ValueEventListener

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 functions
`Unit`	`onCancelled(error: DatabaseError)` 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.
`Unit`	`onDataChange(snapshot: DataSnapshot)` This method will be called with a snapshot of the data at this location.

Public functions

onCancelled

fun onCancelled(error: DatabaseError): Unit

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
`error: DatabaseError`	A description of the error that occurred

onDataChange

fun onDataChange(snapshot: DataSnapshot): Unit

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
`snapshot: DataSnapshot`	The current data at the location