Ajax for Web Application Developers

by Kris Hadlock

Overview

Reusable components and patterns for Ajax-driven applications

Ajax is one of the latest and greatest ways to improve users’ online experience and create new and innovative web functionality. By allowing specific parts of a web page to be displayed without refreshing the entire page, Ajax significantly enhances the experience of web applications. It also lets web developers create intuitive and innovative interaction processes.

Ajax for Web Application Developers provides the in-depth working knowledge of Ajax that web developers need to take their web applications to the next level. The book shows how to create an Ajax-driven web application from an object-oriented perspective, and it includes discussion of several useful Ajax design patterns.

This detailed guide covers the creation of connections to a MySQL database with PHP 5 via a custom Ajax engine and shows how to gracefully format the response with CSS, JavaScript, and XHTML while keeping the data tightly secure. It also covers the use of four custom Ajax-enabled components in an application and how to create each of them from scratch.

The final section of the book combines the individual code examples and techniques from earlier chapters of the book into one larger, Ajax-driven application—an internal web mail application that can be used in any user-based application, such as a community-based web application. Readers will learn not only how to create and use their own reusable Ajax components in this application

but also how to connect their components to any future Ajax applications that they might build.

Web Development/Ajax/JavaScript

Product Details

ISBN-13:	9780672329128
Publisher:	Pearson Education
Publication date:	10/30/2006
Series:	Developer's Library
Pages:	288
Product dimensions:	7.00(w) x 9.00(h) x 0.70(d)

About the Author

Kris Hadlock has been a contract web developer and designer since 1996. He is a featured columnist and writer for InformIT and numerous web design magazines. He is also the founder of Studio Sedition, a web application development firm, and is the cofounder of 33Inc, the company responsible for DashboardHQ. He maintains a blog called Designing with Code, which focuses on web application development from a design perspective and often features useful code snippets to help enhance web applications.You can find all of the above and more about Kris on his website at www.krishadlock.com.

Table of Contents

Introduction

An Introduction to the Book Samples

I: Getting Started

1 Introduction to Ajax

The XML DOM

Measuring the Benefits

2 The Request

An In-Depth Look at XMLHttpRequest

A Standard XHR

A Database-Enabled XHR

Sending Data to a Database-Enabled XHR

Creating the Object

Asynchronous Data Transfers

The Ready State

HTTP Status Codes and Headers

3 The Response

XML

Elements

Attributes

CDATA

Parsing XML

JSON

The Syntax

Using JSON

Parsing JSON

4 Rendering the Response with XHTML and CSS

XHTML

CSS

II: Creating and Using the JavaScript Engine

5 Object-Oriented JavaScript

Object-Oriented Approaches

Using the new Operator

Literal Notation

Associative Arrays

JScript.NET

Object Constructors

Instances

Properties

Methods

Prototypes

Instances

Creating Properties

Overriding and Overwriting Properties

Property Protection

Methods

Extending Objects with Prototyped Methods

6 Creating the Engine

Creating a Custom Ajax Wrapper

Making Requests

The Ready State

The Response

Creating an Ajax Updater

Constructing the Object

Updating the Request Object

The Response

7 Using the Engine

Getting Started

Making a Request

Engine Methods and Properties

8 Debugging

The JavaScript onerror Event

responseText

IE Developer Toolbar

Installing the Plug-in

Disabling the Cache

Navigating the DOM

Viewing Class and ID Information

Safari Enhancer

Installing Safari Enhancer

The JavaScript Console

FireBug

Installing FireBug

The Command Line

Logging Messages in the Console

Levels of Logging

Inspecting Elements

Spying on Ajax

9 Extending the Engine

Creating a Utilities Object

Handling Status Codes with an HTTP Object

HTTP Status Code Categories

Using the HTTP Object

III: Creating Reusable Components

10 Accordion

Getting Started

The XML Architecture

Requesting the XML

Creating the Accordion Object

Panel Functionality and Data Display

Creating the CSS

11 Tree View

Structuring the Data

Handling the Response

Rendering the GUI

Adding Style to the Component

12 Client-Side Validation

Getting Started

Creating a Validation Object

Validating User Input

Providing Visual Feedback

The Server Side

The Constructor

Verifying User Information

Registering and Logging In a User

13 Data Grid

Getting Started

Creating a DataGrid Object

Displaying the Data

Creating a DataRow Object

Creating a DataColumn Object

Adding Design to the Component

IV: AJAX Patterns

14 Singleton Pattern

An Overview of the Singleton Pattern

Creating an Object Using the Singleton Pattern

Using the Singleton Object

15 Model View Controller

An Overview of the Pattern

Creating the Pattern

Using the Pattern

16 The Observer Pattern

Pattern Overview

Register Observers Overview

Notify Observers Overview

Unregister Observers Overview

Creating an Error-Handling Object

Register Observers

Notify Observers

Unregister Observers

Using the Error-Handling Object

17 Data Reflection Pattern

An Overview

The Multi-User Pattern

Creating the Pattern

18 Interaction Patterns

Creating a History with Cookies

The Historian Object

Creating and Displaying the XML

The Navigation Object

Drag and Drop

The DragDrop Object

19 Usability Patterns

Handling Feedback, Errors, and Warnings

Designing with Code

V: Server-Side Interaction

20 Understanding Ajax Database Interaction

Connecting with PHP

Bridging the Gap

Making the Requests

Making the Connection

21 Interacting with a Database: The Server-Side

Connecting to ASP.NET

Connecting to ColdFusion

22 Advanced Ajax Database Interaction

Bulk Updates

Sending Arrays

Sending XML

Sending JSON

Server-Side XML and JSON

XML

JSON

VI: Finishing Touches

23 Securing Your Application

Security Holes

Password-Protecting Ajax Requests

Creating Unique Passwords

Verifying Passwords on the Server-Side

24 Best Practices

Using the Engine

Design Patterns

Using Components

Static Versus Dynamic Responses

Error and Feedback Handling

Application History

Security

0672329123, TOC, 9/25/2006

Editorial Reviews

The Barnes & Noble Review
Suddenly, hundreds of enterprises are doing serious work with Ajax. Now, Kris Hadlock has written a web application developer's guide to Ajax that reflects all this experience.

You may have seen Hadlock's cover story on Ajax in .NET magazine. That was just a taste. In this book, he offers a comprehensive Ajax tutorial built around the construction of a full-fledged application from start to finish

You'll start by plumbing the inner workings of the XMLHttpRequest object that's central to the way Ajax works. Hadlock then turns to the response, introducing two specific data-interchange formats in which it can be received: XML and JSON. Part I concludes with a primer on displaying data with CSS and (X)HTML.

Hadlock walks through creating, using, debugging, and extending the Ajax JavaScript engine, then presents an in-depth treatment of creating reusable components. There are four chapter-length case study examples, including tree views, client-side validation, and data grids. The fourth: "Accordion," expands or collapses a web page to show only the data users are interested in. It's a classic example of the "desktop-like" richness Ajax brings to web development.

Next, Hadlock codifies a series of best-practice design patterns for Ajax development. If you're familiar with patterns, some of their names will sound familiar: singleton and observer, for example. There's a full chapter on using Model View Controller with Ajax; as well as chapters on patterns for multi-user applications, interaction, and usability. There's a full section on server-side database interaction -- and, as you might hope, a chapter on security, too. Now that Ajax is no longer a toy, this book will help you build the industrial-strength applications your clients now demand. Bill Camarda, from the December 2006 Read Only