Book Image

Backbase 4 RIA Development

Book Image

Backbase 4 RIA Development

Overview of this book

Backbase is a very powerful and complex JavaScript library, with many user interface components to help make web development easier. It allows the development of Rich Internet Applications (RIA) that run within all major browsers but its powers and complexity mean that the choice of component can be overwhelming. Understanding when and how to use the right component might not always be straightforward. This book makes that easier. This is a practical book that teaches you how to use the Backbase Client Framework effectively, with a complete overview and many examples. A core developer of the framework puts the technologies used into a wider perspective of existing web standards and a seasoned software architect explains why XML-based UI definition produces better web applications. The transparent use of AJAX technologies, for example to submit forms, or to retrieve updates for data grids, can be taken for granted with the Backbase framework. Packed with examples, the book shows you how to get the most from the library of UI components, and then extend the library with its own custom language. With this book in hand, it is easy to enable AJAX within your web application. You will be able to use the Backbase framework effectively, from basic applications to complex, custom-defined UI components. This book contains a complete overview of all the UI libraries available within the Backbase framework and shows examples for each element described. The Backbase framework offers an innovative Tag Definition Language (TDL), which allows developers to create new UI components that can be used as XML elements, in the same way as using the built-in GUI library. Using TDL brings considerable development advantages, and this book explains how. Significant attention is also given to architectural aspects of designing a web-application, showing sample applications using a model-view-controller approach.
Table of Contents (16 chapters)
Backbase 4 RIA Development
Credits
About the Authors
About the Reviewers
Preface

Asynchronous communication


The first letter "A" in the word AJAX stands for Asynchronous. You may wonder, however, what is asynchronous to what, and how is this possible?

When a page is loaded in the web browser, it starts its client-side life. In that period of time, many interesting things happen in modern web pages or web applications. For example, some animations could start running, some content could be updated, and so on.

True asynchronous processes in the browser do not exist, in any case, not when this book was written. This means that any of execution JavaScript code initiated, for example, by a user input event would have to be processed entirely before another event could happen. The same is true for JavaScript timeouts and intervals—they are not executed in parallel, but rather sequentially.

I/O operations can happen asynchronously though. Once initialized from synchronous JavaScript code, the request can start traveling to a remote server and back. As soon as the server replies...