javascript - Rails 4 - 依赖选择导致错误的急切加载(Rails4/Active Admin)

Question

我有一个带有依赖选择的事件面板，即第一个下拉选择中的选择会影响第二个下拉选择中显示的内容。

几个月前一切都运行良好，但我昨天才意识到它不再工作了。

我设法找到导致错误的原因:如果我删除预先加载(“include”)，它会再次运行。

不工作:(当前版本):

@deal_subsectors = DealSector.find(params[:deal_sector_id],
   include: :deal_subsectors).dealsubsectors

我收到此错误(来自 chrome 开发工具的控制台)

GET http://localhost:3000/admin/deals/deal_subsectors_by_deal_sector?deal_sector_id=2 404 (Not Found)    
send @ jquery.js?body=1:9660    
jQuery.extend.ajax @ jquery.js?body=1:9211    
jQuery.(anonymous function) @ jquery.js?body=1:9357    
jQuery.extend.getJSON @ jquery.js?body=1:9340    
update_deal_subsector @ active_admin.js?body=1:19    
(anonymous function) @ active_admin.js?body=1:12    
jQuery.event.dispatch @ jquery.js?body=1:4666    
elemData.handle @ jquery.js?body=1:4334    
ListPicker._handleMouseUp @ about:blank:632

工作，当我删除“include”/eager loading 时:

@deal_subsectors = DealSector.find(params[:deal_sector_id]).deal_subsectors

在那种情况下它工作得很好。

但我真的很想加载交易子行业，所以我想知道是什么导致了这个错误，自从它开始工作以来发生了什么变化。我有一些假设，但找不到罪魁祸首。

• Rails 4 是否改变了我应该使用 find(params[:id]..) 的方式或者我应该使用预加载的方式

• active Admin 是否改变了它处理预先加载的方式:也许它只适用于索引而不适用于编辑页面......

• 现在 Rails 4 上的 turbolinks 是否改变了我必须预先加载的方式？

代码如下:

- 在 Active Admin 上

ActiveAdmin.register Deal do

# controller for the multi-select sector/subsector in the form
# does 2 things at same time: creates method and automatically defines the route of the method defined in controller
    if params[:deal_sector_id] # pass the id
      @deal_subsectors = DealSector.find(params[:deal_sector_id], include: :deal_subsectors).dealsubsectors
    else
      @deal_subsectors = []
    end

    render json: @deal_subsectors
  end   

end

- 带有 2 个依赖选择的表单

form do |f|

f.inputs "Client" do


      f.input :deal_sector_id,
        :label      => "Select industry:",
        :as         => :select,
        :prompt     => true,
        :collection => DealSector.order("name").all.to_a
      f.input :deal_subsector_id,
        :label      => "Select subindustry:",
        :as         => :select,
        :prompt     => true,
        :collection => DealSubsector.order("name").all.to_a        
    end

end

- 支持它的 javascript:

        // for edit page
        var deal_subsector = { };

       $(document).ready(function() {
         $('#deal_deal_sector_id').change(function() {
            update_deal_subsector();
         });
       });

       function update_deal_subsector() {
           deal_sector_id = $('#deal_deal_sector_id').val(); //get the value of sector id
           url = '/admin/deals/deal_subsectors_by_deal_sector?deal_sector_id=' + deal_sector_id; //make a query to the url passing the deal sector id as a parameter
          $.getJSON(url, function(deal_subsectors) {
              console.log(deal_subsectors);
                  $('#deal_deal_subsector_id').html("") //just blanks the id, blank it before populating it again if sector changes
              for( i = 0; i < deal_subsectors.length; i++) {
                 console.log(deal_subsectors[i]);
                 $('#deal_deal_subsector_id').append("<option value=" + deal_subsectors[i].id + ">" + deal_subsectors[i].name + "</option>")
      };
    }); //pass the url and function to get subsector ids and all we get is assigned to the variable subsector_id
  };

          // for index page (filters)
          $(document).ready(function() {
              $('#q_deal_sector_id').change(function() {
                 update_deal_subsector_filter();
              });
              });

          function update_deal_subsector_filter() {
               deal_sector_id = $('#q_deal_sector_id').val(); //get the value of sector id
               url = '/admin/deals/deal_subsectors_by_deal_sector?deal_sector_id=' + deal_sector_id; //make a query to the url passing the deal sector id as a parameter
               $.getJSON(url, function(deal_subsectors) {
                      console.log(deal_subsectors);
                $('#q_deal_subsector_id').html("") //just blanks the id, blank it before populating it again if sector changes
                 for( i = 0; i < deal_subsectors.length; i++) {
                     console.log(deal_subsectors[i]);
                     $('#q_deal_subsector_id').append("<option value=" + deal_subsectors[i].id + ">" + deal_subsectors[i].name + "</option>")
      };
    }); //pass the url and function to get subsector ids and all we get is assigned to the variable subsector_id
        };

添加文件

class DealSector < ActiveRecord::Base
  has_many    :deal_subsectors
end

class DealSubsector < ActiveRecord::Base    
  belongs_to  :deal_sector,   :foreign_key => 'deal_sector_id'
end

Answer 1

当您调用 ActiveRecord::find 时 – 这意味着您希望从数据库中获得一个单一的模型。然后，您引用此模型并调用 dealsubsectors – 我假设它与您的模型有 has_many 关系。它将产生 2 个查询:第一个是获取原始 DealSelector，第二个是所有相关的 DealSubsectors。没有什么可以优化的(除非您 dealsubsectors 是模型中的自定义方法，而不是关系)。

如果您发现某些东西通过查询访问了您的数据库——您必须在另一个地方查看。比方说，您的表格——您是否在每个表格中只显示一个客户？如果不是，它将为每个新客户迭代并再次获取所有 DealSector 和 DealSubsector。尝试提供更多代码。