ActiveRecord::CallbacksГотовим правильно

Павел Габриель / @alovak

AR::Callbacks

before_create / save / update / validateafter_*

Что не так с AR::Callbacks?

“That’s a total of twelve callbacks,

which gives you immense power to react and prepare for each state

in the ActiveRecord life cycle.”

— active_record/callbacks.rb

“That’s Ruby, which gives you

immense power to do, you know,pretty much anything, ever”

— Ernie Miller

Google

“Are ActiveRecord Callbacks Any Good?”

“ActiveRecord Callbacks are Unreasonable”

“Rails, callbacks, workers, and the race you never expected to lose”

“ActiveRecord's Callbacks Ruined My Life”

В чем же проблема?

Проблема?

Single Responsibility Principle

“A class should do the smallest

possible useful thing; that is,it should have

a single responsibility.”

— Sandi Metz

SRP Violation

К лишнему весу ..

SRP Violation

К усложнению кода

SRP Violation

К сложным тестам

Невозможности повторного использования

И т.д.

Варианты решений

Вариант с Dependency Injection

Вариант с Service

Вариант с Events/Signals

ActiveSupport::Notifications

Wisper (gem)

• Минимизируйте зависимости с помощью Dependency Injection

• Объединяйте несколько моделей в Service

• Используйте Events/Signals

“Rails makes it natural and easy to

build large, well-designed OOP systems.”

— ????????

“Rails makes it natural and easy to

build large, well-designed OOP systems.”

— Nobody

Rails has no brain; use your own!

Спасибо!

alovak@gmail.com