Bulletproof Ajax

"Bulletproof Ajax" is an indispensable resource for any front-end web designer, developer, or interaction designer who is involved or is planning on being involved in a project that includes Ajax techniques. Whether working on an in-house team or as an independent consultant, you'll need to understand the pros and cons of using this popular and somewhat controversial method of serving web pages. This is not a book for web designers who don't want to code. In order to benefit from this book, you'll need a strong understanding of semantic XHTML and CSS. A passing familiarity with JavaScript is a definite plus as well. (Keith's previous book, DOM Scripting: Web Design with JavaScript and the Document Object Model, is a good place to start.) Chapter 2 begins with an excellent overview of JavaScript terms and functions--the best I've read. (Until you become familiar with JavaScript statements, variables, data types, etc., you'll no doubt be referring back to this chapter often!) I found that "Bulletproof Ajax's" greatest strength is presenting ways to evaluate why and how a project should or shouldn't include Ajax: 1. Is Ajax appropriate for the project? 2. If yes, how will we most effectively implement Ajax? 3. How will we provide for site visitors who don't have JavaScript enabled on their browsers? 4. How will we address accessibility issues? In Chapter 5, Keith elaborates on a technique he calls Hijax (which he introduced in DOM Scripting: Web Design with JavaScript and the Document Object Model). This technique applies two key concepts of modern web design: progressive enhancement and graceful degradation. Although Hijax isn't the answer to all Ajax issues, the idea goes a long way towards ensuring that your carefully crafted Ajax goodness doesn't alienate and/or exclude non-JavaScript site visitors. Simply put, "Bulletproof Ajax" will allow YOU (the front-end guys and gals) to communicate with THEM (the back-end guys and gals) about Ajax and its implementation. This book can help you and your team clarify expectations about Ajax, implement user-centered solutions, and, in all likelihood, save you time and money too.

The trouble with most JavaScript and Ajax related books is they make certain assumptions about the reader, namely that he or she is coming from a server-side programming background. They often say things like: "For those of you who have coded in Python..." or "Perl style regular expressions..." This is good if indeed you are familiar with Python or Perl, etc. But what about the rest of us? Thankfully, Jeremy Keith has stepped up to fill the void with Bulletproof Ajax. This book does not presuppose a heavy programming background. Instead, it is geared towards the web designer who wants to become more of a front-end developer. The prerequisites are: understanding of semantics, HTML and CSS. If that's you - good news! You already have a working knowledge of the Document Object Model, an essential piece of the Ajax puzzle. Who better to explain it, than co-lead of the DOM Scripting Task Force himself. This book begins by laying the groundwork for an intelligible conversation. It defines JavaScript syntax such as: functions, methods, arrays and objects. With that vocabulary in place, it jumps into manipulating XHTML documents with JavaScript. It then explains unobtrusive concepts, and gets into the XMLHttpRequest and the world of possibilities that come with it. This book is unique in that it actually acknowledges the drawbacks of Ajax and, like it's namesake Bulletproof Web Design, helps you plan for contingencies. Rather than referring to accessibility as something that must be added in later, he advocates not removing it in the first place. After all, HTML is already accessible. It's things we do to it with CSS and JavaScript that taint it. On page 102, he urges developers to: 1. Plan for Ajax from the start. 2. Implement Ajax at the end. He also warns against using JavaScript alone to handle things like form validation and complex calculations. If you rely on this only, you have no fall-back plan. Ideally, JavaScript should be like a waiter going to a from a kitchen, serving things to the end-user. Let me share a few more quotes. Page 99: "Far too many Ajax applications are built on the assumption that JavaScript will be available. Instead of treating the language as a tool for enhancing functionality, these applications make JavaScript a requirement. Core functionality is carried out with JavaScript, resulting in an all-or-nothing situation for the user." Page 116: "Just because you've hired a waiter doesn't mean you can fire the cook. Yet this is exactly what some Ajax applications attempt to do. Not content with having a waiter take orders and bring food, they get the waiter to do all the cooking too. Cooking should happen in the kitchen. Application logic belongs on the server. It's better for everyone that way. Your application will work more consistently when it's server-based. The browser environment is simply too unpredictable." I also appreciated Jeremy's subtle sense of humor throughout the book: telling of the origins of the n

Some years ago I found Dan Cederholm's book Web Standards Solutions: The Markup and Style Handbook (Pioneering Series) to be an ideal read from cover to cover. I went on to buy Dan's BulletProof Web Design and found the clarity and pared-down nature of his first book continued into this new 'Bulletproof' brand. So I was delighted to find another Bulletproof book that covered Ajax. Jeremy Keith's Bulletproof Ajax is excellent. I know XHTML, CSS and a little PHP. Jeremy's book has introduced JavaScript to me (finally) in a way I can simply understand, same for the DOM. It worked for me becuase he analogised to the way CSS works. The emphasis on seperation continued through the book. He shows how to add Ajax but not as a piece of a jigsaw, more as a magnifying glass to look at the finished jigsaw with greater power. He shows how a page needs to be built to work and then the Ajax added as a dispensible layer that if unavailable (due to JavaScript being turned off), will not stop the page from working, graceful degrading. A bulletproof approach. If I was a JavaScript guru and DOM master than this book would be a a luxury. As I am a newbie to writing my own JavaScript, traversing the DOM and keen to use Ajax safely to make better user experiences for my clients, I am delighted with this book.

I've written Ajax applications using the XMLhttp object a few times requesting both xml and text responses. I've also use the script.aculo.us library to write Ajax applications. Bulletproof Ajax does more than show you the basic ropes. Bulletproof Ajax explains all the pieces, including xml after-processing. It also demonstrates what Jeremy Keith calls Hijax. I normally write applications for an intranet so had not given unobtrusive Ajax much thought. But just today I discovered that my personal laptop did not have the XML parser installed. So for non-intranet applications, to be sure that the viewer can access your application it had better run without ajax. Jeremy demonstrates how to use Ajax to enhance a web application without enforcing the presence of javascript or the XML parser. Jeremy also presents JSON scripting which he explains is a way to perform defacto Ajax without the limitation of same-site sources. JSON permits, in essence, cross-site ajax. I personally also learned more about javascript object programming than I'd clearly understood previously. Jeremy doesn't assume that you know unstated fundamentals and yet he takes you through these fundamentals without making it a chore. As with his previous book DOM Scripting, Jeremy leads you into confident programming. Using what I learned reading Bulletproof Ajax I just wrote my own object library for Ajax with enhancements I wanted. Now, when developing intranet applications I won't be stuck facing errors resulting from someone else's ajax library which I don't understand and wouldn't want to change or maintain.

Jeremy Keith has been on forefront of upcoming web practices for quite awhile now. He is a member of the Web Standards Project, joint lead of the DOM Scripting Task Force, stresses web standards and accessibly in web design. His website addaciao.com is a great resource of material on the subject and you can pretty much find him at almost any web conference in the world nowadays. This is his second book (Dom Scripting), and it pretty much continues his relentless pursuits of accessibility and unobtrusiveness wherever JavaScript is involved. This book focuses on the creating well structured Ajax web applications but making sure the reader does not forget the most important thing about web sites: their content. If all this fancy-shaky, bells and whistles Ajax stuff prevents a disabled user using a screen reader to be able to view your website content, what is the point? The book is aimed (like his first) at web designers as opposed to programmers. Jeremy does not use fancy techo-bable when regular simple English will suffice. He wants to make sure that anybody can understands the concepts of Ajax and its components (JavaScript, XML, XMLHTTPRequest) can be used properly by anybody who is willing to read it. Not too many books are written like this (unfortunately) and it is a joy to read. Though when you actually see it and how short it is (barely 200 pages with index), you may thing..."this is too short for me to get anything out of this". But you would be so wrong. There are around 10 or so Ajax books out there now (more on the way I'm sure), and I probably have at least half them. I would put this as probably I the top 2 of all the Ajax books out there. IF you are really going to immerse yourself in learning and using Ajax, I would suggest getting one more "BIG" reference type book on it and that would all you would need. This is a must-buy for anybody wanting to learn Ajax with standards, accessibility in mind. Ok, enough about how much I like this book, on with some details about the book: Chapter 1: A nicely illustrated introduction of what Ajax is what pieces comprise it, who started using it, how it is used and why it is so "hype" right now. Chapter 2: A very nice introduction to JavaScript and DOM basics. Honestly, this chapters takes about the best of Jeremy's DOM Scripting Book and condenses it into about 10 pages. Of course it is just a overview of the DOM methods and a brief explanation of each, but it is all you really need to get started. You should buy his DOM Scripting book if you want to get some hands-on experience with the DOM. Or get the JavaScript Reference book from oreilly which is a JavaScript encyclopedia of everything there is to know about it. Chapter 3: XMLHttpRequest - The "meat-and-potatoes" of how Ajax works. Jeremy does a great job of explaning the history of how this object got first developed (IE 5 - XMLRequest) and is used with proper object detection. Chapter 4: Jeremy discusses the good and bad of