The next technologies we will look at depart from the server-oriented tools we have used. You have probably heard of AJAX, Asynchronous JavaScript and XML transfer. At the least, you have probably seen it on sites like Google Mail and Yahoo! Mail. AJAX allows web browsers to interact with a server without refreshing the page. Combined with dynamic HTML, it has created a new level of interactivity between users and websites. With the near instantaneous data changes in front of a user, web applications have never been more like desktop applications.
Another benefit to AJAX is that it can severely decrease the traffic between web browser and web server. When we take a look at the amount of data being passed to Google Maps, we will see why constant refreshes would slow down the application too much.
As we discuss AJAX and XMLHttpRequest
, we’ll build a very simple web application. This application will take input from the user, pass it to a server, the server will send back...