Book Image

Microsoft AJAX Library Essentials: Client-side ASP.NET AJAX 1.0 Explained

Book Image

Microsoft AJAX Library Essentials: Client-side ASP.NET AJAX 1.0 Explained

Overview of this book

Microsoft AJAX Library Essentials is a practical reference for the client-side library of the ASP.NET AJAX Framework 1.0, and a tutorial for the underlying technologies and techniques required to use the library at its full potential. The main goal of this book is to get you comfortable with the Microsoft AJAX Library, a huge set of functions that can be used for developing powerful client-side functionality.Beginning with a hands-on tour of the basic technologies associated with AJAX, JavaScript, XMLHttpRequest, JSON, and the DOM, you'll move on to a crash course in the Microsoft AJAX tools. You will learn, through numerous step-by-step exercises, how to create basic AJAX applications, how the object-based programming model of JavaScript works, and how Microsoft AJAX Library extends this model. You'll understand the architecture of the Microsoft AJAX components, how they all fit together, and exactly what they can do for you. Then you will learn how to use the Microsoft AJAX Library in your web projects, and a detailed case study will walk you through creating your own customized client components. At every stage of your journey, you'll be able to try out examples to illuminate the theory, and consolidate your understanding. In addition to learning about the client and server controls, you'll also see how to handle errors and debug your AJAX applications.To complement your new found skills, the book ends with a visual reference of the Microsoft AJAX Library namespaces and classes, including diagrams and quick explanations for all the classes mentioned in the book, providing an invaluable reference you will turn to again and again.
Table of Contents (14 chapters)
Copyright
Credits
About the Authors
About the Reviewers
Preface

The XMLHttpRequest Object


XMLHttpRequest is the object that enables the JavaScript code to make asynchronous HTTP server requests. This allows you to initiate HTTP requests and receive responses from the server in the background, without requiring the user to submit the page to the server. This feature, combined with the possibility to manipulate the web page using DOM and CSS, allows you to implement responsive functionality and visual effects backed with live data from the server, without the user experiencing any visual interruptions.

The XMLHttpRequest object was initially implemented by Microsoft in 1999 as an ActiveX object in Internet Explorer, and eventually became de facto standard for all the browsers, being supported as a native object by all modern web browsers except Internet Explorer 6.

Note

Note that even if XMLHttpRequest has become a de facto standard in the web browsers, it is not yet a W3C standard. Similar functionality is proposed by the W3C DOM Level 3 Load and Save...