Devise and stored_location_for: how do you store the return location? - ruby-on-rails-3

Question

I have a page whose path is (e.g.) /premises/92 on which I'm displaying "please [log in] or [register] for additional information" if the user is not logged in, and I want devise to return that same /premises/92 page after the user logs in.
I've read other posts and I think I understand how devise's stored_location_for is supposed to work. In theory, I could put something like this in my ApplicationController:
def stored_location_for(resource)
if (r = session[:return_to])
session[:return_to] = nil
r
else
super
end
end
My question is: how / where do I set up session[:return_to]?
I want to set session[:return_to] only if the user clicks on [log in] or [register], but what's the best way to do that?
Decorate the links with JavaScript? That could work, but seems heavy-handed.
Set it in the Premises Controller before rendering the page? That doesn't seem right: what if the user doesn't click on the [log in] or [register] links? Then I have session[:return_to] set to some odd value which might trip me up if the user logs in from some other page.
Add a ?return_to=/premises/92 query string to the [log in] and [register] links, and detect that in the RegistrationsController and SessionsController and use that info to set up session[:return_to]? That seems like it would work, but also heavy-handed.
None of these smell right. What's the generally accepted technique for setting up state for stored_location_for?

Answer 1

Devise use
session["#{scope}_return_to"]
So you can use session["user_return_to"] if your model for authentication is User.

Answer 2

I found this whole devise redirect thing quite confusing.
Where #rorra says Devise uses session["#{scope}_return_to"], he means that Devise default after_sign_in_path_for(resource) will use that variable through the method stored_location_for(resource).
So you should save the location you want to store in the variable session["#{scope}_return_to"], which will usually be session["user_return_to"]. To do this place the following in your application_controller.rb:
after_action :store_location
def store_location
# store last url - this is needed for post-login redirect to whatever the user last visited.
if (request.fullpath != "/users/sign_in" &&
request.fullpath != "/users/sign_up" &&
request.fullpath != "/users/password" &&
request.fullpath != "/users/sign_out" &&
!request.xhr?) # don't store ajax calls
session["user_return_to"] = request.fullpath
end
end
In some cases you will not need to define an after_sign_in_path_for(resource) method as devise's default method will do all the redirects for you and if their is no redirect url available you will be redirected to the resource root path (usually user root path) and if that doesn't exist you will be redirected to the root path. If however, you would like to customise where the user is sent if there is no redirect url available, add the following to your application_contorller.rb (and change root_path accordingly):
def after_sign_in_path_for(resource)
stored_location_for(resource) || root_path
end

Answer 3

Devise looks for the key "#{resource}_return_to" in the session.
Here I am quoting the API:
By default, it first tries to find a valid #{resource}_return_to key in
the session, then it fallbacks to #{resource}_root_path, otherwise it
uses the root_path.
Here is the link to the API

Answer 4

here's the best I could come up with. Works perfectly also with facebook authentication. by adding more restrictions to the prepending of urls to the session variable you can remove more and more paths you don't want the user to return too (e.g. callbacks, splash pages, landing pages, etc)
#ApplicationsController
after_filter :store_location
def store_location
session[:previous_urls] ||= []
# store unique urls only
session[:previous_urls].prepend request.fullpath if session[:previous_urls].first != request.fullpath && request.fullpath != "/user" && request.fullpath != "/user/login" && request.fullpath != "/" && request.fullpath != "/user/logout" && request.fullpath != "/user/join" && request.fullpath != "/user/auth/facebook/callback"
# For Rails < 3.2
# session[:previous_urls].unshift request.fullpath if session[:previous_urls].first != request.fullpath
session[:previous_urls].pop if session[:previous_urls].count > 3
end
def after_sign_in_path_for(resource)
#url = session[:previous_urls].reverse.first
if #url != nil
"http://www.google.com" + #url
else
root_path
end
end

Answer 5

I do like this:
class ApplicationController < AC::Base
after_filter :clear_attached_unit # UPDATED
protected
def clear_attached_unit
session[:attached_unit_path] = nil unless keep_attached_unit_path?
end
def keep_attached_unit_path? # UPDATED
#keep_attached_unit_path
end
end
class UnitController < ApplicationController
before_filter :attach_unit, :only => [:show]
protected
def attach_unit
session[:attached_unit_path] = request.url if request.get? && !request.xhr?
end
end
class SessionsController < Devise::SessionsController
before_filter :keep_attached_unit_path! # UPDATED
protected
def keep_attached_unit_path! # UPDATED
#keep_attached_unit_path = true
end
def after_sign_in_path_for(resource_or_scope)
if resource_or_scope.is_a?(User) && session[:attached_unit_path].present?
session[:attached_unit_path]
else
super
end
end
end
And extract this to module.