Universal Messaging 10.1 | Developer Guide | Enterprise APIs | Enterprise Developer's Guide for C# | Publish / Subscribe using Datastreams and Datagroups | Enabling DataGroups and Receiving Event Callbacks
Enabling DataGroups and Receiving Event Callbacks
If an nSession is created with an nDataStreamListener then it will receive asynchronous callbacks via the onMessage implementation of the nDataStreamListener interface. The nDataStreamListener will receive events when:
*An event is published directly to this particular nDataStream
*An event is published to any nDataGroup which contains this nDataStream
*An event is published to an nDataGroup which contains a nested nDataGroup containing this nDataStream
*An example of how to create a session with an nDataStreamListener interface is shown below:

public class DataGroupClient : nDataStreamListener{

nSession mySession;

public DataGroupClient( string realmURLs){
nSessionAttributes nsa = new nSessionAttributes(realmURLs);
mySession = nSessionFactory.create(nsa, this);

// nDataStreamListener Implementation

//Callback received when event is available
public void onMessage(nConsumeEvent event){

//some code to process the message