Learning Ext JS 133
stoolpigeon writes "Rich Internet Applications (RIA) have often been associated with some type of sandbox or virtual machine environment to make desktop features available via the web. Many applications though, have left behind the restrictions and demands of those technologies, implementing RIAs as pure web interfaces. One key technology in this area is JavaScript. It's been well documented that working with JavaScript can be problematic across various browsers. In response a number of JavaScript libraries have been created to alleviate the issues in dealing with different browsers, allowing developers to focus on application logic rather than platform concerns. One such library, focused on providing tools for building RIAs is Ext JS. For the aspiring developer looking to use Ext JS, Packt provides a guide to the library in the form of Learning Ext JS." Read on for the rest of JR's review.
The book is written for people with experience in doing web development. The authors state that a working knowledge of HTML and CSS are important, but experience with JavaScript is not essential. I think that a reader that has not used JavaScript may want to supplement this guide with something that covers the basics of JS. Experienced developers that haven't worked specifically with web programming should have no trouble keeping up. Anyone completely new to the idea of programming, scripting, markup, etc. really will need to take some time to get familiar with those concepts before they dive into this book. The authors do not spend time teaching programming, they are focused purely on realistic applications of Ext JS. | Learning Ext JS | |
| author | Shea Frederick, Colin Ramsay, Steve 'Cutter' Blades |
| pages | 309 |
| publisher | Packt Publishing |
| rating | 8/10 |
| reviewer | JR Peck |
| ISBN | 978-1-847195-14-2 |
| summary | Build dynamic, desktop-style user interfaces for your data-driven web applications. |
The authors begin by stating that, "Ext is not just another JavaScript library..." and it is understandable that they would feel this way. I am unsure why one wouldn't think so other than a personal preference for the product. That said Ext JS can be used alongside other JS libraries and does provide a lot of features 'out of the box' that make it an attractive choice. The emphasis on RIA widgets and building strong applications is nice as Ext JS is not working to be all things to all developers.
The book is heavy on code and examples but not so much so that it falls into the cook-book style of writing. Learning Ext JS is more of an extended tutorial with ample explanation to help the reader not only understand the code but why certain choices are made. Frederick, Ramsay and Blades have done a good job of working through the examples in a concise manner. While the book is the result of group work, it does not have the feeling of being written by a community. I did not run into an abundance of repetition and topics flowed well. Learning Ext JS also covers installation and integration of the library as well as a very quick survey of tools for development. While short these sections would be extremely important to anyone coming into web development with little experience.
It's a quick read, and doesn't delve extremely deeply into more advanced topics. Rather, a reader new to Ext JS will get a launch that should make the library usable in a practical way and also give them the framework to push deeper. The book was written and published just as Ext JS moved between versions. The new version is backwards compatible with the material in this book and a number of the changes in version three would not have fallen within the scope of this book, so it is still a good place to get started with Ext JS. Those who want to dig deeper will need to look elsewhere.
The brevity of the book wont work for those folks who want to really dig down deep into Ext JS. I on the other hand, wasn't looking for a massive tome to lug around and grind through. I was happy to have a very accessible tool that would get me started quickly and that is what I got. On the other hand I do like to be able to find what I need quickly and nothing is more important to me when learning than a solid index. Unfortunately the only really large ding I have for the book is that the index is weak. It would be a lot worse if the book were larger, so the brevity helps here a bit, but it's still unfortunate. This does make the ebook version a little more attractive. Packt will bundle them at a cost that makes the addition of the electronic copy very attractive. That said, the easy flow does it make it easy to read this book front to back while working the examples. Learning Ext JS just wont be my first choice when I need to quickly check a reference.
I've discussed the shallow coverage, but this does not mean that the book is not useful. The Ext JS library bundles enough functionality into the stock widgets, that decent applications could be written with nothing more. Creating custom widgets is covered and extending existing code as well, but this is later in the book. The material prior to that covers not only the use of the provided widgets but how to tie them together, theme an app and then handling data. This means the reader pretty much has everything in hand to build a stock application. The focus is on dealing with these issues on the client side. The examples do include a small amount of back end code when necessary for the execution of examples. All the examples are available to download from the Packt site and come packaged with all necessary scripts, images, etc.
I've always worked primarily with desktop applications. I've done some work with web applications, but it seems to me that increasingly the tools that I use the most are web based. With technology like Google Gears making those applications available whether I'm connected or not they have become much more attractive. Tools like Ext JS make it much easier for me to transition over to this new way of developing applications. I've found that Learning Ext JS has been a valuable resource in taking what is a great resource and allowing me to get the most out of it more rapidly than I would have otherwise.
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Another Book (Score:5, Informative)
I've been using Ext JS for a little while now and when I went looking for books I saw the reviewed book and another one titled "Ext JS in Action" ( http://manning.com/garcia/ [manning.com] ). I ended up choosing the latter. While it is still in the process of being written the publisher has a early access program that allows you to get the chapters as they are written. I would definitely recommend the book to others interested in learning Ext JS.
Re:Crossbrowser libraries just perpetuate the prob (Score:5, Informative)
"But my customers want it to work in their browser!" is not an argument when better browsers are freely available.
Really? When your customers contact you about this or that not working right in IE, all you tell them is to use a different browser? Don't you think that's a bit lazy?
How "standard" is a "standard" if people aren't following it?
It's pretty bad when more than half the time ona web project is "fixing" broken IE rendering.
Oddly enough, the exact reason I don't have to spend a considerable amount of time debugging IE is because I use a library that is cross-browser compatible, because of things like browser sniffing. My time spent debugging problems in IE has dropped significantly since starting with ExtJS.
Re:The guys behind EXTJS are terrible (Score:4, Informative)
You are correct: you are distributing the GPL code, you would have to put the javascript code you wrote under the GPL as well. This is the reason why most javascript libraries go with the BSD license or LGPL.
Then again, you are distributing your own code ("proprietary" or not) anyway.
Re:The guys behind EXTJS are terrible (Score:5, Informative)
Mod parent up.
The LGPL debacle was a single instance. Many people put way too much weight on it than necessary - if you look at the entire history of the company, they have been extremely responsive and credible. My company's story shares many commonalities with the above. I have worked with extJS back when it was called yui-ext, so named because it was an set of add ons to the Yahoo User Interface libraries. Jack Slocum was a responsive, dedicated developer back then, and remains so to this day. For a long time he developed widgets in his spare time, and once demand was high enough and he wasn't getting compensated for his time enough he decided to monetize it. As with any business, there are growing pains and mistakes that get made, but to describe the licensing change as a stab in the back is hardly accurate.