Gateway login pages are ones where a user doesn't need to be logged-in... but if they already *are* logged in, then we want to know. Example: the help or contact-us pages are available to non-logged-in users.
Often we want to write these pages using the existing templates so that if they aren't logged in, the templates are fairly simple, but if they *are* logged in, then you display the usual logged-in navigation links.
So you need a filter that will auto-authenticate a user *if* they are already logged in, but doesn't *require* it. The standard CAS-login filters will actually redirect non-logged in users to the login page - and we don't want that happening. So we need to write a little filter-magick using the CAS GatewayFilter.
class WelcomeController < ApplicationController
# don't *require* login for the public pages (inc actual login page)
skip_before_filter CASClient::Frameworks::Rails::Filter, :only => [:home, :contact_us, :terms, :cas_login]
# instead use gateway-login filter
before_filter :cas_gateway_login, :only => [:home, :contact_us, :terms, :cas_login]
# ... lots of actions and stuff here
#####################################################################################
private
# This before_filter method is used to both call the GatewayFilter and
# also to then call the setup_cas_user method. Note that the latter
# will already have been called on an action, but as we declare the
# GatewayFilter *after* this, it must be declared again. So we use this
# method to make sure that we do both of these in the requisite
# before_filter.
def cas_gateway_login
return false unless CASClient::Frameworks::Rails::GatewayFilter
setup_cas_user # setup @cas_current_user etc for use by other methods
end
end # controller
After this, you can use the logged_in? method to determine whether or not to display extra navigation features.
This is one article in a series on Rails single-sign-on with rubyCAS
