ruby-on-rails – 无法让Ajax在follow / unfollow按钮上工作 –

借助Ajax的神奇之处：当我点击“关注”按钮时,它应该更新用户在个人资料页面中看到的关注者数量,而无需刷新页面.但是,我的示例应用程序中没有发生这种情况.

发生的事情是,“跟随”按钮,当点击时,变为“取消关注”,因为它应该但是,跟随者的数量保持不变,直到我点击网络浏览器中的刷新按钮(在FF和IE中测试).我正在关注Michael Hartl的railstutorial.org,使用Rails 4和Ruby 2.0.0p195.

这是我从FireFox获得的控制台消息：

传递给getElementById()的空字符串.

这是我下面的代码,视图中的“跟随”按钮对应于关系控制器中的操作,它们应该命中create.js.erb和destroy.js.erb部分.

-CONTROLLER-
relationships_controller.rb

def create
    @user = User.find(params[:relationship][:followed_id])
    current_user.follow!(@user)
    # redirect_to @user
    respond_to do |format|
      format.html { redirect_to @user }
      format.js
    end
  end

def destroy
  @user = Relationship.find(params[:id]).followed
  current_user.unfollow!(@user)
  # redirect_to @user 
  respond_to do |format|
    format.html { redirect_to @user }
    format.js
  end
end

-JAVASCRIPT-
_create.js.erb：

$("#follow_form").html("<%= escape_javascript(render('users/unfollow')) %>");
 $("#followers").html('<%= @user.followers.count %>');

_destroy.js.erb：

$("#follow_form").html("<%= escape_javascript(render('users/follow')) %>");
 $("#followers").html('<%= @user.followers.count %>');

-VIEWS-是follow_form,带有_follow.html.erb和_unfollow.html.erb.

_follow_form.html.erb

<% unless current_user?(@user) %>
 <div id="follow_form">
    <% if current_user.following?(@user) %>
        <%= render 'unfollow' %>
    <% else %>
        <%= render 'follow' %>
    <% end %>
 </div>
 <% end %>

_follow.html.erb：

<%= form_for(current_user.relationships.build(followed_id: @user.id),remote: true) do |f| %>
    <div><%= f.hidden_field :followed_id %></div>
    <%= f.submit "Follow",class: "btn btn-large btn-primary" %>
 <% end %>

_unfollow.html.erb

<%= form_for(current_user.relationships.find_by(followed_id: @user),html: { method: :delete },remote: true) do |f| %>
   <%= f.submit "Unfollow",class: "btn btn-large" %>
<% end %>

注意 – 我在开发时使用postgreSQL而不是在railstutorial中使用的SQLlite.

编辑回应：
_stats.html.erb

<% @user = @user || current_user %>

 <div class="stats">
    <a href="<%= following_user_path(@user) %>">
        <strong id="following" class="stat">
            <%= @user.followed_users.count %>
        </strong>
        following
    </a>

    <a href="<%= followers_user_path(@user) %>">
        <strong id="following" class="stat">
            <%= @user.followers.count %>
        </strong>
        followers
    </a>
 </div>