Bulletproof Ajax with ASP.NET MVC

Posted by andy gaskell on Aug 2nd, 2008

After reading the excellent Bulletproof Ajax by Jeremy Keith, I thought porting the Bulletproof Books sample application to ASP.NET MVC would be a great first attempt at building an ASP.NET MVC application. One of the main points of Bulletproof Ajax is that Ajax should be used to enhance usability and not to make Ajax a requirement to access your content. My version of the Bulletproof Books Shop also makes Javascript and XMLHttpRequest support optional.

Keeping the site accessible to most web browsers took some extra work and consideration when building the Controllers. I decided that any HomeController actions would render html for the entire page.

   13         public ActionResult Index()

   14         {

   15             ViewData.Model = Product.Products;

   16             return View(“Index”);

   17         }

   18 

   19         public ActionResult AddProductToCart(string productID, int quantity)

   20         {

   21             CartController cartController = new CartController();

   22             cartController.AddProduct(productID, quantity);

   23             return Index();

   24         }

   25 

   26         public ActionResult RateProduct(string productID, string rating)

   27         {

   28             RatingController ratingController = new RatingController();

   29             ratingController.RateProduct(productID, rating);

   30             return Index();

   31         }

Controllers that refresh partial chunks of html will know how to respond to actions (add product to cart, rate a product) and render views mapped to MVC user controls. The client will make http requests to different urls based on javascript support in the browser. For example to add a product to a cart with javascript enabled, the javascript will make a post to /Cart.mvc/AddProduct and the server will response with a chunk of html. To add a product with javascript disabled the client will post to /Home.mvc/AddProductToCart and the server will respond with an entire page. The HomeController ends up forwarding the call to the appropriate controller so we’re able to avoid duplicating logic.

   28         public ActionResult DisplayCart()

   29         {

   30             Cart cart = GetCart();

   31             return View(“Cart”, cart);

   32         }

   33 

   34         public ActionResult AddProduct(string productID, int quantity)

   35         {

   36             Cart cart = GetCart();

   37             Product product = Product.Products.Find(s => s.ID == productID);

   38             cart.AddProduct(product, quantity);

   39             SetCart(cart);

   40             return View(“Cart”, cart);

   41         }

One thing I’m not sure about is state management in ASP.NET MVC, so I’m currently storing the cart and ratings in session.

   22         private Rating GetRatings()

   23         {

   24             Rating rating = System.Web.HttpContext.Current.Session["Rating"] as Rating;

   25             if (rating == null)

   26             {

   27                 rating = new Rating();

   28             }

   29             return rating;

   30         }

   31 

   32         private void SetRating(Rating rating)

   33         {

   34             System.Web.HttpContext.Current.Session["Rating"] = rating;

   35         }

You can download the source here.

Getting access to MSDN downloads with the Empower ISV program

Posted by andy gaskell on Jul 12th, 2008

Ok, so like 99% of my blog entries are about things not working quite the way I think they should and here’s another example. When linking your Passport account to your MSDN Subscription you’re asked to provide your Benefit Access Number. The number they’re looking for is your Technical ID available on Microsoft Parter Program site. Under Requirements & Assets click Assign Contact Roles.

This method didn’t work for me on the day I received my MSDN shipment - I had to wait a couple days for it to work.

Installing pymedia on Ubuntu

Posted by andy gaskell on Jul 9th, 2008

I’ve been trying to install pymedia on a clean install of Ubuntu Hardy Heron and I was wasn’t able to get it to build using the official docs. Fortunately I found a couple of great blog posts. I ended up having to make a couple of changes:

To install the dependencies I used:

sudo apt-get install python-dev libogg-dev libvorbis-dev liblame-dev libfaad-dev libasound2-dev python-pygame

I had to go to /usr/bin and run this as Michael suggests:

ln -s g++-3.4 g++