MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

}
try {
var size = dataWriter.measureString(data);
countOfDataSent += size;
}
dataWriter.writeString(data);
dataWriter.storeAsync().done(function () {
// Add a 1 second delay so the user can see what's going on.
setTimeout(writeOutgoing, 1000);
}, writeError);
}
catch (error) {
// [Output error message]
}
function readIncoming(args) {
// Buffer as much data as you require for your protocol.
dataReader.loadAsync(100).done(function (sizeBytesRead) {
countOfDataReceived += sizeBytesRead;
// [Output count]
var incomingBytes = new Array(sizeBytesRead);
dataReader.readBytes(incomingBytes);
// Do something with the data. Alternatively you can use DataReader to
// read out individual booleans, ints, strings, etc.
}
// Start another read.
readIncoming();
}, readError);
function onClosed(args) {
// [Other code omitted, including closure of DataReader and DataWriter]
streamWebSocket.close();
}
As with regular sockets, you can exercise additional controls with WebSockets, including setting
credentials and indicating supported protocols through the control property of both MessageWeb-Socket
and StreamWebSocket. For details, see How to use advanced WebSocket controls in the documentation.
Similarly, you can set up a secure/encrypted connection by using the wss:// URI scheme instead of
ws:// as used in the sample. For more, see How to secure WebSocket connections with TLS/SSL.
The ControlChannelTrigger Background Task
In Chapter 13, in the “Lock Screen Dependent Tasks and Triggers” section we took a brief look at the
Windows.Networking.Sockets.ControlChannelTrigger class that can be used to set up a background
task for real-time notifications as would be used by VoIP, IM, email, and other “always reachable”
scenarios. To repeat, working with the control channel is not something that can be done
from JavaScript, so refer to How to set background connectivity options in the documentation along
with the following C#/C++ samples:
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