tracks/app/views/login/login.html.erb

<% auth_schemes = Tracks::Config.auth_schemes
   show_database_form = auth_schemes.include?('database') || auth_schemes.include?('ldap')
   show_openid_form = auth_schemes.include?('open_id')
   show_cas_form = auth_schemes.include?('cas')
-%>

<div title="<%= t('login.account_login') %>" id="loginform" class="form">

  <%= render_flash %>

  <h3><%= t('login.please_login') %>:</h3>
<% if show_database_form %>
  <div id="database_auth_form" style="display:<%=(@prefered_auth.eql?('database')) ? "block" : "none"%>">
      <% form_tag :action=> 'login' do %>
        <table>
          <tr>
            <td><label for="user_login"><%= User.human_attribute_name('login') %>:</label></td>
            <td><input type="text" name="user_login" id="user_login" value="" class="login_text" /></td>
          </tr>
          <tr> 
            <td><label for="user_password"><%= User.human_attribute_name('password') %>:</label></td>
            <td><input type="password" name="user_password" id="user_password" class="login_text" /></td>
          </tr>
         <tr> 
            <td><label for="user_noexpiry"><%= t('login.user_no_expiry') %>:</label></td>
            <td><input type="checkbox" name="user_noexpiry" id="user_noexpiry" checked  /></td>
          </tr>
          <tr> 
            <td></td>
            <td><input type="submit" name="login" value="<%= t('login.sign_in') %> &#187;" class="primary" /></td>
          </tr>
        </table>
      <% end %>
  </div>
<% end %>

<% if show_openid_form %>
  <div id="openid_auth_form" style="display:<%=(@prefered_auth.eql?('openid')) ? "block" : "none"%>">
    <% form_tag :action=> 'login' do %>
      <table>
        <tr>
          <td><label for="openid_url"><%= User.human_attribute_name('open_id_url') %>:</label></td>
          <td><input type="text" name="openid_url" id="openid_url" value="<%= @openid_url %>" class="login_text open_id" /></td>
        </tr>
       <tr> 
          <td><label for="user_noexpiry"><%= t('login.user_no_expiry') %>:</label></td>
          <td><input type="checkbox" name="user_noexpiry" id="user_noexpiry" checked  /></td>
        </tr>
        <tr> 
          <td></td>
          <td><input type="submit" name="login" value="<%= t('login.sign_in') %> &#187;" class="primary" /></td>
        </tr>
      </table>
    <% end %>
  </div>
 <% end %>

<% if show_cas_form %>
  <div id="cas_auth_form" style="display:<%=(@prefered_auth.eql?('cas')) ? "block" : "none"%>">
      <table>
        <tr>
          <td>	
			<% if @username && @user%>
			  <p><%= t('login.cas_logged_in_greeting', :username => @username) %></p>
			<% elsif @username %>
			  <p><%= t('login.cas_no_user_found', :username => @username) %>
                <%if SITE_CONFIG['open_signups']%>
                   <%= t('login.cas_create_account', :signup_link => link_to(t('login.cas_signup_link'), signup_url)) %>
                <%end%>
              </p>
			<% else %>
			  <p><%= link_to(t('login.cas_login'), login_cas_url) %>  </p>
			<% end %>
			</td>
        </tr>
      </table>
  </div>
 <% end %>
 
</div>
<% if show_openid_form %><p id="alternate_auth_openid" class="alternate_auth"><%= t('login.option_separator') %> <a href="#" onclick="Login.showOpenid();return false;"><%= t('login.login_with_openid') %></a></p><% end %>
<% if show_database_form %><p id="alternate_auth_database" class="alternate_auth"><%= t('login.option_separator') %> <a href="#" onclick="Login.showDatabase();return false;"><%= t('login.login_standard') %></a></p><% end %>
<% if show_cas_form %><p id="alternate_auth_cas" class="alternate_auth"><%= t('login.option_separator') %> <a href="#" onclick="Login.showCAS();return false;"><%= t('login.login_cas')%></a></p><% end %>

<script type="text/javascript">
function showPreferredAuth() {
  var preferredAuth = $.cookie('preferred_auth');
  var casEnabled = <%= show_cas_form ? 'true' : 'false' %>;
  var databaseEnabled = <%= show_database_form ? 'true' : 'false' %>;
  var openidEnabled = <%= show_openid_form ? 'true' : 'false' %>;
	if (preferredAuth && preferredAuth == 'openid' && openidEnabled) {
	  Login.showOpenid();
	}
	else if (preferredAuth && preferredAuth == 'database' && databaseEnabled)  {
	  Login.showDatabase();
	}
	else if (preferredAuth && preferredAuth == 'cas' && casEnabled)  {
	  Login.showCAS();
	}
}
$(document).ready(showPreferredAuth);

var Login = {
    showOpenid: function() {
        $('#database_auth_form').hide();
        $('#openid_auth_form').show();
        $('#alternate_auth_openid').hide();
        $('#alternate_auth_database').show();  ;
        $('#alternate_auth_cas').show();
        $('#openid_url').focus();
        $('#openid_url').select();
        $.cookie('preferred_auth', 'openid');
    },

    showDatabase: function(container) {
        $('#openid_auth_form').hide();
        $('#database_auth_form').show();
        $('#alternate_auth_database').hide();
        $('#alternate_auth_openid').show();
        $('#alternate_auth_cas').show();
        $('#user_login').focus();
        $('#user_login').select();
        $.cookie('preferred_auth', 'database');
    },
    showCAS: function(container) {
        $('#database_auth_form').hide();
        $('#openid_auth_form').hide();
        $('#cas_auth_form').show();
        $('#alternate_auth_cas').hide();
        $('#alternate_auth_openid').show();
        $('#alternate_auth_database').show();
        $.cookie('preferred_auth', 'cas');
    }

}

</script>