tailieunhanh - advanced Flex Application Development Building Rich Media X phần 6

ang bị màn hình này, tôi có thể mở Flex và bắt đầu cài đặt các mô-đun thực tế. Trước khi tôi thực sự bắt đầu thiết kế và mã hóa mặc dù, tôi mất một thời gian để thiết lập môi trường phát triển của tôi với các lớp cốt lõi mà tôi muốn sử dụng. | USER COMMUNICATIONS Figure 9-3. Admin policies templates screen Figure 9-4. Partner e-mail templates screen 235 CHAPTER 9 Figure 9-5. Partner e-mail blast screen In the beginning there was Actionscript Armed with these screens I could then open up Flex and start setting up the actual modules. Before I actually started designing and coding though I took some time to set up my development environ- ment with the core classes that I like Figure 9-6. Custom application skeleton to use. My application skeletons always include a series of Singleton classes that allow me to manage an application s functionality much more easily than without. Singleton classes in this context refers to ActionScript classes that are coded using the Singleton design pattern which as I mentioned in Chapter 7 is used to restrict instantiation of a class to one object. This is accomplished via a class method usually getInstance that creates a new instance of the class if one does not exist. If an instance already exists it simply returns a reference to that class. This approach is very useful when you need only one instance of a class to coordinate actions across an entire system or application. By having a set of templates already prepared I save myself a considerable amount of time by not having to type the code for these from scratch on every project. Figure 9-6 shows a listing of the classes I include at the start of a project. 236 USER COMMUNICATIONS Overview of the ServiceUtil class As you can see the package is the most extensive because this is where the majority of the heavy lifting takes place. It represents my modified version of the Model-ViewController MVC concept. Before I describe the classes in this package I d like to take a moment to describe the ServiceUtil class. At Almer Blank we do a lot of remoting with AMFPHP . In the early stages we had to ensure we always had the proper dependencies ActionScript files included and had to do a bunch of