Publish Subscribe

PublishSubscribe allows multiple browser windows to communicate which each other. The windows don't even have to be from the same browser ... for example, a message sent from Internet Explorer can be received from a Firefox browser window. This service is inspired by HTML5's Cross Document Messaging

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>Publish Subscribe</title>
<style type="text/css" media="screen">
#result {
	font-family: "Consolas", "Monaco", "Courier New", Courier, monospace;
	font-size: 8pt; background:#100e0e;	padding:4px; color:#81d83b;
	overflow:auto; height:250px; width:450px; border:4px solid #433;
}

</style>
</head>
<body>
<p>Type a message here, and see it in any and all other browsers visiting<br>
this page (on your local computer).</p>

<input id="msg" type="text" size="60" value="Type your message here">
<div>
    <input id="sendAsString" type="button" value="Send As String">
    <input id="sendAsObject" type="button" value="Send As Object">
    <input id="sendAsArray" type="button" value="Send As Array">
</div>
<br>
<p><strong>Messages Received</strong> (new messages on top):</p>
<pre id="result"></pre>
<p><a target="another" href="publish_subscribe.html">Open a second window</a> to get a 
better idea of what this can do.  If you are<br> really daring, you'll 
<a href="publish_subscribe.html">copy this url</a> and open it in a different browser.</p>
    
<script src="http://bp.yahooapis.com/2.9.9/browserplus-min.js"></script>  
<script src="http://yui.yahooapis.com/combo?2.7.0/build/yahoo-dom-event/yahoo-dom-event.js"></script> 
<script src="/js/json2.js"></script><!-- for pretty output -->
<script type="text/javascript">  
(function() {
    var YD = YAHOO.util.Dom, YE = YAHOO.util.Event, msg = YD.get("msg");

    // function designated to receive messages
    function receiver(val) {
		var r = YD.get("result");
        var str = JSON.stringify(val, null, "  ") + "\n\n" + r.innerHTML;

		if(r.outerHTML) {
    		r.outerHTML = '<pre id="result">'+str+'</pre>';
		} else {
			r.innerHTML = str;
		}
    }

    // PUBLISH
    function publish(e, obj) {
        var data, str = msg.value;
        
        // show that multiple data types can be sent
        if (obj === "string") {
            data = str;
        } else if (obj === "array") {
            data = str.split(" ");
        } else {
            data = {message: str, one: 1, yes: true, no: false};
        }

        BrowserPlus.PublishSubscribe.postMessage({data:data, targetOrigin: "*"}, function(){});
    }

    BrowserPlus.init(function(res) {  
        var services = {service: "PublishSubscribe", version: "1"};
            
        if (res.success) {  
            BrowserPlus.require({ services: [ services ]}, function(r) {
                if (r.success) {  
                    // SUBSCRIBE
                    BrowserPlus.PublishSubscribe.addListener({receiver: receiver}, function() {});
                } else {
                    alert("Require Failed: " + r.error + ", " + r.verboseError);
                }
            });
        } else {
            alert("Init Failed: " + res.error + ", " + res.verboseError);            
        }
    });
    
    YE.addListener("sendAsString", "click", publish, "string");
    YE.addListener("sendAsObject", "click", publish, "object");
    YE.addListener("sendAsArray",  "click", publish, "array");
})();
</script>
</body>
</html>
Run Example

Make sure to run this code in a second (and even third) window to see the messages sent back and forth. While you're at it, you can even come back to the code demo in a different browser.

NOTE
No IFRAMEs were hurt in the making of this demo.