ActiveAdmin:按子协会的属性排序

Question

我有这些对象:

class District < ActiveRecord::Base
  belongs_to :city
end
class City < ActiveRecord::Base
  has_many :districts
end

我想做的(迄今为止无法做到)是:City在District索引中有一列,该列应该是可排序的City.name.

在没有崩溃ActiveAdmin的情况下我能做的最近的事情是:

index do
  column City.human_name(:count => :other), :city, :sortable => :city_id
end

这当然不够好; 我不想对外键的整数值进行排序.

尝试过的东西:sortable => 'city.name',给出了一个错误.甚至试图像你在"纯粹的"Rails上那样做 - :joins => :cities, :sortable => 'city.name'- 没有运气.尝试了一堆其他愚蠢的东西,生气了,决定谦卑地寻求帮助.

谁能指出我正确的方向？谢谢你的时间.

Answer 1

那也应该做的工作:

index do
  column City.model_name.human, :city, :sortable => 'cities.name'
end

controller do
  def scoped_collection
    end_of_association_chain.includes(:city)
  end
end

Answer 2

试试这个......这会有所帮助....

index do
  column :city, :sortable => :"cities.name" do |district|
    district.city.human_name(:count => :other) if district.city.present?
  end
end

controller do
  def scoped_collection
    District.includes(:city)
  end
end

Answer 3

非常简单且可读的解决方案：

index do
  column :city, sortable: "cities.name"
end

controller do
  def scoped_collection
    # join cities
    super.includes :city
  end
end