This chapter introduces a new case study, which comes from the area of e-commerce (electronic commerce over the Internet). It also begins a solution using the Strategy pattern. I return to this case study in Chapter 16, “The Analysis Matrix.”
• Returns to the problem of new requirements and describes approaches to handling new variations of an existing theme.
• Explains which approach is consistent with the Gang of Four’s philosophy and why.
• Introduces the new case study.
• Describes the Strategy pattern and shows how it handles a new requirement in the case study.
• Describes the key features of the Strategy pattern.