grails: reusable authentication interceptor

Question

I found an example of simple grails auth where a beforeInterceptor is used in a controller to redirect users out if they are not logged in. it looks like this:

  def beforeInterceptor = [action:this.&checkUser,except:['login']]
  def checkUser() {
    if(!session.user) {
      redirect(controller:'home')
      return false
    }
  }

This is all well and good if you only have one controller that you must secure. what happens when you have more then one? I cant put the checkUser method into a service because a service cannot redirect, and probably doesnt have the session object. Please help

Answer 1

you would want to use a grails filters, http://grails.org/doc/latest/ref/Plug-ins/filters.html

but I would strongly suggest you look into Grails Spring Security instead

Answer 2

Grails Filters ought to do the trick. The linked page has an example of using a filter for authentication.