Rails Writing Affordances FAQs

Question 1

When is a model considered a candidate for this refactoring?

Accepted Answer

A model is a candidate if it has 3+ methods sharing a prefix, coordinates multiple associations simultaneously, or contains mixed conceptual domains that make the API confusing.

Question 2

Can I use Affordances for single-method extractions?

Accepted Answer

No, the pattern specifically requires a minimum of 3 related methods to avoid over-engineering; single methods should remain as plain methods or association extensions.

Question 3

Does this skill help with testing?

Accepted Answer

Yes, by extracting logic into POROs with the parent model as the only dependency, it makes unit testing domain logic much simpler and faster compared to testing fat ActiveRecord models.

Question 4

What is an Affordance in the context of Ruby on Rails?

Accepted Answer

An Affordance is a PORO (Plain Old Ruby Object) wrapper that groups 3 or more related operations around a specific noun or concept, providing a cleaner API than traditional model methods.

Question 5

How does this differ from a Rails Concern?

Accepted Answer

Concerns are best for infrastructure, callbacks, and validations that Rails calls implicitly. Affordances are for explicit operations and domain logic that the developer calls directly.

Rails Writing Affordances

About

Key Features

Use Cases

Rails Writing Affordances

About

Key Features

Use Cases