The Sweet Spot
On software, engineering leadership, and anything shiny.

Decomposing Fat Models

Heard an awesome Ruby Rogues podcast recently: “Decomposing Fat Models”.

Essentially, they’re talking through Bryan Helmkamp’s Code Climate blog entry “7 ways to decompose fat ActiveRecord models”, which sums up a few strategies that mainly involve extracting objects from your existing code, value, service, policy, decorator objects and the like. Give the entry a read-through, it’s opened my eyes a lot to rethinking my architecture of my Rails models.

A few interesting thoughts that came up in the podcast:

  • The “Skinny Controller, Fat Model” mantra has hurt the Rails community because we start getting these bloated AR classes. “‘fat-‘ anything is bad” one of the hosts mentions in the blog. The smaller your models, the more manageable, readable and testable they become.

  • Rubyists don’t like the term “Factory”, even though in Helmkamp’s opinion, Ruby classes are factories. “We call them “builders”” one of the hosts jokes.

  • The Open/Closed Principle as applied to Ruby: using delegators, decorators.