我正在尝试在我的 rails 应用程序中实现设计，并在我的 _header.html.erb 部分中出现语法错误：
<header class="navbar navbar-fixed-top">
<div class="navbar-inner">
<div class="container">
<%= link_to "OpenDeals", root_path, id: "logo" %>
<nav>
<ul class="nav pull-right">
<li><%= link_to "Home", root_path %></li>
<li><%= link_to "Contact", contact_path %></li>
<li>
<%= if user_signed_in? %>
Logged in as <strong><%= current.user.email %></strong>.
<%= link_to 'Edit profile', edit_user_registration_path %>
<%= link_to 'Logout', destroy_user_session_path, method: :delete %>
<%= else %>
<%= link_to 'Sign up', new_user_registration_path %> |
<%= link_to 'Login', new_user_ssession_path %>
<%= end %>
</li>
</ul>
</nav>
</div>
我收到的错误消息是：
/Users/adnankhan/code/opendeals/app/views/layouts/_header.html.erb:10：语法错误，意外')'，期待keyword_then或';' 或 '\n' ....append= ( if user_signed_in? );@output_buffer.safe_concat(' ... ^ /Users/adnankhan/code/opendeals/app/views/layouts/_header.html.erb:14:语法错误，意外的keyword_else ...);@output_buffer.append= ( else );@output_buffer.safe_concat ... ... ^ /Users/adnankhan/code/opendeals/app/views/layouts/_header.html.erb :17: 语法错误，意外的keyword_end ...');@output_buffer.append= (end);@output_buffer.safe_concat... ... ^ /Users/adnankhan/code/opendeals/app/views/layouts/_header .html.erb:23：语法错误，意外的keyword_ensure，期待')'
非常感谢任何帮助。