Question

我正面临着Rails中选择选项的问题。更改状态时，应该附加城市选项，但对我不起作用。请帮助我，这是怎么回事

这是我做的：在我的_form.html.erb文件中：

        <div class="form-group col-md-6">
          <!-- State -->
          <%= label_tag "Shop address" %>
          <%= select_tag :pstate, options_for_select(CS.states(:in).map { |c| [c[1], c[0]] }), class: "form-control", :required => true, :onchange => "stateChanged(event)" %>
        </div>

        <div class="form-group col-md-6">
          <!-- City -->
          <%= label_tag "Shop location" %>
          <%= select_tag :pcity, options_for_select([@pcities]), class: "form-control", :required => true %>
        </div>    
      </div>  

    <script>
       var stateChanged = function(e){
       $.ajax({
         url: "products/product_cities?state=" + e.target.value,
         type: "GET"
       })
     }
   </script>

在products_controller.rb文件中

   def product_cities
         @pcities = CS.get(:in, params[:state])
         puts @pcities.inspect
       end

在products_cities.js.erb文件中

    <%# // Find the state select box %>
 var city = document.getElementById("pcity");
 console.log(city);
 <%# // Clear the options in the select box %>
 while (city.firstChild) city.removeChild(city.firstChild);

 <%# // Add a placeholder %>
 var placeholder = document.createElement("option");
 placeholder.text = "Choose a city";
 placeholder.value = "";
 city.appendChild(placeholder);

 <%# // Add the cities %>
 <% @pcities.each do |c| %>
     city.options[city.options.length] = new Option('<%= c %>');
 <% end %>

您能帮我摆脱这个问题吗？

Answer 1

更改：

...options_for_select([@pcities])...

进入这一步（不要忘了对这两行都做！）：

...options_for_select([@pcities],@<<PUT YOUR MODEL HERE w/o BRACKETS>>.pcity)...

此最后一个可选参数的作用是设置下拉菜单（如果存在）的选定值。非常方便。

这是我自己的一个示例，其中使用了选择帮助器的所有参数：

<%= f.select :state, options_for_select(us_states, @user.state), {:include_blank => "Select a state"}, {:class => "form-control"} %>

:include_blank本质上是一个占位符。希望这会有所帮助！

下拉列表不使用Rails中的更新数据更新

1 个答案: