Developing AJAX Web applications using Dojo and DB2

Follow this case analysis, using ibm®db2®9 for linux®, UNIX®, and Windows®, XQuery, PHP, and the Dojo JavaScript Framework to quickly create an elegant, responsive Web application. This case study is based on IOD Planner 2006, a WEB application for the IBM information on Demand 2006 Global Conference. Learn the benefits of the AJAX approach and learn how to implement this application incrementally.

Before you start

About this tutorial

The purpose of this tutorial is two-demonstrating the benefits of using the Ajax/web 2.0 approach for WEB development and demonstrating the power of DB2 9 purexml™. Based on these two purposes, I wrote the information on Demand 2006 Scheduler application in conjunction with information on Demand 2006 Global Conference. This is a simple application that you can use to plan your meeting schedule. It utilizes the ajax--asynchronous JavaScript and xml--method for WEB programming, enabling intuitive and simple user interaction. It also leverages the fast PureXML capabilities of IBM DB2 9.

Figure 1 illustrates the development of the IOD Planner application. All the loads in the background are loaded to avoid the refresh delay, and rich parts are used for form fields, dialog boxes, and Drop-down menus.

Figure 1. IOD Planner 2006

Prerequisite

You should have a proper understanding of Web development and databases. The tutorial "DB2 XML Evaluation Guide" (developerworks,2006 year June) is a good introduction to DB2 9, while "Query DB2 XML Data with XQuery" (DeveloperWorks , April 2006) introduces XQuery.

System Requirements

To deploy the source code, you need a Windows or Linux operating system. On it, you need to install Zend Core for IBM (see Resources for the download link). Zend Core is conveniently bundled with the DB2 9 express-c data Server, Apache2 Web Server, PHP scripting language, DB2 PHP extensions, and a powerful management console.

Why use Ajax?

Figure 2. Traditional WEB models and Ajax models

The key principle of Ajax fundamentals is to avoid loading new WEB pages. Instead, you can load the new content in the background and display it in an existing page. This avoids the waste of reloading the basic framework and does not take time to wait for browsers to render the same navigation and design. Your users will not see empty pages in the load. The end result is a quick, responsive application.

Use the XMLHttpRequest object to send a request to the server and asynchronously process it when the response arrives. In contrast to its name, the object is not limited to XML. Any blank text format, from JavaScript (JSON) to CSV to pre-generated HTML, can be received using this mechanism. We select the latter-the HTML generated in the server.

Ajax-style WEB applications mainly include Bloglines, Del.icio.us, Digg, Flickr, Google Map, Gmail and Reddit.