Presentation

server.js

@@ -0,0 +1,117 @@
+/**
+ *    server.js
+ *
+ *    An example of a Node.js server that streams a set
+ *    of events to a browser. This is primarily aimed at
+ *    use with wii-js; since the wii's browser has a set of
+ *    quirks like no other, this file can be expected to change.
+ *
+ *    This is commented possibly more liberally than it should be,
+ *    as it's intended to be easily accessible by those who might not
+ *    have worked with Node.js and/or Server Sent Events before.
+ *
+ *    @Author: Ryan McGrath <ryan@venodesigns.net>
+ *    @Requires: Nothing, sans a little Node.js
+ */
+var DEBUG = true,
+    PORT = 8080,
+    http = require('http'),
+    util = require('util'),
+	fs = require('fs');
+
+/**
+ *  sendEvent()
+ *
+ *  Sends down a set of events roughly every ~5 seconds. Not that
+ *  many would go so low, but sending more than once every ~500ms is
+ *  not recommended. The Wii's browser has some odd memory limitations
+ *  that aren't too much fun to be caught up in.
+ *
+ *	@response - response object/stream, where data gets written to.
+ */
+var sendEvents = function sendEvent(response) {
+    var id = (new Date()).toLocaleTimeString(),
+        data = (Math.floor(Math.random() * 10000) + 2);
+
+    response.write('id: ' + id + '\n');
+    response.write('data: ' + data + '\n');
+
+    /**
+     *    Set this up to re-send in a few seconds on the
+     *    same request.
+     */
+    setTimeout(function() {
+        sendEvents(response);
+    }, 5000);
+};
+
+/**
+ *	determineContentType(url)
+ *
+ *	Given a url, determines one of three content types that we care
+ *	about. I'm an opinionated person and chose not to use Express here,
+ *	but if you'd rather not deal with it the static module there is quite
+ *	possibly your new best friend.
+ *
+ *	@url - string, url to be tested for content-type
+ */
+var determineContentType = function determineContentType(url) {
+	if(/\.js/.test(url)) return 'text/javascript';
+	if(/\.css/.test(url)) return 'text/css';
+	return 'text/html';
+};
+
+/**
+ *	Now we'll set up a simple server that listens our our port we set
+ *	above, which will either distribute resources or events depending
+ *	on the headers.
+ */
+http.createServer(function(request, response) {
+	/**
+	 *	All but useless to us...
+	 */
+	if(request.url === '/favicon.ico') {
+		response.writeHead(404);
+		response.end();
+		return;
+	}
+
+    /**
+     *    If things don't appear to be working, uncomment this and check out
+     *    what's getting posted over. Certain headers need to be set by the browser;
+     *    it's possible they're not getting set for some reason...
+     */
+    if(DEBUG && request.url !== '/favicon.ico') {
+        util.puts('\n-----------------------------------------------------');
+        util.puts('URL: ' + request.url);
+        for(var key in request.headers) {
+            util.puts(key + ': ' + request.headers[key]);
+        }
+    }
+
+    /**
+     *    See the comment about DEBUG/headers above. If we have proper headers, we'll
+     *    start sending down a stream of events; if not, we'll assume it's a normal request
+     *    and serve up some HTML/CSS/JS/etc.
+     */
+    if(request.headers.accept && request.headers.accept === 'text/event-stream') {
+        response.writeHead(200, {
+            'Content-Type': 'text/event-stream',
+            'Cache-Control': 'no-cache',
+            'Connection': 'keep-alive'
+        });
+        sendEvents(response);
+    } else {
+        var file = request.url === '/' ? '/presentation.html' : request.url;
+
+		response.writeHead(200, {'Content-Type': determineContentType(request.url)});
+        fs.readFile(__dirname + file, 'utf-8', function(err, data) {
+			if(err) throw err;
+			response.write(data);
+			response.end();
+		});
+    }
+}).listen(PORT);
+
+util.puts('\n--------------------------------------------------------------------');
+util.puts('Server started and listening on port ' + PORT + '.');