Ajax Design Patterns

Ajax, or Asynchronous JavaScript and XML, exploded onto the scene in the spring of 2005 and remains the hottest story among web developers. With its rich combination of technologies, Ajax provides a strong foundation for creating interactive web applications with XML or JSON-based web services by using JavaScript in the browser to process the web server response.

Ajax Design Patterns shows you best practices that can dramatically improve your web development projects. It investigates how others have successfully dealt with conflicting design principles in the past and then relays that information directly to you.

The patterns outlined in the book fall into four categories:

• Foundational technology: Examines the raw technologies required for Ajax development
• Programming: Exposes techniques that developers have discovered to ensure their Ajax applications are maintainable
• Functionality and usability: Describes the types of user interfaces you'll come across in Ajax applications, as well as the new types of functionality that Ajax makes possible
• Development: Explains the process being used to monitor, debug, and test Ajax applications

Ajax Design Patterns will also get you up to speed with core Ajax technologies, such as XMLHttpRequest, the DOM, and JSON. Technical discussions are followed by code examples so you can see for yourself just what is-and isn't-possible with Ajax. This handy reference will help you to produce high-quality Ajax architectures, streamline web application performance, and improve the user experience.

Michael Mahemoff holds a PhD in Computer Science and Software Engineering from the University of Melbourne, where his thesis was "Design Reuse in Software Engineering and Human-Computer Interaction." He lives in London and consults on software development issues in banking, health care, and logistics.

"Michael Mahemoff's Ajax Design Patterns is a truly comprehensive compendium of web application design expertise, centred around but not limited to Ajax techniques. Polished nuggets of design wisdom are supported by tutorials and real-world code examples resulting in a book that serves not only as an intermediate to expert handbook but also as an extensive reference for building rich interactive web applications."

--Brent Ashley, remote scripting pioneer

The CPU meter shows the problem. One core is running at 100 percent, but all the other cores are idle. Your application is CPU-bound, but you are using only a fraction of the computing power of your multicore system. What next?

The answer, in a nutshell, is parallel programming. Where you once would have written the kind of sequential code that is familiar to all programmers, you now find that this no longer meets your performance goals. To use your systems CPU resources efficiently, you need to split your application into pieces that can run at the same time. This is easier said than done. Parallel programming has a reputation for being the domain of experts and a minefield of subtle, hard-to-reproduce software defects.

Everyone seems to have a favorite story about a parallel program that did not behave as expected because of a mysterious bug. These stories should inspire a healthy respect for the difficulty of the problems you face in writing your own parallel programs. Fortunately, help has arrived. Microsoft Visual Studio® 2010 introduces a new programming model for parallelism that significantly simplifies the job. Behind the scenes are supporting libraries with sophisticated algorithms that dynamically distribute computations on multicore architectures. Proven design patterns are another source of help. A Guide to Parallel Programming introduces you to the most important and frequently used patterns of parallel programming and gives executable code samples for them, using the Task Parallel Library (TPL) and Parallel LINQ (PLINQ).

Michael Mahemoff holds a Ph.D in Computer Science and Software Engineering from The University of Melbourne, where his thesis was on "Design Reuse in Software Engineering and Human-Computer Interaction". He lives in London and consults on software development issues in banking, healthcare, and logistics.

• Chapter 1: Introducing Ajax
• Chapter 2: A Pattern-Led Tutorial
• Chapter 3: Ajax Design: Principles and Patterns

• Chapter 4: Ajax App
• Chapter 5: Display Manipulation
• Chapter 6: Web Remoting
• Chapter 7: Dynamic Behavior
• Chapter 8: Extended Technologies

• Chapter 9: Web Services
• Chapter 10: Browser-Server Dialogue
• Chapter 11: DOM Population
• Chapter 12: Code Generation and Reuse
• Chapter 13: Performance Optimization

• Chapter 14: Widgets
• Chapter 15: Page Architecture
• Chapter 16: Visual Effects
• Chapter 17: Functionality

• Chapter 18: Diagnosis
• Chapter 19: Testing

• Ajax Frameworks and Libraries
• Setting Up the Code Examples
• Patterns and Pattern Languages
• References