Off the Rails: Patterns for fixing fat models, out-of-controllers, and other Rails problems

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Off the Rails Patterns for ﬁxing fat models, out-of-controllers, and other Rails problems

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What I’m about to tell you is wrong.

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YMMV

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MVC

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View Controller Model

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3 Tier Architecture

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Business Logic Presentation Data

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Business Logic Presentation Data

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Business Logic Presentation Data View Controller Model

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Business Logic Presentation Data View Controller Model

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View Controller Model Business Logic Presentation Data

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View Controller Model

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Model Service View Controller

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Business Logic Presentation Data

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Business Logic Presentation Data

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Business Logic Presentation Data Service

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Controller Rule of Thumb A Controller May Contain: • Public REST methods • Private before_action setters • Private strong params method

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Models

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Business Logic Presentation Data View Controller Model

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Business Logic Presentation Data View Controller Model

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Business Logic Presentation Data View Controller Model Repository

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Business Logic Presentation Data View Controller Validator Model

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–Sandi Metz “duplication is far cheaper than the wrong abstraction”

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YAGNI

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Bonus Tip

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Thanks for Listening Alexander Clark atheclark alexander-clark.com alexander-clark

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Further reading • https://codeclimate.com/blog/7-ways-to-decompose-fat- activerecord-models/ • Patterns of Enterprise Application Architecture (Fowler) • Domain Driven Design (Evans) • All the Little Things (Metz) https://www.youtube.com/ watch?v=8bZh5LMaSmE • Ruby Object Mapper https://rom-rb.org/

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Questions?