我有一个带有从属下拉菜单的活动面板，即第一个下拉菜单的选择会影响第二个下拉菜单的显示内容。
几个月前一切都运行得非常完美，但我昨天才意识到它不再工作。
我找到了造成错误的原因：如果我移除贪婪加载（"include"），那么它就又可以工作了。 当前版本无法正常工作：
我从 Chrome 开发工具的控制台得到了以下错误信息：
几个月前一切都运行得非常完美，但我昨天才意识到它不再工作。
我找到了造成错误的原因：如果我移除贪婪加载（"include"），那么它就又可以工作了。 当前版本无法正常工作：
@deal_subsectors = DealSector.find(params[:deal_sector_id],
include: :deal_subsectors).dealsubsectors
我从 Chrome 开发工具的控制台得到了以下错误信息：
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
当我删除“include” / 急切加载时，工作原理如下：
@deal_subsectors = DealSector.find(params[:deal_sector_id]).deal_subsectors
在这种情况下，它完美地运作。
但我真的想要急切地加载交易子行业，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是否改变了我应该如何使用find(params[:id]..)或我应该如何使用eager loading的方式
active Admin是否改变了它处理eager loading的方式：也许它只在索引页面上工作，而不是在编辑页面上...
turbolinks现在在Rails 4上是否改变了我必须急切加载的方式？
以下是代码：
- 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个依赖选择器的表单
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
- 驱动它的JavaScript代码：
// 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
};
新增文件
class DealSector < ActiveRecord::Base
has_many :deal_subsectors
end
class DealSubsector < ActiveRecord::Base
belongs_to :deal_sector, :foreign_key => 'deal_sector_id'
end
DealSector.find(params[:deal_sector_id]).deal_subsectors- 您可以从控制台（rails c）运行它并查看查询。它将触发2个查询：查找DealSector和获取DealSubsectors。您必须考虑其他加载某些模型的地方 - 例如在视图中。 - shlajin