rails 5 fast_jsonapi oj serializer api action

json_response_example_for_so.rb

# frozen_string_literal: true

module JsonResponse
  extend ActiveSupport::Concern

  included do
  end

  module ClassMethods
    def api_action action_name, &block
      define_method action_name do
        json_response block.call
      end
    end
  end

  def json_response(resource, root = nil, status = :ok)
    if !request.get? && resource.respond_to?(:errors) && resource.errors.any?
      status = :bad_request
    end

    if resource.is_a?(Hash) || resource.is_a?(Array)
      render json: resource, status: status
    else
      render json: fast_json_for(resource, root), status: status
    end
  end

  def fast_json_for(resource, root=nil)
    serializer_klass = "#{controller_name.classify}Serializer".constantize
    data = serializer_klass.new(resource).to_h
    return data unless root
    { root => data }
  end
end

# todos_controller.rb
# frozen_string_literal: true

class Api::V1::TodosController < Api::V1::ApplicationController
  include JsonResponse
  # .... some code here
  
  api_action(:todo_ids){ @task.todo_ids }

  api_action :index do
    if parsed_validated_ids.present?
      @todos = @task.todos.where(id: parsed_validated_ids)
    else
      @todos = @task.todos.page(page).per(per_page)
    end

    list
  end

  api_action(:show){ @todo }

  api_action(:update){ @todo.update_attrs(update_params, current_user.id) }
  
  .....