Up to this point in the book, we’ve looked at how to use Flex to build web applications. However, Flex 3 allows you to build more than web applications. It also allows you to build AIR applications for the desktop. In this chapter, you’ll learn about Adobe AIR and how to use Flex to build AIR applications.
Adobe AIR allows developers to use Flash, Flex, and/or HTML/Ajax to create desktop applications. As this is a book about Flex, we’ll only look at using Flex to build AIR applications in this chapter.
AIR is a platform consisting of a runtime environment and developer tools for creating AIR applications. The runtime environment, called the AIR runtime, is a free download from Adobe that users must have installed on their computers to run AIR applications. Conceptually, this runtime environment is very similar to other common runtime environments such as the .NET runtime and the Java runtime. The basic concept is that developers can build applications that run in the runtime environment, allowing for a simple way to create cross-platform applications.
Building an AIR application with Flex is remarkably easy. You can build a basic AIR application using what you learned in the other chapters in this book, together with just a few workflow and technical changes that you’ll read about in the next section. However, you can do more in an AIR application than merely run a standard Flex application in the AIR runtime instead of in a web browser. The AIR runtime enables an AIR-only feature set, which includes the following:
Working with the local filesystem (e.g., writing files)
Creating and accessing local SQL databases
Creating and managing application windows
Working with system clipboards (including interapplication drag and drop and copy and paste)
Rendering HTML within the Flex application and supporting all HTTP verbs (GET, POST, PUT, and DELETE)
Throughout this chapter, you’ll learn how to configure, compile, and deploy AIR applications, and you’ll learn how to work with all the features from the preceding list. However, we should note that this chapter is not intended to be a comprehensive guide to building AIR applications. That would require an entire book. Instead, the goal of this chapter is to provide you with the basic information you’ll need to start building AIR applications using Flex. We recommend that you read the AIR document at Adobe’s web site (http://www.adobe.com/go/learn_air_flex3) as well as the Flex language reference (http://www.adobe.com/go/learn_flex3_aslr) for more detail.