Style Guide for Object Design

Retired

This book is no longer available for sale.

Style Guide for Object Design

  • 379

    Readers

  • 285

    Pages

  • English

  • PDF

  • EPUB

  • MOBI

  • WEB

About the Book

Note: this book is no longer available via Leanpub. It has been republished by Manning Publications: https://www.manning.com/books/object-design-style-guide Manning also offers a print edition, which will be shipped at the end of the early access program.

This book is right in the middle between learning how to write code and learning how to apply design principles and patterns. Using lots of code samples it teaches you the basics of object design. It provides you with simple rules to follow when defining your classes, methods, properties and interfaces.

After the fundamentals, this book provides you with a discussion of object design related topics that are worth investigating.

About the Author

Matthias Noback
Matthias Noback

Matthias Noback has been building web applications since 2003. He is the author of Principles of Package Design and Object Design Style Guide and Advanced Web Application Architecture. He is a regular blogger, public speaker and trainer.

Table of Contents

  •  
    • Foreword
    • Introduction
      • Who is this book for?
      • Design rules for this book
      • Conventions
      • Overview of the contents
      • Acknowledgments
  • The lifecycle of an object
    • 1. Creating services
      • 1.1 Inject dependencies and configuration values as constructor arguments
        • Keeping together configuration values that belong together
      • 1.2 Inject what you need, not where you can get it from
      • 1.3 All constructor arguments should be required
      • 1.4 Only use constructor injection
      • 1.5 There’s no such thing as an optional dependency
      • 1.6 Make all dependencies explicit
        • Turn static dependencies into object dependencies
        • Turn complicated functions into object dependencies
        • Make system calls explicit
      • 1.7 Data relevant for the task should be passed as method arguments instead of constructor arguments
      • 1.8 Don’t allow the behavior of a service to change after it has been instantiated
      • 1.9 Do nothing inside a constructor, only assign properties
      • 1.10 Throw an exception when an argument is invalid
      • 1.11 Define services as an immutable object graph with only a few entry points
      • 1.12 Summary
    • 2. Creating other objects
      • 2.1 Require the minimum amount of data needed to behave consistently
      • 2.2 Require data that is meaningful
      • 2.3 Don’t use custom exception classes for invalid argument exceptions
      • 2.4 Extract new objects to prevent domain invariants from being verified in multiple places
      • 2.5 Extract new objects to represent composite values
      • 2.6 Use assertions to validate constructor arguments
      • 2.7 Don’t inject dependencies, optionally pass them as method arguments
      • 2.8 Use named constructors
        • Create from primitive type values
        • Don’t immediately add toString(), toInt(), etc.
        • Introduce a domain-specific concept
        • Optionally use the private constructor to enforce constraints
      • 2.9 Don’t use property fillers
      • 2.10 Don’t put anything more into an object than it needs
      • 2.11 Don’t test constructors
      • 2.12 The exception to the rule: Data transfer objects {#the-exception-to-the-rules:-data-transfer-objects}
        • Use public properties
        • Don’t throw exceptions, collect validation errors
        • Use property fillers when needed
      • 2.13 Summary
    • 3. Manipulating objects
      •  
        • Entities: identifiable objects which track changes and record events
        • Value objects: replaceable, anonymous, and immutable values
        • Data transfer objects: simple objects with fewer design rules
      • 3.1 Prefer immutable objects
        • Replace values instead of modifying them
      • 3.2 A modifier on an immutable object should return a modified copy
      • 3.3 On a mutable object, modifier methods should be command methods
      • 3.4 On an immutable object, modifier methods should have declarative names
      • 3.5 Compare whole objects
      • 3.6 When comparing immutable objects, assert equality, not sameness
      • 3.7 Calling a modifier method should always result in a valid object
      • 3.8 A modifier method should verify that the requested state change is valid
      • 3.9 Use internally recorded events to verify changes on mutable objects
      • 3.10 Don’t implement fluent interfaces on mutable objects
      • 3.11 Summary
  • Using objects
    • 4. A template for implementing methods
      • 4.1 Pre-condition checks
      • 4.2 Failure scenarios
      • 4.3 Happy path
      • 4.4 Post-condition checks
      • 4.5 Return value
      • 4.6 Some rules for exceptions
        • Use custom exception classes only if needed
        • Naming invalid argument or logic exception classes
        • Naming runtime exception classes
        • Use named constructors to indicate reasons for failure
        • Add detailed messages
      • 4.7 Summary
    • 5. Retrieving information
      • 5.1 Use query methods for information retrieval
      • 5.2 Query methods should have single-type return values
      • 5.3 Avoid query methods that expose internal state
      • 5.4 Define specific methods and return types for the queries you want to make
      • 5.5 Define an abstraction for queries that cross system boundaries
      • 5.6 Use stubs for test doubles with query methods
      • 5.7 Query methods should use other query methods, no command methods
      • 5.8 Summary
    • 6. Performing tasks
      • 6.1 Use command methods with a name in the imperative form
      • 6.2 Limit the scope of a command method, use events to perform secondary tasks
      • 6.3 Make services immutable from the outside as well as on the inside
      • 6.4 When something goes wrong, throw an exception
      • 6.5 Use queries to collect information, commands to take the next steps
      • 6.6 Define an abstraction for commands that cross system boundaries
      • 6.7 Only verify calls to command methods with a mock
      • 6.8 Summary
    • 7. Dividing responsibilities
      • 7.1 Separate write models from read models
      • 7.2 Create read models that are specific for their use cases
        • Create read models directly from their data source
        • Build read models from domain events
      • 7.3 Summary
  • Changing the behavior of objects
    • 8. Changing the behavior of services
      • 8.1 Introduce constructor arguments to make behavior configurable
      • 8.2 Introduce constructor arguments to make behavior replaceable
      • 8.3 Compose abstractions to achieve more complicated behavior
      • 8.4 Decorate existing behavior
      • 8.5 Use notification objects or event listeners for additional behavior
      • 8.6 Don’t use inheritance to change an object’s behavior
      • 8.7 Mark classes as final by default
      • 8.8 Mark methods and properties private by default
      • 8.9 Summary
  • A field guide to objects
    • 9. Controllers
    • 10. Application services
    • 11. Write model repositories
    • 12. Entities
    • 13. Value objects
    • 14. Event listeners
    • 15. Read models and read model repositories
    • 16. Abstractions, concretions, layers, and dependencies
    • 17. Summary
  • Epilogue
    • 18. Architectural patterns
    • 19. Testing
      • 19.1 Class testing versus object testing
      • 19.2 Top down feature development
    • 20. Domain-Driven Design
    • 21. Conclusion
    • Changelog
      • 6/3/2019
  • Notes

Authors have earned$9,886,858writing, publishing and selling on Leanpub, earning 80% royalties while saving up to 25 million pounds of CO2 and up to 46,000 trees.

Learn more about writing on Leanpub

The Leanpub 45-day 100% Happiness Guarantee

Within 45 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

See full terms

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers), EPUB (for phones and tablets) and MOBI (for Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses! Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks. Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. It really is that easy.

Learn more about writing on Leanpub

Top Books

  1. #1

    C++ Best Practices

    Jason Turner

    Level up your C++, get the tools working for you, eliminate common problems, and move on to more exciting things!

  2. #2
  3. #3

    Functional Design and Architecture

    Alexander Granin

    Software Design in Functional Programming, Design Patterns and Practices, Methodologies and Application Architectures. How to build real software in Haskell with less efforts and low risks. The first complete source of knowledge.

  4. #4

    Atomic Kotlin

    Bruce Eckel and Svetlana Isakova

    For both beginning and experienced programmers! From the author of the multi-award-winning Thinking in C++ and Thinking in Java together with a member of the Kotlin language team comes a book that breaks the concepts into small, easy-to-digest "atoms," along with exercises supported by hints and solutions directly inside IntelliJ IDEA!

  5. #5
  6. #6

    I am a Software Engineer and I am in Charge

    Alexis Monville and Michael Doyle

    I am a Software Engineer and I am in Charge is a real-world, practical book that helps you increase your impact and satisfaction at work no matter who you work with.

    In the book, we will follow Sandrine, a fictional character who learns to think in a new way enabling her to take a different course of action.

  7. #7

    C++20

    Rainer Grimm

    C++20 is the next big C++ standard after C++11. As C++11 did it, C++20 changes the way we program modern C++. This change is, in particular, due to the big four of C++20: ranges, coroutines, concepts, and modules.

  8. #8

    Invest In Digital Health - The Medical Futurist's Guide

    Dr. Bertalan Mesko

    Artificial Intelligence and Digital Health are booming. In this book, we explain why now it's a good time to invest in Digital Health and give recommendations on where to invest by looking at the top 24 technological trends we find the most promising.

  9. #9

    Ansible for DevOps

    Jeff Geerling

    Ansible is a simple, but powerful, server and configuration management tool. Learn to use Ansible effectively, whether you manage one server—or thousands.

  10. #10

    The Hundred-Page Machine Learning Book

    Andriy Burkov

    Everything you really need to know in Machine Learning in a hundred pages.

Top Bundles

  1. #1

    Software Architecture for Developers: Volumes 1 & 2 - Technical leadership and communication

    2 Books

    "Software Architecture for Developers" is a practical and pragmatic guide to modern, lightweight software architecture, specifically aimed at developers. You'll learn:The essence of software architecture.Why the software architecture role should include coding, coaching and collaboration.The things that you really need to think about before...
  2. #2

    CCIE Service Provider Ultimate Study Bundle

    2 Books

    Piotr Jablonski, Lukasz Bromirski, and Nick Russo have joined forces to deliver the only CCIE Service Provider training resource you'll ever need. This bundle contains a detailed and challenging collection of workbook labs, plus an extensively detailed technical reference guide. All of us have earned the CCIE Service Provider certification...
  3. #3

    The Future of Digital Health

    6 Books

    We put together the most popular books from The Medical Futurist to provide a clear picture about the major trends shaping the future of medicine and healthcare. Digital health technologies, artificial intelligence, the future of 20 medical specialties, big pharma, data privacy and how technology giants such as Amazon or Google want to conquer...
  4. #4

    Cisco CCNA 200-301 Complet

    4 Books

    Ce lot comprend les quatre volumes du guide préparation à l'examen de certification Cisco CCNA 200-301.
  5. #5

    Modern Management Made Easy

    3 Books

    Read all three Modern Management Made Easy books. Learn to manage yourself, lead and serve others, and lead the organization.
  6. #6

    CCDE Practical Studies (All labs)

    3 Books

    CCDE lab
  7. #7

    Modern C++ by Nicolai Josuttis

    2 Books

  8. #8

    "The C++ Standard Library" and "Concurrency with Modern C++"

    2 Books

    Get my books "The C++ Standard Library" and "Concurrency with Modern C++" in a bundle. The first book gives you the details you should know about the C++ standard library; the second one dives deeper into concurrency with modern C++. In sum, you get more than 600 pages full of modern C++ and about 250 source files presenting the standard library...
  9. #9

    Linux Administration Complet

    4 Books

    Ce lot comprend les quatre volumes du Guide Linux Administration :Linux Administration, Volume 1, Administration fondamentale : Guide pratique de préparation aux examens de certification LPIC 1, Linux Essentials, RHCSA et LFCS. Administration fondamentale. Introduction à Linux. Le Shell. Traitement du texte. Arborescence de fichiers. Sécurité...
  10. #10

    Advanced Product Management

    3 Books

    Get The Art of Strategy, Product Discovery and Lean Product Management with a 20% discount.

Publish Early, Publish Often

  • Path
  • There are many paths, but the one you're on right now on Leanpub is:
  • › Object-design

Leanpub is copyright © 2010-2021 Ruboss Technology Corp. All rights reserved.