Rails 3.1 multiple objects on one form

I've checked out a lot of questions for putting multiple objects on one form, but they seem to be out of date.

开发者_运维技巧I have a bunch of user objects:

  def index
    @users = User.all
    @user = current_user
  end

that I need to edit in a form. They all have roles which will be edited on the form. The form is rendered in a partial, and nothing shows up, just 'admin form' plaintext.

users/_admin.html.erb
admin form
<% form_for "user[]", :url => users_path do |f| %>
<ul>
  <li class="layout">
    <div class="header"><h2>Users</h2></div>
    <table>
      <thead>
          ...
      </thead>
      <tbody>
        <% @users.each do |user| %>
          <% puts "USER #{user}" %>
            <tr>
              <td><%= f.check_box(:editor) %></td>
              <td><%= f.check_box(:admin) %></td>
              <td><%= user.first_name %> <%= user.last_name %></td>
              <td><%= user.email %></td>
            </tr>
        <% end %>
      </tbody>
    </table>
  </li>
</ul>
<%= submit_tag "Save"%>
<% end %>

Just the plaintext is rendered, but no form. Any ideas on how to fix it? I've tried the suggestions in these posts: one two three, but they're out of date.

Thank you.

---

You need to use <%= .. %> in Rails 3.1:

<%= form_for "user[]", :url => users_path do |f| %>