Add documentation for redirecting to the CAS login pages

[joevandyk]

I'm not sure how to redirect the user to the CAS login/logoff pages. I know I can make the URL by hand, but I thought there'd be a better way? Is there a method for returning the CAS server's login and logoff URLs?

[dlindahl]

When the strategy fails, OmniAuth should handle the redirect itself. It will 302 the user to the URL defined in the login_url configuration option

Is that what you were looking for?

[joevandyk]

I might sometimes need to redirect people there outside of omniauth.

[dlindahl]

Unfortunately, I don't think that the OmniAuth API exposes a strategy's configuration options. I would suggest storing the login_url in a different location and use that variable when configuring OmniAuth::CAS.

In Rails, you should be able to do something like this:

# config/routes.rb
match 'users/sign_in' => 'users#sign_in', as: :sign_in

# config/initializers/omniauth.rb
Rails.application.config.middleware.use OmniAuth::Builder do
  provider :cas, host: 'cas.yourdomain.com', login_url: sign_in_path
end

Which would allow you to do this elsewhere:

<% link_to 'Sign In', sign_in_path %>