While attending the developer conference Øredev last week, I had the pleasure of giving a talk on es6. Many of the new features I covered touch on challenges we've faced building the Azure Portal. Instead of covering each new feature one by one (Luke Hoban already does a nice job of that) I decided to cover a few high level features that fundamentally affect the way teams build large scale JavaScript applications.
Building asynchronous real time apps with bidirectional communication has traditionally been a very difficult thing to do. HTTP was originally designed to speak in terms of requests and responses, long before concepts of rich media, social integration, and real time communication were considered staples of modern web development. Over the years, various solutions have been hacked together to solve this problem. You can use plugins like flash or silverlight to make a true socket connection on your behalf - but not all clients support plugins. You can use long polling to manage multiple connections via HTTP - but this can be tricky to implement, and can eat up system resources. The Web Socket standard promises to give web developers a first class socket connection, but browser support is spotty and inconsistent.
Various tools across multiple stacks have been release to solve this problem, but in this post I would like to talk about the first real asynchronous client/server package for ASP.NET: SignalR. SignalR allows .NET developers to change the way we think about client/server messaging: instead of worrying about implementation details of web sockets, we can focus on the way communication flows across the various components of our applications.
Over this holiday break I had the interesting opportunity to write a bookmarklet for a friend who runs a comic based website. Instead of just manipulating the currently loaded page, the bookmarklet needed to send a list of images to another site. Often when writing bookmarklets, we tend to only think of loading our code in the context of a HTML content page. How often do you test your bookmarklets when the browser is viewing an image? In this article I am going to go through the code I used to bootstrap my bookmarklet script, and discuss some of the interesting challenges I experienced along the way.
To get started with this code, I used a fantastic article by Tommy Saylor of Smashing Magazine. It gave me a good start, but certainly left a lot of details out, and in my case, caused a lot of bugs.