Preface
| If you know HTML, CSS, and JavaScript, you already have the tools you need to develop Android applications. This hands-on book shows you how to use these open source web standards to design and build apps that can be adapted for any Android device -- without having to use Java. Buy the print book or ebook or purchase it in iBooks. |
Thanks to mobile phones, we have moved from virtually no one having access to information, to virtually everyone having access to the vast resources of the web. This is arguably the most important achievement of our generation. Despite its overarching importance, mobile computing is in its infancy. Technical, financial, and political forces have created platform fragmentation like never before, and it’s going to get worse before it gets better.
Developers who need to engage large and diverse groups of people are faced with a seemingly impossible challenge – "How do we implement our mobile vision in a way that is feasible, affordable, and reaches the greatest number of participants?" In many cases, the answer is web technologies. The combination of advances in HTML5 and mobile devices has created an environment where even novice developers can build mobile apps that improve people’s lives on a global scale.
Google's Android operating system is a compelling addition to the mobile computing space. In true Google fashion, the platform is open, free, and highly interoperable. The development tools are full-featured and powerful, if a bit geeky, and run on variety of platforms.
Carriers and handset manufacturers have jumped on the Android bandwagon. The market is beginning to flood with Android devices of all shapes and sizes. This is a double-edged sword for developers. On one hand, more devices means a bigger market. On the other hand, more devices means more fragmentation. As with the fragmentation in the general mobile market, fragmentation on Android can often be addressed by building apps with HTML, CSS, and JavaScript.
I’m the first to admit that not all apps are a good fit to be built with web technologies. That said, I see a lot of apps written with native code that could’ve just as easily been done with HTML. When speaking to developers who aren’t sure which approach to take, I say this:
If you can build your app with HTML, CSS, and JavaScript, then you probably should.
Using open source, standards based web technologies gives you the greatest flexibility, the broadest reach, and the lowest cost. You can easily release as a web app, and debug and test it under load with thousands of real users. Once you are ready to rock, you can use PhoneGap to convert your web app to a native Android app, add a few device-specific features if you like, and submit to the Android Market—or offer for it download from your web site. Sounds good, right?
Who Should Read This Book
I’m going to assume that you have some basic experience reading and writing HTML, CSS, and JavaScript (jQuery in particular). I will be including some basic SQL code in Chapter 5, Client-Side Data Storage so a passing familiarity with SQL syntax would be helpful but is not required.
What You Need to Use This Book
This book is going to avoid the Android SDK wherever possible. All you’ll need to follow along with the vast majority of examples is a text editor and the most recent version of Google Chrome (a cutting edge web browser that’s available for both Mac and Windows at http://www.google.com/chrome). You do need to have the Android SDK for the PhoneGap material in Chapter 7, Going Native, where I explain how to convert your web app into a native app that you can submit to the Android Market.
Conventions Used in This Book
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Constant width italic Shows text that should be replaced with user-supplied values or by values determined by context.
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