Go Pro with POROs

Plain Old Ruby Objects (POROs) are having a moment. Maybe you’ve heard a whisper in the corner about the jack-of-all trades Service Object, or a glimmering echo of advocacy for non-database-backed domain models? Think you’re using them right? Afraid you’re using them wrong? Then this is the talk for you! We’re going to explore the wonderful world of “convention plus choose-your-own configuration” of Rails codebases and the shining role of POROs (with their ride or dies, the Module). Come hear about the diversity of design patterns out in the wild so you too can confidently tell your coworkers “let’s just use a PORO for that”.

Transcript

1. Go Pro with POROs Ifat Ribon Rocky Mountain Ruby 2023
2. ifat@launchpadlab.com @i_ribon9 inveterateliterate
3. ENCAPSULATION
4. CLARITY
5. SIMPLICITY
6. Services Virtual Domain Models Request & Presentation Objects API Wrappers Modules Common Ruby on Rails Design Patterns Database Wrappers
7. Database Wrappers 01
8. • Methods closely tied to the table and domain model it represents • Can be used for any database- backed model, in any schema • Classes as part of Object- Relational Mapping (ORM) framework • An interface for working with your database models in Ruby • Supports querying, relationships, and data integrity What are They? How are They Used?
10. Modules 02
11. • Model Concerns • Controller Concerns and View Helpers • Shared logic between objects • Calculators • Collection of related code • Cannot be instantiated • Can be used directly or to extend other bundles of code What are They? How are They Used?
15. Interlude
16. What is a PORO? A PORO is a “Plain Old Ruby Object”, a moniker used to distinguish any other Ruby class not backed by a database table (e.g., ActiveRecord classes)
17. POROs! Services API Wrappers Virtual Domain Models Request and Presentation Objects
18. Services 03
19. • Generally exposes only one public method • Often named as a “verb as a noun” or directly as a verb • Leverage attr_reader for the key attributes of the class • POROs that encapsulate business logic to perform calculations, transactions, or series of steps • Can leverage attr_* methods and expose public attributes • Can leverage inheritance What are They? How are They Used?
22. API Wrappers 04
23. • Reusable classes to interact with external APIs • Interfaces for making requests to the API • Abstractions for network request details What are They? How are They Used? • Methods for RESTful routes • Overwritable methods for adjusting header objects or payloads • Boilerplate code or helpers shared across subclasses
26. Virtual Domain Models 05
27. • Public methods for model attributes, CRUD actions, and memoized calculations • API results wrappers, memoized calculations, and interdependent associations What are They? How are They Used? • POROs to represent domain objects that aren’t database tables • Often used for transient data that will be immediately worked on and does not need to persist
31. Request & Presentation Objects 06
32. • Presenters, Decorators, and View Components • Form Objects • Serializers • Transformers What are They? How are They Used? • POROs that support the request, response, or presentation layers • Reduce controller, model, and view complexity • Support easier testing strategies for layers we otherwise don’t readily test
40. Resources • View Components • Draper • Decanter
41. Thank You! ifat@launchpadlab.com @i_ribon9 inveterateliterate