My solution to highlight correct menu item (using simple_navigation gem), when :create action fails

gistfile1.rb

# In config/simple_navigation.rb
require 'simple_navigation/rails_controller_methods'

ActionController::Base.class_eval do
  def self.disable_navigation_auto_highlighting(*args)
    around_filter :temporary_disable_simple_navigation_auto_highlighting, *args
  end

  def temporary_disable_simple_navigation_auto_highlighting
    auto_highlight = SimpleNavigation::Configuration.instance.auto_highlight
    SimpleNavigation::Configuration.instance.auto_highlight = false
    yield
    SimpleNavigation::Configuration.instance.auto_highlight = auto_highlight
  end
  private :temporary_disable_simple_navigation_auto_highlighting
end

# In my controller
class Admin::SystemAlertsController < Admin::BaseController
  # ...
  disable_navigation_auto_highlighting :only => :create

  def create
    current_navigation :new_system_alert
    if system_alert.save
      flash[:notice] = "System alert saved!"
      redirect_to :action => :index
    else
      render :action => :new
    end
  end
end