Event Handlers

HTTP event streaming is implemented in the PowerMedia WMS EventHandler resource.

When the client wishes to receive asynchronous events, it uses the web service to create an EventHandler and subscribes to specific event types. When the client performs an HTTP GET on the newly created EventHandler, the web service responds with a 200 OK; however, the TCP connection remains open until the client destroys the EventHandler. Event data related to resources and event types subscribed to will be pushed to the client until the Eventhandler is deleted by the client.

XML Definition

<eventhandlers size="<size>">
    <eventhandler identifier=" <identifier> "appid=" <appid> "
    href="http://server/dialogicwebservice/mediacontrol/eventhandlers/<identifier>" >
    <eventsubscribe resourceid="<resourceid>"  resourcetype="< resourcetype> "
      type="<eventtype>">
      </eventsubscribe>
      </eventhandler>
     ...
</eventhandlers>

<event type="<eventtype>" data="<data>" resourceid="<resourceid>"
    resourcetype="< resourcetype>" >
</event>

Properties

EventHandler Properties

Name	Description	Type	Input / Output	Optional / Mandatory
identifier	Unique identifier assigned to the specific instance of the resource. This identifier is used by the web service client when performing actions on the resource.	String	Output	N/A
appid	Unique application id included in the original HTTP POST creation process that is utilized by the web service such that clients only have access to resources that they created.	String	Output	N/A
href	An HTTP reference to the specific resource.	String	Output	N/A

EventSubscribe Properties

Name	Description	Type	Input / Output	Optional / Mandatory
resourceid	Unique resource identifier to monitor for events. Default:Any	String	Input / Output	Optional
resourcetype	Type of resource to monitor for events, such as player, collector. Supported resource types: “player” “recorder” “collector” “playercollector” and “any”. “any” means all the supported resource types. Default: any	String	Input / Output	Optional
type	Event type to monitor, such as such as play complete, dtmf. Supported event types: “play_complete” “record_complete” “dtmf” , “keepalive” and “any”. The “keepalive” event will be sent every five mins after being subscribed. "any” means all the supported event types. Default: any	String	Input / Output	Optional
action	Add or remove the event subscribe: add, remove. Default: add	String	Input/Output	Optional

Event Properties

Name	Description	Type	Input / Output	Optional / Mandatory
type	Event type	String	Output	N/A
data	Event data	String	Output	N/A
resourceid	IP of resource sending event	String	Input	N/A
resourcetype	Type of resource	String	Output	N/A

Interaction Diagram

Event Handler Sequence Diagram

The following diagram illustrates the event handler sequence.

Java Sample Code

    public void CreateEventHandler() {
        logger.info("EventMonitor:: CreateEventHandler - Entered.");
        //Create a HttpURLConnection with the correct server
        //Send request to create event handler and retrieve response
        String response = "";
        String requestBody = "<eventhandler>\r\n" +
                             "/t<eventsubscribe type=\"any\" resourceid=\"any\"/>\r\n" +
                             "</eventhandler>";
        HttpURLConnection connection = utils.SendHTTPRequest("http://" +
        MainSipServlet.WMSHost + ":81/DialogicWebService/mediacontrol/eventhandlers",
                                                             "POST",
                                                             requestBody);
        if (connection != null) {
            response = utils.GetHTTPStringResponse(connection);
        }
        //Retrieve response codes
        int responseCode = 0;
        try {
            responseCode = connection.getResponseCode();
        } catch (IOException ex) {
            Logger.getLogger(EventMonitor.class.getName()).log(Level.SEVERE, null, ex);
        }
        String responseMessage = "";
        try {
            responseMessage = connection.getResponseMessage();
        } catch (IOException ex) {
            Logger.getLogger(EventMonitor.class.getName()).log(Level.SEVERE, null, ex);
        }
        String responseLocation = connection.getHeaderField("location");
        //close the connection
        connection.disconnect();
        //log results
        logger.info("EventMonitor:: CreateEventHandler - Http response code =" +
         responseCode);
        logger.info("EventMonitor:: CreateEventHandler - Http response message =" +
        responseMessage);
        logger.info("EventMonitor:: CreateEventHandler - Http response location =" +
        responseLocation);
        if (responseCode == 201) {
            eventHandlerRef = responseLocation;
        }
        logger.info("EventMonitor:: CreateEventHandler - Exited.");
    }