Packt Publishing, the same book publishing company that sent me the Dojo book, has offered me another free book in exchange for a review, this time on the JavaScript framework Ext JS. I don’t consider myself an expert book reviewer, however, it sounded like another a great opportunity/excuse to learn something new, so I took them up on it.

The book is titled Learning Ext JS and is written by Shea Frederick, Steve ‘Cutter’ Blades, and Colin Ramsay. So far I’ve read about 60 pages, and it’s looking like it’s going to be a pretty good book. It’s paced well and the authors seem to have a good sense of humor (they introduce Ext JS message boxes using a character from Office Space), though I still have around 190 pages left, so there’s still a long way to go.

Example Ext JS Message Box

Ext JS doesn’t appear to be too different from other JavaScript frameworks I’ve tried, though its main focus seems to be in creating slick looking web interfaces. It was originally created as an extension to the Yahoo User Interface (YUI) library, however, due to its popularity, it ended up growing into a stand alone JavaScript framework. Since it was developed with YUI in mind, it initially required YUI to be present to do the behind the scenes work. This changed over time, first with adapters being written so other frameworks (like jQuery and Prototype) could be used to do the core functionality, and then later so that Ext JS came as a complete, stand alone product. Though during this last phase they did keep the hooks in so that you could still use an adapter and have another framework to do the behind the scenes work if you wanted.

From what I’ve seen of Ext JS so far, it’s looks pretty impressive. The offical
Feed Reader and Web Desktop sample apps look especially cool. The only negative I can see, which was initially pointed out to me by Sloat, is that license for the library is the GPL. This means that apps you write using it would be under the GPL and you would have to release the code for them under the GPL. You can avoid doing this by purchasing a commercial license, though this would cost you between $289 and $18,699, depending on the license and support options you picked.

Knowing this, I probably wouldn’t write any large applications using Ext JS, unless I planned to purchased a license. However, for most of the stuff I write, I don’t mind the source code being available, so having to use the GPL is annoying but not a deal breaker. This is something you should think about before you decide to use the Ext JS library though, because this license requires that you release your source code under the GPL.

Anyway, hopefully this experience will lead me to learning a couple of new tricks and being able to create some nicer looking apps. Instead of waiting until I finish the book to do any kind of in depth work with the framework, I think I’m going to try and be a little more interactive this time and write stuff as I go. That way I don’t end up ignoring this site.

So I’ve finished reading my copy of the book Learning Dojo By Peter Svensson. It was a pretty easy read and contained a lot of good info. Overall it’s an okay book, though there are parts where it seems a little rough around the edges, however, I’ll get to why I think that in a bit.

So what is Dojo? Dojo is a free JavaScript toolkit similar to YUI and jQuery, though it bills itself as being larger in terms of features and functionality than the existing JavaScript toolkits. Visually, the widgets it provides (which Dojo refers to as Dijits) are pretty slick and easy to use. You can see a demo of many of them here (this link is unrelated to the book).

Dojo is for people who know JavaScript and who want to add more gagets to their development tool belt. Even though Dojo offers alternative ways to do certain things (like inheritance and finding elements by their ID), you can’t really use it unless you have a decent understanding of JavaScript. Well, you could, but you wouldn’t get very far.

Learning Dojo appears to be aimed at giving web developers a broad introduction on what Dojo can do. It starts off with a two chapters introducing Dojo and then follows them by having chapters dedicated to a particular area of interest – like Forms, Dijits (what Dojo calls widgets), Layouts, Ajax, etc. The author even provides the Layout chapter online as a preview for the book, it’s located here. That chapter gives a good sampling of what the author’s writing style is like.

Overall I thought the book was decent. It’s not something I’d rave about, but its a solid book and contained a lot of info and examples. I feel like it gave a nice introduction to what Dojo is and how it could be used in the real world. I found the chapter on “Data, Trees, and Grids” useful. I had been wondering about easy ways to do grids and to read RSS feeds (the book didn’t discuss RSS feed reading, but it mentioned a library that could do it), so I was pleasantly surprised to come across this info.

My only criticisms of the book were some formatting, editing and spelling issues I ran into. Around 5% of the code examples had indentation issues. The tabs would be aligned incorrectly in certain parts of the example. I’m guessing its because a mixture of space and tab characters were used. However, I don’t know, and these examples were still readable. This was mostly just an annoyance. Also, at the very end of Chapter Two, the “JSON” section had 3 small examples where the code was not printed correctly and it was unreadable. This was upsetting, though it was the only place where I encountered this.

Anyway, if you’re looking for a book on Dojo, Learning Dojo, while rough around the edges, does provide a decent introduction and contains some handy examples.

Also, like I mentioned in a previous post, I was sent this book for free by the publisher with the only condition being that I write a review of what I thought. I don’t get any money if you buy it.

And lastly, if you want to play around with Dojo, you can download it for free at their website.

A few days after I posted my previous entry on the JavaScript books I was reading, I got an email from a book publishing company asking if I was interested in a free review copy of their latest JavaScript book. I was a little skeptical at first, however, after a brief chat, the only string attached was that I write blog entry on what I thought of the book. This seemed like a fair deal, so I decided to take them up on it.

Since I’m getting something for free, I figured the honest thing to do would be to open about it so people don’t think my opinions are biased, since I do tend to gush about stuff I like (YUI, Google Alerts, etc.). When I don’t like something, I usually just don’t write about it. However, if this book ends up sucking, I will be brutally honest about how much it sucks. Though based strictly on chapter 1, the book appears as if it will be a pretty decent read.

Anyway, the topic of the book is The Dojo Toolkit. Dojo is a free open source JavaScript library that provides a number of widgets and utilities, much like jQuery and YUI. Right now I’m unsure of how it compares to these other frameworks, but it looks very promising based on what I’ve seen so far from various Dojo websites. The charting package looked particularly interesting.

Hopefully I’ll learn a lot of cool stuff about Dojo. I wont pretend to be a JavaScript expert, so the review I’ll write will most likely be in the same style as my last review – though probably a bit more thorough. For those of you who are curious, the book is called “Learning Dojo” (that’s the book’s actual website, this is not a sponsored link and I don’t get anything if you buy the book – not that you shouldn’t buy it, I just want to be clear since that page is mostly about buying the book).

After I finish this new book I’m going to get back to my JavaScript Design Patterns book (which it’s really good so far – though I’d only recommend it to hardcore JavaScript developers). And after that I’m going to get back to writing stuff for this site. Hopefully all of this reading will pay off with some nicer apps, tutorials, and programming examples.