application.html.erb

<% if user_signed_in? %>
      <p class="grid_12 derecha">
        <span class="persona" id="ficha" data-ficha="<%= current_user.id %>"><%= current_user.nombres %></small></span>  |  <span class="logout"><%= link_to('Salir', destroy_user_session_path) %></span>
      <% else %>

applicationcontroler.rb

  def after_sign_in_path_for(resource_or_scope)
    empleado = Empleado.find(current_user.id)
    current_user.nombres = (empleado.nombres + ' ' + empleado.apellidos).titleize
    Rails.logger.debug("My object: #{current_user.nombres}")
    #RAILS_DEFAULT_LOGGER.debug current_user.nombres

    case resource_or_scope
    when :user, User
      store_location = session[:return_to]
      clear_stored_location
      (store_location.nil?) ? "/overview" : store_location.to_s
    else
      super
    end
  end

En callback

My object: --- !ruby/object:User 
attributes: 
  created_at: 2011-08-24 19:57:55.027023
  estado_id: "1"
  last_sign_in_ip: 127.0.0.1
  updated_at: 2012-08-15 11:57:25.684891 -04:30
  last_sign_in_at: 2012-08-15T09:44:13+00:00
  id: 30018076
  sign_in_count: 59
  remember_token: 
  current_sign_in_ip: 127.0.0.1
  ldap_attributes: 
  remember_created_at: 
  current_sign_in_at: 2012-08-15 11:57:25.633339 -04:30
  login: antonio.bastardo
attributes_cache: {}

changed_attributes: {}

ficha: 30018076
new_record_before_save: false
nombres: Antonio Jose Bastardo Salas

En view

--- !ruby/object:User attributes: created_at: 2011-08-24 19:57:55.027023 estado_id: "1" last_sign_in_ip: 127.0.0.1 updated_at: 2012-08-15 11:57:25.684891 last_sign_in_at: 2012-08-15 09:44:13 id: "30018076" sign_in_count: "59" remember_token: current_sign_in_ip: 127.0.0.1 ldap_attributes: remember_created_at: current_sign_in_at: 2012-08-15 11:57:25.633339 login: antonio.bastardo attributes_cache: {} roles: - !ruby/object:Rol attributes: name: admin rol_id: "3" created_at: updated_at: id: "3" user_id: "30018076" attributes_cache: {}