has been updated because of the rejection from the server.

When you add a listener, Firebase tries to give you the value it expects the node to have immediately. And since you call addListenerForSingleValueEvent, it them immediately stops listening for the value. So you end up seeing only stale value from the local cache, and never see the actual value (or lack thereof) from the server.

For this reason you should not use both disk persistence and addListenerForSingleValueEvent in your app. Using addValueEventListener in the same scenario would lead to two calls to onDataChange: the first one with the value from the local cache, and the second one with the correct snapshot from the server.

For a longer answer on how these work, and why they don't result in the behavior you'd like, see: Firebase Offline Capabilities and addListenerForSingleValueEvent