Archive for the 'Composite' Category

This is part 1 of a two part composite pattern example implemented in ActionScript 3. The composite pattern comes in handy to develop complex structures consisting of simpler parts or components. The components can be primitive objects or they can be containers that hold other components. An example will help explain this better. Think of a house as a composite object. A house consists of a roof and several rooms (living spaces). Each room can contain windows, chairs etc. The house and rooms are composite objects as they contain other components. However, we can consider the roof, windows, beds and chairs as primitive objects. The composite pattern makes building, accessing, and manipulating composite structures simple by enabling the client to treat both composite objects (that contain other objects) and components (primitive objects) the same way through a common interface.

The following example develops a book in Flash. A book is a composite object as it contains several pages. This is by no means a functional book, but a conceptual example to illustrate the utility of the composite pattern. One of the big advantages of design patterns is extensibility: allowing the application to expand and add new features without breaking existing functionality. We will extend this example in part 2 by adding composite pages that can contain text and images.
Continue reading ‘Composite Pattern: Book (Part 1)’