ruby-on-rails - Rails 设计多态 - 使用 Ajax 获取部分渲染

Question

我已经实现了来自 this answer 的多个模型的设计注册.这 tuts 得到参数 user_type从路径。
我想用 select user_type 改变这个.所以当我在 select_tag 上选择一个值时会得到一个参数 user_type .

我有一些代码看起来像:

路线.rb

   namespace :cp do
    devise_scope :user do
     match '/add_user' => 'registrations#new'
     match '/select/admin' => 'registrations#selectuser', :user => { :usertype => 'admin' }
     match '/select/player' => 'registrations#selectuser', :user => { :usertype => 'player' }
    end
   end

registrations_controller.rb

  def selectuser

    respond_to do |format|
      format.js
    end
  end

new.html.erb

<h2>Add User</h2>

<%= form_for(resource, :as => resource_name, :url => registration_path(resource_name)) do |f| %>
  <%= devise_error_messages! %>

  <div><%= f.label :username, "Username" %><br />
  <%= f.text_field :username %></div>

  <div><%= f.label :email, "Email" %><br />
  <%= f.email_field :email %></div>

  <div><%= f.label :password, "Password" %><br />

  <%= f.password_field :password %></div>

  <div><%= f.label :password_confirmation, "Password Confirmation" %><br />
  <%= f.password_field :password_confirmation %></div>

  <div><%= f.label :usertype, "Select User Type" %><br />
  <%= f.select(:usertype, options_for_select([['-- User Type --', nil], ['Admin', 'admin'], ['Player', 'player']], selected: '-- User Type --' )) %>
   </div> 

   <div id="selectuser">
   </div>
  <% end %>

  <div><%= f.submit "Submit" %></div>
<% end %>

<script type="text/javascript">
$("#user_usertype").on('change', function() {
   var s = $(this).val();
       $.ajax({
              type: 'GET',
              url: 'http://localhost:3000/cp/select/' + s,
              dataType: "HTML"
              });
});
</script>

选择user.js.erb

<%  params[:user][:usertype] ||= 'admin'

    if ["admin", "player"].include? params[:user][:usertype].downcase
      child_class_name = params[:user][:usertype].downcase.camelize
      usertype = params[:user][:usertype].downcase
    else
      child_class_name = "Admin"
      usertype = "admin"
    end


   nesteds = fields_for child_class_name.constantize.new do |rf|
     render :partial => child_class_name.underscore + '_fields', :locals => {:f => rf}
   end
%>
$("#selectuser").append("<%= j nesteds %>");

当我选择管理员值时，记录:

Started GET "/cp/select/admin" for 127.0.0.1 at 2013-10-21 17:00:04 +0700
Processing by Cp::RegistrationsController#selectuser as HTML
  Parameters: {"user"=>{"usertype"=>"admin"}}
  Rendered cp/registrations/_admin_fields.html.erb (4.0ms)
  Rendered cp/registrations/selectuser.js.erb (7.0ms)
Completed 200 OK in 22ms (Views: 22.0ms | ActiveRecord: 0.0ms)

但是 _admin_fields.html.erb未出现在 #selectuser

Answer 1

你在这里混淆了几件事。

您的路由定义了一个默认值

如果您需要从下拉列表中进行选择，则无需在此处定义默认值。它只是让事情复杂化

 match '/add_user' => 'registrations#new', :user => { :usertype => nil }
 match '/select/admin' => 'registrations#selectuser', :user => { :usertype => 'admin' }
 match '/select/player' => 'registrations#selectuser', :user => { :usertype => 'player' }

您没有使用正确的表单助手

您需要使用 f.select如果你想得到 params[:user][:usertype] 的输出.如果您的模型没有这样的属性，您可以将其添加为 attr_accessor到你的模型。

<%= label :usertype, "Select User Type" %><br />
<%= select_tag(:usertype, options_for_select([['-- User Type --', nil], ['Admin', 'admin'], ['Player', 'player']], selected: '-- User Type --' )) %>