javascript - 嵌套表单 rails 中的动态选择

Question

js 如何获取下拉列表中选定的值并将其传递给 Controller ​​，以便它返回另一个下拉列表的名称列表？

到目前为止我已经做了什么:沙门氏菌.js

$(function () {
   $('body').on('change', "#mode_change", function () {
        var selectedText = $(this).find("option:selected").text();
        var selectedValue = $(this).val();
        if (selectedText) {
          $.get('/salmonellas/find_stages?mode_title='+ selectedText, function(selectedText) {                
            return $(selectedText).html();
          });
        }
    });
});

沙门氏菌/form.html.erb

<div class="process_salmonellas">
    <% f.simple_fields_for :process_salmonellas do |process_salmonella| %>
        <%= render 'process_salmonella_fields', :f => process_salmonella %>
    <% end %>
</div>

沙门氏菌/_process_salmonella_fields.html.erb

<div class="mode_change" id="mode_change">
    <%= f.collection_select :title, Mode.order(:name), :id, :name, class: 'mode_change', id:'mode_change', include_blank: true, "data-content": :mode_id%>
</div>
<h4>Stage</h4>
<div class="stage">
    <% f.simple_fields_for :stages do |stage| %>
        <%= render 'stage_fields', :f => stage %>
    <% end %>
</div>

沙门氏菌/_stage_fields.html.erb

<div class="form-inputs">
    <%= f.grouped_collection_select :title, Mode.order(:name), :steps, :name, :id, :name, class: "step_selection" %>
</div>

沙门氏菌_controller.rb

def find_stages
    @mode = Mode.where("name = ?", params[:mode_title])
    @steps = @mode.steps
end

正在寻找其他模型，为什么字段必须预先注册。我用茧让它嵌套。

正在更新

沙门氏菌/_process_salmonella_fields.html.erb

<div class="form-inputs">
    <%= f.collection_select :title, Mode.order(:name), :id, :name, class: 'mode_change', id:'mode_change', include_blank: true, "data-content": :mode_id%>
</div>
<h4>Stage</h4>
<div class="stage">
    <% f.simple_fields_for :stages do |stage| %>
        <%= render 'stage_fields', :f => stage %>
    <% end %>
</div>

更新2

沙门氏菌/_process_salmonella_fields.html.erb

<div class="form-inputs">
    <%= f.collection_select :title, Mode.order(:name), :id, :name, id:'mode_change', include_blank: true %>
</div>

沙门氏菌.js

$(function () {
   $('body').on('change', ".mode_change", function () {
        var selectedText = $(this).find("option:selected").text();
        var selectedValue = $(this).val();
        if (selectedText) {
          $.get('/salmonellas/find_stages?mode_title='+ selectedText, function(selectedText) {                
            return $(selectedText).html();
          });
        }
    });
});

更新3

沙门氏菌.js

 $(function () {
   $(document).on('change', "#mode_change", function () {
        var selectedText = $(this).find("option:selected").text();
        var selectedValue = $(this).val();
        alert("Selected Text: " + selectedText);
    });
});

Answer 1

ID 在您的 DOM 上必须是唯一的。您正在为 div 和 select 标记复制它们。首先更改它们并使用它来获取所选选项的值

$(document).on('change', ".mode_change", function () {
    var selectedText = $(this).find("option:selected").text();
    var selectedValue = $(this).val();
      ...