Modern JavaScript: Develop and Design

11. Ajax

As suggested in Chapter 1, (Re-)Introducing JavaScript, Ajax is one of the most important developments in the history of both JavaScript and Web development. Simply put, Ajax is the process of having JavaScript in the browser make a behind-the-scenes request of the server, in order to retrieve additional information or cause a server-side reaction. For example, the request may retrieve a set of data to be displayed, see if a username is available, or update a record in the database. While this is happening, the user could be unaware of the transaction, still using the page that was originally loaded. Grasping the concept, and benefits, of Ajax can sometimes be hard, and Ajax creates additional debugging challenges, but mastering Ajax ...