Summary
Design is normally thought of as a process of synthesis, a process of putting things together. In software, a common approach is to look immediately for objects and classes and components and then think about how they should fit together.
In The Timeless Way of Building, Christopher Alexander described a better approach, one that is based on patterns:
1. |
Start out with a conceptual understanding of the whole in order to understand what needs to be accomplished. |
2. |
Identify the patterns that are present in the whole. |
3. |
Start with those patterns that create the context for the others. |
4. |
Apply these patterns. |
5. |
Repeat with the remaining patterns, as well as with any new patterns that were discovered along the way. |
6. |
Finally, refine the design and implement within the context created by applying these patterns one at a time. |
As a software developer, you may not be able to apply Alexander's pattern language approach directly. However, designing by adding concepts within the context of previously presented concepts is surely something that all of us can do. Keep this in mind as you learn new patterns later in this book. Many patterns create robust software because they define contexts within which the classes that implement them can work.