Principles of Package Design

1. Front Matter

   Pages i-xix

   PDF

2. Class Design

   1. Front Matter

      Pages 1-2

      PDF

   2. The Single Responsibility Principle

      • Matthias Noback

      Pages 3-10

   3. The Open/Closed Principle

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      Pages 11-30

   4. The Liskov Substitution Principle

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      Pages 31-53

   5. The Interface Segregation Principle

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      Pages 55-66

   6. The Dependency Inversion Principle

      • Matthias Noback

      Pages 67-104

3. Package Design

   1. Front Matter

      Pages 105-114

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   2. The Release/Reuse Equivalence Principle

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      Pages 115-144

   3. The Common Reuse Principle

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      Pages 145-170

   4. The Common Closure Principle

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      Pages 171-184

   5. The Acyclic Dependencies Principle

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      Pages 185-216

   6. The Stable Dependencies Principle

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      Pages 217-235

   7. The Stable Abstractions Principle

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      Pages 237-249

   8. Conclusion

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      Pages 251-256

4. Back Matter

   Pages 257-275

   PDF

Apply design principles to your classes, preparing them for reuse. You will use package design principles to create packages that are just right in terms of cohesion and coupling, and are user- and maintainer-friendly at the same time.

The first part of this book walks you through the five SOLID principles that will help you improve the design of your classes. The second part introduces you to the best practices of package design, and covers both package cohesion principles and package coupling principles. Cohesion principles show you which classes should be put together in a package, when to split packages, and if a combination of classes may be considered a "package" in the first place. Package coupling principles help you choose the right dependencies and prevent wrong directions in the dependency graph of your packages.


What You'll Learn

• Apply the SOLID principles of class design
• Determine if classes belong in the same package
• Know whether it is safe for packages to depend on each other

Who This Book Is For


Software developers with a broad range of experience in the field, who are looking for ways to reuse,share, and distribute their code

• SOLID principles
• package design principles
• object design
• component design
• dependencies
• coupling
• cohesion
• reusability
• Domain-Driven Design
• object design
• test-driven development

• Zeist, The Netherlands

  Matthias Noback

Matthias Noback is a professional PHP developer. He runs his own web development, training, and consultancy company called Noback's Office. In the past, he has worked as a software developer at Driebit (Amsterdam) and IPPZ (Utrecht), and as CTO at Ibuildings (Utrecht). Since 2011 he has been regularly writing on his blog about advanced software development topics. Favorite topics include software architecture, legacy code, testing, and object design. Other books by Matthias are A Year with Symfony and Microservices for Everyone.

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