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Back to Outline 12 - Agile Project Management and Legacy Code. On to Outline 14 - Course Wrapup.

Summary

We consider the use of design patterns in software design.

Related Pages

Overview

• Design patterns.
• The GoF list of patterns.
• More code smells.

Administrivia

• Welcome back. I hope you had a great Thanksgiving break.
• Welcome to our penultimate week of class!
• Are any students looking for project work over break and planning to be in town over break?
• News.

Assignments

• Read/view Chapter 12, Practical DevOps.
• No more programming assignments!

Design Patterns

• Inspired by C. Alexander's work on Architecture, A Pattern Language.
• Leading OO-programmers/designers looked at common software architecture tasks/problems and came up with a taxonomy of common solutions to those problems.
• Valuable in (at least) two ways
  • For novice programmers, provides better approaches to tasks that they don't realize are old.
  • For experienced programmers, provides a language to talk about approaches.
• There are growing movements to write "patterns" (and "anti-patterns") for many different classes of problems. There are even teaching patterns.

SOLID Principles

Intended as a mechanism for thinking about class design. Five basic principles.

• Single Responsibility - Do one thing well.
• Open/Closed - Open for extension, closed against modification.
• Liskov Substitution Priniplce - T's subclasses follow the interface
• Dependency Injection
• Demeter -

Patterns

Creational

• Abstact Factory
• Factory Method
• Singleton
• Prototype
• Builder

Structural

• Adapter
• Proxy
• Facade
• Bridge
• Decorator
• Composite
• Flyweight

Behavioral

• Template Method
• Strategy
• Observer
• Iterator
• Visitor
• State
• Chain of Responsibility
• Mediator
• Interpreter
• Command

More Smells

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