The book has been published a long time, and today want to look up, Reviewing the Old it!
What design patterns?
Christopher Alexander (Christopher • Alexander) said: "Each pattern describes a constantly recurring problem around us, and the core of the solution to this problem so that you can once again use the program without having to repeat. labor."
Four elements model
1. model name: a mnemonic name, description of the problem patterns, solutions and effects.
2. Question: describes the mode should be used and when.
3. Solution: describes the design of components, the relationship between them and their respective responsibilities, and collaborate.
4. Effects: describes the problem and the mode of application usage patterns should be weighed against the effect of.