public void SubscribeToNewsHeadlineStream()
{
string searchKeywords = SearchTextBox.Text;
App.ctx.BeginLogIn(App.USERNAME, App.PASSWORD, a =>
{
App.ctx.EndLogIn(a);
//Next we create a connection to the streaming api, using the authenticated session
streamingClient = App.StreamingClient;
streamingClient.Connect();
//And instantiate a listener for news headlines on the appropriate topic
//You can have multiple listeners on one connection
newsListener = streamingClient.BuildNewsHeadlinesListener(searchKeywords);
newsListener.Start();
//The MessageRecieved event will be triggered every time a new News headline is available,
//so attach a handler for that event, and wait until something comes through
NewsDTO recievedNewsHeadline = null;
newsListener.MessageReceived += (s, e) =>
{
recievedNewsHeadline = e.Data;
//Add this new news headline to the main items collection.
ItemViewModel item = new ItemViewModel();
item.Headline = recievedNewsHeadline.Headline;
item.PublishDate = recievedNewsHeadline.PublishDate.ToString();
recievedNewsHeadline.StoryId = recievedNewsHeadline.StoryId;
App.ViewModel.LoadData(item);
};
}, null);
}
private void ToggleSubscribeButton_Click(object sender, RoutedEventArgs e)
{
if (ToggleSubscribeButtonlabel.Text == "Subscribe")
{
_rcpClient = new Rpc.Client(new Uri(RpcUriTextbox.Text));
var userName = UserNameTextbox.Text;
var streamingUri = new Uri(StreamingUriTextbox.Text);
var topic = TopicTextbox.Text;
Log("Creating session...");
_rcpClient.BeginLogIn(userName, PasswordTextbox.Text, loginResult =>
{
try
{
_rcpClient.EndLogIn(loginResult);
_logger.DebugFormat("Session is: {0}", _rcpClient.Session);
Log("Creating streaming client...");
_streamingClient = StreamingClientFactory.CreateStreamingClient(streamingUri, userName, _rcpClient.Session);
_streamingClient.StatusChanged += (s, message)
=> Log(string.Format("Status update: {0}", message.Status));
_streamingClient.Connect();
Log("Creating listener...");
_newsListener = _streamingClient.BuildNewsHeadlinesListener(topic);
Log("Starting listener...");
_newsListener.Start();
Log("Listening to news stream...");
_newsListener.MessageReceived += (s, message) =>
{
try
{
NewsDTO receivedNewsHeadline = message.Data;
Log(
string.Format(
"Received: NewsDTO: StoryId {0}, Headline {1}, PublishDate = {2}",
receivedNewsHeadline.StoryId,
receivedNewsHeadline.Headline,
//receivedNewsHeadline.PublishDate.ToString("u")));
// dates are currently strings
receivedNewsHeadline.PublishDate));
}
catch (Exception exception)
{
_logger.Error("Exception occured:", exception);
}
};
}
catch (Exception exception)
{
_logger.Error("Exception occured:", exception);
}
}, null);
ToggleSubscribeButtonlabel.Text = "Stop";
}
else
{
try
{
Log("Stopping listening to news stream...");
// D: abbreviating conditionals makes it hard to step
// and is also a good way to get bugs. you may notice that I always use
// blocks.
if (_newsListener != null)
{
_newsListener.Stop();
}
Log("Disconnecting from streaming server...");
if (_streamingClient != null)
{
_streamingClient.Disconnect();
}
Log("Deleting session...");
if (_rcpClient != null )
{
// REMOVEME: i commented this out and still getting the ObjectDisposed exception
// so it is not in the RpcClient
_rcpClient.BeginLogOut(logoutResult =>
{
// FIXME: id/session invalid - getting back LoggedOut: false
/*do nothing*/
var breakTarget = 0;
}, null);
}
}
catch (Exception exception)
{
_logger.Error("Exception occured:", exception);
}
ToggleSubscribeButtonlabel.Text = "Subscribe";
}
}
