Programming Flex 2

Chapter 5. Framework Fundamentals

Much of what Flex does is to simplify application development. In order to do that, Flex does a lot behind the scenes. In many cases, you don’t need to know about these things in order to build applications with Flex. However, as you try to achieve more complex and sophisticated goals using Flex, you’ll likely find that it is important to understand how Flex works at a more fundamental level. This chapter is all about these behind-the-scenes low-level functionalities and behaviors. You’ll learn about the life cycle for Flex applications, differentiating between Flash Player and Flex class libraries, bootstrapping Flex applications, partitioning loaded applications into application domains, and more.

Understanding the Flex Application Life Cycle

Although it’s possible to build some Flex applications without having an understanding of the application life cycle, it will behoove you to know the basic mechanics: the order in which things occur. This will help you configure features such as customized preloaders, do things such as load other Flex applications at runtime, and manage the process of loading and unloading class libraries and assets at runtime. Furthermore, a good understanding of the Flex application life cycle will enable you to build better applications because you will know where to optimally run code. For example, if you need to ensure that some code runs during a preloader, you need to know where to place the code for that event. An understanding ...