Ajax action won't reflect on appearance but the value. Why?

问题

I'm using Rails3. Now trying to implement follow button in index.html.erb just like twitter.
It shows member list and their follow buttons.
It looks okay but if I press any of those follow button, appearance doesn't change.
It should changes follow to un-follow right away.
I have no idea why it does. But if I reload the page, it shows correct status.

follows_controller.rb

class FollowsController < ApplicationController

  def create
    @user = User.find(params[:user_id])
    current_user.follow(@user)
    respond_to do |format|
      format.js {render :action=>"create.js"}
      end
  end

  def destroy
    @user = User.find(params[:user_id])
    current_user.stop_following(@user)
    respond_to do |format|
      format.js {render :action=>"destroy.js"}
  end
end

end

views/users/_follow_user.html.erb

<% unless user == current_user %>
    <% if current_user.following?(user) %>
        <%= button_to("Un-Follow", user_follow_path(user.to_param, current_user.get_follow(user).id), 
        :method => :delete, 
        :remote => true, 
        :class => 'btn') %>
    <% else %>
        <%= button_to("Follow", user_follows_path(user.to_param), 
        :remote => true, 
        :class => 'btn btn-primary') %>
    <% end %>
<% end %>

views/users/create.js.erb

$('.follow_user[data-user-id="<%=@user.id%>"]').html('<%= escape_javascript(render :partial => "follow_user", :locals => {:user => @user}) %>');
#jQuery

views/users/destroy.js.erb

$('.follow_user[data-user-id="<%=@user.id%>"]').html('<%= escape_javascript(render :partial => "follow_user", :locals => {:user => @user}) %>');
#jQuery

views/users/index.html.erb

<%- model_class = User.new.class -%>
<div class="page-header">
  <h1><%=t '.title', :default => model_class.model_name.human.pluralize %></h1>
</div>
  <% @from %>
  <h3>tag cloud</h3>
  <% tag_cloud(@tags, %w(css1 css2 css3 css4)) do |tag, css_class| %>
    <%= link_to tag.name, {:action=>'index', :tag=>tag.name}, :class => css_class%>
  <% end %> 


<%= paginate @users %>

<table class="table table-condensed">
  <thead></thead>
    <tbody>
    <% @users.each do |user| %>  
      <div class="memberListBox">
        <div class="memberList">
            <p class="name"><span><%= user.user_profile.nickname %></span>(<%= user.user_profile.age %>)</p>
            <p class="size"><%= user.username %></p>
            <p class="img">
            <% if user.user_profile.user_avatar? %>
            <%= image_tag(user.user_profile.user_avatar.url(:thumb),:height => 100, :width => 100, :class => 'img-polaroid' ) %>
            <% else %>
            <%= image_tag('nophoto.gif',:height => 100, :width => 100, :class => 'img-polaroid' ) %>
            <% end %>
            </p>
            <div class="introduction">
                <%= user.user_profile.introduction %>
            </div>

<% if user_signed_in? && current_user!=user %>          
  <div id="follow_user">
    <%= render :partial => "follow_user", :locals => {:user => user} %>
  </div>
<% end %>

  <%= link_to sanitize('<i class="icon-pencil icon-white"></i> ') + 'Message', new_messages_path(user.username), :class => 'btn btn-primary'  %>


                <%= link_to sanitize('<i class="icon-user icon-white"></i> ') + 'Profile', show_user_path(:username => user.username, :breadcrumb => @from), :class => 'btn btn-info' %>              

        </div>
    </div>
   <% end %>
  </tbody>  
</table>

response content

$('#follow_user').html(' <form action=\"/users/1/follows\" class=\"button_to\" data-remote=\"true\" method=\"post\"><div><input class=\"btn btn-primary\" type=\"submit\" value=\"Follow\" /><input name=\"authenticity_token\" type=\"hidden\" value=\"G/taOUeWy2gumhWUi10cPvECAmYLQdhQ2/eGGMJwvPE=\" /><\/div><\/form>\n');

回答1:

Add the user id to the attribute data-user-id and add the class follow_user

<div class="follow_user" data-user-id="<%= user.id %>">
  <%= render :partial => "follow_user", :locals => {:user => user} %>
</div>

来源：https://stackoverflow.com/questions/13898891/ajax-action-wont-reflect-on-appearance-but-the-value-why