Set Rails routing other than id

RailsでscaffoldするとURLの形式はexample.com/posts/:idになります。 However, there may be times when you do not want to use id for a parameter. 今回はexample.com/posts/:uuidの様な形式でidの代わりにuuidを設定してみました。

Add column

Add a uuid column when creating the table.

$ rails g scaffold post uuid:string body:text

class CreatePosts < ActiveRecord::Migration[6.0]
  def change
    create_table :posts do |t|
      t.string :uuid, null: false
      t.text :body

      t.timestamps
    end

    add_index :posts, :uuid
  end
end

$ rails db:migrate

Set up routing

config/routes.rb

resources :posts, param: :uuid

#When setting only the detail screen
# get '/posts/:uuid', to: 'posts#show'

set uuid

Add a process to set the uuid before saving the data.

app/models/application_record.rb

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  private

  #add to
  def set_uuid
    if self.has_attribute?(:uuid) && self.uuid.blank?
      self.uuid = SecureRandom.hex(10)
    end
  end
end

app/models/post.rb

class Post < ApplicationRecord
  #add to
  before_create :set_uuid
end

Fix controller

If you access the screen as it is, an error will occur, so fix the controller.

app/controllers/posts_controller.rb

def set_post
  @post = Post.find_by(uuid: params[:uuid])
end

これでexample.com/posts/:uuidの形式への設定ができました。