Playing with ActiveModelSerializers to generate a redux friendly data structure.

picking_serializer.rb

class PickingSerializer < ActiveModel::Serializer

  attribute :data do
    {
      result: object.id,
      entities: {
        orders: { object.id => OrderSerializer.new(object) },
        line_items: object.line_items.each_with_object({}) do |line_item, h|
          h[line_item.id] = LineItemSerializer.new(line_item)
        end
      }
    }
  end

  attribute :errors do
    {
      orders: { object.id => object.errors },
      line_items: object.line_items.each_with_object({}) do |line_item, h|
        h[line_item.id] = line_item.errors
      end
    }
  end

  attribute :meta do
    {}
  end

  class OrderSerializer < ActiveModel::Serializer
    attributes :id, :uuid, :total_products, :total_price_excl_delivery, :state,
               :delivery_price_pence, :post_code, :store, :slot, :created_at

    attribute :line_items do
      object.line_items.pluck(:id)
    end
  end

  class LineItemSerializer < ::LineItemSerializer
    attributes :id
  end

end