Fixes: #188 handle if _webcamProducer is null

app/src/RoomClient.js

@@ -1136,13 +1136,40 @@ export default class RoomClient
 					}
 				});
 				
+			if(stream){
 				const track = stream.getVideoTracks()[0];
 
+				if (track)
+				{
+					if (this._webcamProducer)
+					{
 						await this._webcamProducer.replaceTrack({ track });
+					}
+					else 
+					{
+						this._webcamProducer = await this._sendTransport.produce({
+							track,
+							appData : 
+							{
+								source : 'webcam'
+							}
+						});	
+					}
+					
 		
 					store.dispatch(
 						producerActions.setProducerTrack(this._webcamProducer.id, track));
+				}
+				else
+				{
+					logger.warn('getVideoTracks Error: First Video Track is null');
+				}
 	
+			}
+			else
+			{
+				logger.warn('getUserMedia Error: Stream is null!');
+			}
 			store.dispatch(settingsActions.setSelectedWebcamDevice(deviceId));
 			store.dispatch(settingsActions.setVideoResolution(resolution));
 
@@ -1194,8 +1221,21 @@ export default class RoomClient
 				const track = stream.getVideoTracks()[0];
 
 				if (track)
+				{
+					if (this._webcamProducer)
 					{
 						await this._webcamProducer.replaceTrack({ track });
+					}
+					else 
+					{
+						this._webcamProducer = await this._sendTransport.produce({
+							track,
+							appData : 
+							{
+								source : 'webcam'
+							}
+						});	
+					}
 		
 					store.dispatch(
 						producerActions.setProducerTrack(this._webcamProducer.id, track));