Dependency Injection Principles, Practices, and Patterns

2 Writing tightly coupled code

In this chapter

• Writing a tightly coupled application
• Evaluating the composability of that application
• Analyzing the lack of composability in that application

As we mentioned in chapter 1, a sauce béarnaise is an emulsified sauce made from egg yolk and butter, but this doesn’t magically instill in you the ability to make one. The best way to learn is to practice, but an example can often bridge the gap between theory and practice. Watching a professional cook making a sauce béarnaise is helpful before you try it out yourself.

When we introduced Dependency Injection (DI) in the last chapter, we presented a high-level tour to help you understand its purpose and general principles. But that simple explanation doesn’t ...