CrossBrowdy - Examples



This is an example managing WebSockets (internally, it uses the SockJS client library):


<!DOCTYPE html>
		<meta http-equiv="content-type" content="text/html; charset=utf-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no" />
		<title>Networking: WebSockets - Example</title>
		<!-- Loads the needed CSS files: -->
		<link rel="stylesheet" type="text/css" href="main.css" />
		<!-- Loads CrossBrowdy.js (main file): -->
		<script src="CrossBrowdy/CrossBrowdy.js" type="text/javascript" language="javascript"></script><!-- "type" and "language" parameters for legacy clients. -->
		<!-- Loads the other needed script files: -->
		<script src="main.js" type="text/javascript" language="javascript"></script>
		Penultimate event: <span id="penultimate_event"></span><br />
		Last event: <span id="last_event"></span><br />
		Server: <input type="text" id="server" size="60" value="http://WebSockets_server_URL:port/example" /> <button onClick="start();">Start connection</button><br />
		<br />
		<button onClick="stop();">Close connection</button><br />
		<br />
		<input type="text" id="message" size="60" value="Hello, SockJS server!" /> <button onClick="send();">Send</button>
		<br />
		<!-- The "CB_console" element will be used automatically in the case that the client does not support console: -->
		<div id="CB_console" style="visibility:hidden; overflow:scroll;">
			<span style="font-weight:bold;">Console:</span><br />
		<div id="crossbrowdy_info"><a href="/guides#examples" target="_blank"></a> example</div>


body { background-color:#aaddee; word-wrap:break-word; }
#crossbrowdy_info { position:fixed; bottom:2px; right:2px; }
#crossbrowdy_info a { color:#00aadd; }
#crossbrowdy_info a:hover { color:#0033aa; }
span { color:#aa0000; }
button { color:#006600; }
button:hover { color:#660000; cursor:pointer; }


CB_init(main); //It will call the "main" function when ready.

//This function will be called when CrossBrowdy is ready:
function main()

//Starts a WebSockets connection:
var websocket = null;
function start()
	//Tries to starts a connection to the WebSockets (SockJS) server:
	showEventsInformation("Trying to open the connection...");
	websocket = CB_Net.Sockets.SockJS.listen
		//Defines the server address:"server").value,

		//Defines the handler for the "onOpen" event (optional):
		function webSocketsOnOpen(evt)
			showEventsInformation("The 'onOpen' event was fired! websocket.transport=" + websocket.transport);

		//Defines the handler for the "onClose" event (optional):
		function webSocketsOnClose(evt)
			showEventsInformation("The 'onClose' event was fired! Reason: " + evt.reason);
			websocket = null;

		//Defines the handler for the "onMessage" event (optional):
		function webSocketsOnMessage(evt)
			showEventsInformation("The 'onMessage' event was fired! Data received: " +;

		//Defines the handler for the "onError" event (optional):
		function webSocketsOnError(evt)
			showEventsInformation("The 'onError' event was fired! evt = " + JSON.stringify(evt));

		//Other parameters (internal usage recommended):
		undefined, //options
		undefined //protocols

//Sends a message through the WebSockets connection:
function send()
	//Tries to send a message to the server (if 'websocket' is not provided, it will use the last one created (stored in 'CB_Net.Sockets.SockJS.websocketLast'):
	showEventsInformation("Trying to send the message...");
		//Message to send:"message").value,

		//WebSockets object to use (optional):
		websocket, //If not provided, it will use the last one created (stored in 'CB_Net.Sockets.SockJS.websocketLast').

		//Defines a handler for the "onError" event (optional):
		function(evt) { showEventsInformation("Failed to send the message! evt = " + JSON.stringify(evt)); } //Prints the event object.

//Stops the WebSockets connection:
function stop()
	//Tries to close the connection:
	showEventsInformation("Trying to close the connection...");
		//WebSockets object to use (optional):
		websocket, //If not provided, it will use the last one created (stored in 'CB_Net.Sockets.SockJS.websocketLast').

		//Defines a handler for the "onError" event (optional):
		function(evt) { showEventsInformation("Failed to close the connection! evt = " + JSON.stringify(evt)); } //Prints the event object.

//Shows events information:
function showEventsInformation(message)
	//Updates events information:
	CB_Elements.insertContentById("last_event", message);
For testing this example, you can easily get an open-source and free SockJS server here: SockJS test server on NW.js.

Try this example

You can check the Guides & Tutorials category as well as the API documentation in the case you need more information.

Go back to Guides & Tutorials

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CrossBrowdy by Joan Alba Maldonado