Rails keeping params DRY

Question

I have a model named "seo"

class Seo < ApplicationRecord
    belongs_to :seoable, polymorphic: true
    # more code
  end

Many models in my application has_one seo. For example

 class Post < ApplicationRecord
    has_one :seo, as: :seoable
    accepts_nested_attributes_for :seo, dependent: :destroy
    # more code
  end

My question is, what is the best way to keep params in my controllers dry. For example I have the following code in my posts_controller

def post_params
  params.require(:post).permit(seo_attributes: [:id, :title, :meta_description, :etc])
end

Every model will repeat the above. How do I keep this DRY?

Answer 1

I think this is an example where you could use a concern:

# in app/models/concern/seoable.rb
require 'active_support/concern'

module Seoable
  extend ActiveSupport::Concern
  included do
    has_one :seo, as: :seoable
    accepts_nested_attributes_for :seo, dependent: :destroy
  end
end

# in your models
class Post < ApplicationRecord
  include Seoable
end

And for the controllers, you could add a method into AplicationController that allows simplified the call:

# in the application_controller
def params_with_seo_attributes(namespace)
  params.require(namespace).permit(seo_attributes: [:id, :title, :meta_description, :etc])
end

# and use it in your controllers like this
def post_params
  params_with_seo_attributes(:post)
end