ValueEventListener

public interface ValueEventListener

Classes implementing this interface can be used to receive events about data changes at a location. Attach the listener to a location user addValueEventListener.

Summary

Public methods
abstract void

This method will be triggered in the event that this listener either failed at the server, or is removed as a result of the security and Firebase Database rules.
abstract void

This method will be called with a snapshot of the data at this location.

Public methods

onCancelled

abstract void onCancelled(@NonNull DatabaseError error)

This method will be triggered in the event that this listener either failed at the server, or is removed as a result of the security and Firebase Database rules. For more information on securing your data, see: Security Quickstart

Parameters
@NonNull DatabaseError error

A description of the error that occurred

onDataChange

abstract void onDataChange(@NonNull DataSnapshot snapshot)

This method will be called with a snapshot of the data at this location. It will also be called each time that data changes.

Parameters
@NonNull DataSnapshot snapshot

The current data at the location