Hello,

I’m assuming that you’re talking about onDataChange method of the DataChangeListener interface. Please, tell if that assumption is incorrect.

There is no way to avoid triggering onDataChange of a DataChangeListener in specific situations such as when the Client is connected to the Server for the first time. This applies to listeners in general as well. Instead, if you need to use prevValue in your code, you should add a null check to it to handle it being null when there are no previous values.