Getting Started

Before we are even able to use the Ajax engine that we constructed in the previous chapter, we will have to import all the JavaScript files that are associated with the engine. We currently have created a total of two objects that are necessary for the engine to run, but by the end of this part of the book, we will have a total of four that are necessary because we will be extending the engine with a Utility object and an HTTP object in Chapter 9, "Extending the Engine." To make things easier to remember, the following code will include all four objects that the engine will ultimately need to import in order to run properly. Here is how the four import statements should look in an application's head:

<script type="text/javascript" src="/books/1/87/1/html/2/javascript/Utilities.js"></script> <script type="text/javascript" src="/books/1/87/1/html/2/javascript/model/AjaxUpdater.js"></script> <script type="text/javascript" src="/books/1/87/1/html/2/javascript/model/HTTP.js"></script> <script type="text/javascript" src="/books/1/87/1/html/2/javascript/model/Ajax.js"></script>

As you can see, importing the JavaScript objects is trivial, but it is the first required step in using the engine and therefore noteworthy. After these objects have been imported, we can make requests, access properties, and get the status of specific requests at any time. Let's move forward by learning how to make our first request through the Ajax engine.