Node.js Training And Node.js Hosting With Nodejitsu

// Include the necessary modules.
var sys = require( "sys" );
var http = require( "http" );
var fs = require( "fs" );

// This is the static file server module for our site.
var static = require( "node-static" );


// ---------------------------------------------------------- //
// ---------------------------------------------------------- //


// Load the Tumblr RSS proxy. When that is done, we have everything
// that we need to start running the server.
//
// NOTE: The RSS feed might not be available right away (requires an
// ansynchronous HTTP request); however, as this happens only at the
// beginning of the application, I don't feel a need to use the
// available callback.
var tumblr = require( "./lib/tumblr" ).load(
	function(){

		// Log that the data has loaded.
		sys.puts( "Tumblr RSS data has loaded." );

	}
);


// Read in the output template. This site is only going to serve up
// this one page. Since this will only be read in once, just read it
// in SYNChronously - this way we can get the file contents back
// immediately and don't have to use a callback.
var htmlTemplate = fs.readFileSync(
	(__dirname + "/views/index.htm"),
	"utf8"
);


// Create our static file server. We can use this to facilitate the
// serving of static assets with proper mime-types and caching.
var staticFileServer = new static.Server( "." );


// Create an instance of the HTTP server. While we are using a static
// file server, we will need at HTTP server to handle the one dynamic
// page (the homepage) and to hand requests off to the static file
// server when necessary.
var server = http.createServer(
	function( request, response ){

		// Parse the requested URL.
		var url = require( "url" ).parse( request.url );

		// Get requested script.
		var scriptName = url.pathname;

		// Check to see if the homepage was requested. If so, then we
		// need to load it and serve it. If not, then we can just
		// pass the request off to the static file server (which will
		// handle any necessary 404 responses for us).
		if (scriptName.search( /^\/(index\.htm)?$/i ) == 0){

			// Get the next RSS feed item (might return NULL).
			var rssItem = tumblr.next();

			// Set the 200-OK header.
			response.writeHead(
				200,
				{ "Content-Type": "text/html" }
			);

			// Write the index page to the response and then
			// close the output stream.
			response.end(
				htmlTemplate.replace(
					new RegExp( "\\$\\{rssItem\\}", "" ),
					(rssItem || "Oops - No data found.")
				)
			);

		} else {

			// If this isn't the index file, pass the control
			// off to the static file server.
	staticFileServer.serve( request, response );

		}

	}
);

// Point the server to listen to the given port for incoming
// requests.
server.listen( 8080 );


// ---------------------------------------------------------- //
// ---------------------------------------------------------- //


// Output fully loaded message.
sys.puts( "Server is running on 8080." );

// Include the necessary modules.
var http = require( "http" );


// ---------------------------------------------------------- //
// ---------------------------------------------------------- //


// Define the Tumblr RSS URL that we are going to be feeding into
// this site.
var tumblrRSS = "http://bennadel.tumblr.com/rss";

// I am the locally cached RSS items.
var rssItems = [];

// I am the current index of the RSS items (each request will move
// this index forward one index).
var rssIndex = 0;


// ---------------------------------------------------------- //
// ---------------------------------------------------------- //


// I am a place-holder function that does nothing more than provide
// an invocation API (can be used to simplify callback logic).
function noop(){
	// Left intentionally blank.
}


// I am a helper function that simplifies the HTTP request,
// encapsulating the concatenation of response data packets into
// a single callback.
function httpGet( httpOptions, callback ){

	// Make the request with the given options.
	var request = http.request( httpOptions );

	// Flush the request (we aren't posting anything to the body).
	request.end();

	// Bind to the response event of the outgoing request - this will
	// only fire once when the response is first detected.
	request.on(
		"response",
		function( response ){

			// Now that we have a response, create a buffer for our
			// data response - we will use this to aggregate our
			// individual data chunks.
			var fullData = [ "" ];

			// Bind to the data event so we can gather the response
			// chunks that come back.
			response.on(
				"data",
				function( chunk ){

					// Add this to our chunk buffer.
					fullData.push( chunk );

				}
			);

			// When the response has finished coming back, we can
			// flatten our data buffer and pass the response off
			// to our callback.
			response.on(
				"end",
				function(){

					// Compile our data and pass it off.
					callback( fullData.join( "" ) );

				}
			);

		}
	);

}


// I load the RSS feed from TUMBLR using Yahoo! Query Language (YQL).
// When the RSS feed has been pulled down (as JSON), it is passed
// off to the callback.
function getRSS( callback ){

	// Define the YQL query. Since this is going to become a URL
	// component itself, be sure to escape all the sepcial
	// characters.
	var yqlQuery = encodeURIComponent(
		"SELECT * FROM xml WHERE url = '" +
		tumblrRSS +
		"'"
	);

	// Make the request and pass the callback off as the callback
	// we are going to use with the RSS HTTP request.
	httpGet(
		{
			method: "get",
			host: "query.yahooapis.com",
			path: ("/v1/public/yql?q=" + yqlQuery + "&format=json"),
			port: 80
		},
		callback
	);

}


// I load the remote RSS feed locally.
function loadRSS( callback ){

	// Get the remote Tumblr RSS data. When it had been loaded,
	// store it locally.
	getRSS(
		function( rssData ){

			// Deserialize the RSS JSON.
			var rss = JSON.parse( rssData );

			// Make sure that there are RSS items.
			if (
				rss.query.results.rss.channel.item &&
				rss.query.results.rss.channel.item.length
				){

				// Copy the RSS items reference to the local
				// collection.
				rssItems = rss.query.results.rss.channel.item;

			}

			// Whether or not we received any valid RSS items, we've
			// done as much as we can at this point. Invoke the
			// callback.
			(callback || noop)();

		}
	);

}


// ---------------------------------------------------------- //
// ---------------------------------------------------------- //


// I get the next item in the RSS collection (or return null).
function getNextItem(){

	// Check to make sure that we have at least one RSS item. If
	// not, then return null.
	if (!rssItems.length){
		return;
	}

	// Increment the index - each request further traverses the
	// RSS feed.
	rssIndex++;

	// Check the index bounds - if we've gone too far, simply loop
	// back around to zero.
	if (rssIndex >= rssItems.length){

		// Loop back around.
		rssIndex = 0;

	}

	// Return the description of the current item.
	return( rssItems[ rssIndex ].description );

}


// ---------------------------------------------------------- //
// ---------------------------------------------------------- //


// I initialize the component and return an API for data interaction.
exports.load = function( callback ){

	// Create a simple API for our Tumblr service.
	var localAPI = {
		next: getNextItem
	};

	// Load the RSS feed (grabs the remote RSS data and caches it
	// locally for serving. Once it has loaded, pass off the local
	// API to the callback. This way, the calling context can use
	// either the RETURN value or the CALLBACK value.
	loadRSS(
		function(){
			(callback || noop)( localAPI );
		}
	);

	// Set up an interval to check for a new RSS feed every hour.
	// This will completely replace the locally cached data.
	setInterval(
		loadRSS,
		(1 * 60 * 60 * 1000)
	);

	// Return a simple interface to our Tumblr object.
	return( localAPI );

};

{
	"name": "gymspiration",
	"subdomain": "gymspiration",
	"description": "Pictures of athletic women that will make you feel like you need to go workout ASAP!",
	"version": "0.5.0-1",
	"author": "Ben Nadel <ben@bennadel.com> (http://www.bennadel.com)",
	"main": "./server.js",
	"scripts": {
		"start": "server.js"
	},
	"engines": {
		"node": "0.4.6"
	},
	"dependencies": {
		"node-static": "0.5.4"
	}
}