rails 4 bootstrap 3 collapsable navbar

Question

Sorry for the newbie question, but can anyone see what I'm doing wrong? I followed the directions on the bootstrap website, and am unable to create a collapsing navbar in my web app. The list items under the ="nav pull-right" won't collapse when I decrease the width of the window. I think this maybe because I don't have a collapse plugin in my bootstrap.js. Could that be the issue?

<%= link_to "Catalyst", users_path, class: "brand" %>

<header class="navbar navbar-fixed-top navbar-inverse">
  <div class="navbar-inner">
    <div class="container">

      <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </a>
      <%= link_to "Webapp", users_path, class: "brand" %>
      <div class="nav-collapse collapse">
        <ul class="nav pull-right">
          <li><%= link_to current_user.full_name, current_user %></li>
          <li id="fat-menu" class="dropdown">
            <a href="#" class="dropdown-toggle" data-toggle="dropdown">
            Mailbox 
              <% if unread_count > 0 %>
                (<%= unread_count %>)
              <% end %>
              <b class="caret"></b>
            </a>
            <ul class="dropdown-menu">
              <li><%= link_to "Received", messages_path %></li>
              <li><%= link_to "Sent", sent_messages_path %></li>
            </ul>
          </li>
          <li><%= link_to "Sign out", destroy_user_session_path, :method => :delete %></li>
        </ul>
      </div>
    </div>
  </div>
</header>

Answer 1

将<div class="navbar-collapse collapse"> <div class="nav-collapse collapse">更改为<div class="navbar-collapse collapse">