Question

我正在尝试按照Rails文档和Railscast＃88进行操作，但有3个模型。该页面将有3个下拉框用于State，County和＆amp;市。我有州＆gt;县与JQuery合作。但是当试图为城市建立 grouped_collecion_select 时，事情正在崩溃。

以下是3个型号：

service_area_state.rb

 class ServiceAreaState < ActiveRecord::Base
    has_many :service_area_counties
    default_scope -> { order(name: :asc) }
 end

service_area_county.rb

class ServiceAreaCounty < ActiveRecord::Base
    belongs_to :service_area_state
    default_scope -> { order(name: :asc) }
end

service_area_city.rb

class ServiceAreaCity < ActiveRecord::Base
    belongs_to :service_area_county
end

在我的控制器中，我有以下内容：

def index

    @states = ServiceAreaState.all
    @counties = ServiceAreaCounty.all
    @cities = ServiceAreaCity.all

end #index

在视图中我有：

index.html.erb

<div class="row">
<div class="field" id='state_div'>

    <%= label_tag :service_area_state_id, "State", id:"service_area_state" %> <br/>

**This works**
    <%= collection_select(:service_area_state, :id, @states, :id, :name, prompt: true ) %>

</div>

<div class="field" id='county_div'>
    <%= label_tag :service_area_county_id, "County" %><br>

**This works**
    <%= grouped_collection_select(:service_area_county, :service_area_county_id, @states, :service_area_counties, :name, :id, :name, prompt: true ) %>
</div>

<div class="field" id='city_div'>
    <%= label_tag :service_area_city_id, "City" %><br>

**This does not work**
    <%= grouped_collection_select(:service_area_city, :service_area_county_id, @counties, :service_area_cities, :name, :id, :name, prompt: true )   %>
</div>
</div>

我收到以下错误：

undefined method `service_area_cities' for #<ServiceAreaCounty:0x007fb5e7dac060>

在这一行：

<%= grouped_collection_select(:service_area_city, :service_area_county_id, @counties, :service_area_cities, :name, :id, :name, prompt: true )   %>

有人可以找到我出错的地方吗？

谢谢！

Answer 1

您需要将service_area_cities设置为ServiceAreaCounty模型中的关联（听起来像是一个has_many关联）：

class ServiceAreaCounty < ActiveRecord::Base
  belongs_to :service_area_state
  has_many :service_area_cities
  default_scope -> { order(name: :asc) }
end

Rails groups_collection_select有3个模型

1 个答案: