The StoreModel Ruby gem allows you to wrap JSON-backed database columns with ActiveModel-like classes.
- Powered with Attributes API. You can use a number of familiar types or write your own.
- Works like ActiveModel. Validations, enums and nested attributes work very similar to APIs provided by Rails.
- Follows single responsibility principle. Keeps the logic around the data stored in a JSON column separated from the model.
- Born in production.
class Configuration include StoreModel::Model attribute :model, :string enum :status, %i[active archived], default: :active validates :model, :status, presence: true end class Product < ApplicationRecord attribute :configuration, Configuration.to_type end
Why should I wrap my JSON columns?
Imagine that you have a model
Product with a
jsonb column called
configuration. This is how you likely gonna work with this column:
product = Product.find(params[:id]) if product.configuration["model"] == "spaceship" product.configuration["color"] = "red" end product.save
This approach works fine when you don’t have a lot of keys with logic around them and just read the data. However, when you start working with that data more intensively—you may find the code a bit verbose and error-prone.
For instance, try to find a way to validate
:model value to be required. Despite of the fact, that you’ll have to write this validation by hand, it violates single-repsponsibility principle: why parent model (
Product) should know about the logic related to a child (
Read more about the motivation: