Monitoring NetStream events

Two types of events provide valuable usage data: netStatus and mediaTypeData. In addition, a timer can be used to periodically log the position of the NetStream playhead.

netStatus events provide information you can use to determine how much of a stream a user viewed. Buffer and RTMFP stream transition events also result in a netStatus event.

mediaTypeData events provide meta and XMP data information. The Netstream.Play.Complete event is dispatched as a mediaTypeData event. Other data embedded in the stream are also available through mediaTypeData events, including cue points, text, and images.

The following example illustrates how to create a class that monitors status and data events from any active NetStreams in an application. Typically, such a class would upload the data it was interested in analyzing to a server for collection.

package com.adobe.example
{
    import flash.events.NetDataEvent;
    import flash.events.NetMonitorEvent;
    import flash.events.NetStatusEvent;
    import flash.net.NetMonitor;
    import flash.net.NetStream;

    public class NetStreamEventMonitor
    {
        private var netmon:NetMonitor;
        private var heartbeat:Timer = new Timer( 5000 );

        public function NetStreamEventMonitor()
        {
            //Create NetMonitor object
            netmon = new NetMonitor();
            netmon.addEventListener( NetMonitorEvent.NET_STREAM_CREATE, newNetStream );

            //Start the heartbeat timer
            heartbeat.addEventListener( TimerEvent.TIMER, onHeartbeat );
            heartbeat.start();
        }

        //On new NetStream
        private function newNetStream( event:NetMonitorEvent ):void
        {
            trace( "New Netstream object");
            var stream:NetStream = event.netStream;
            stream.addEventListener(NetDataEvent.MEDIA_TYPE_DATA, onStreamData);
            stream.addEventListener(NetStatusEvent.NET_STATUS, onStatus);
        }

        //On data events from a NetStream object
        private function onStreamData( event:NetDataEvent ):void
        {

            var netStream:NetStream = event.target as NetStream;
            trace( "Data event from " + netStream.info.uri + " at " + event.timestamp );
            switch( event.info.handler )
            {
                case "onMetaData":
                    //handle metadata;
                    break;
                case "onXMPData":
                    //handle XMP;
                    break;
                case "onPlayStatus":
                    //handle NetStream.Play.Complete
                case "onImageData":
                    //handle image
                    break;
                case "onTextData":
                    //handle text
                    break;
                default:
                    //handle other events

            }
        }

        //On status events from a NetStream object
        private function onStatus( event:NetStatusEvent ):void
        {
            trace( "Status event from " + event.target.info.uri + " at " + event.target.time );
            //handle status events
        }
        //On heartbeat timer
        private function onHeartbeat( event:TimerEvent ):void
        {
            var streams:Vector.<NetStream> = netmon.listStreams();
            for( var i:int = 0; i < streams.length; i++ )
            {
                trace( "Heartbeat on " + streams[i].info.uri + " at " + streams[i].time );
                //handle heartbeat event
            }
        }

    }
}