Rails3, oauth2 and canvas facebook application - stay in the fb canvas please - facebook

Question

I'm trying to make a canvas facebook app using rails 3 and oauth2.
It kind of works fine following the steps here https://github.com/intridea/oauth2
So when I go to the app in FB, it triggers the methods set by oauth2 BUT, it asks the user to give the permissions OUTSIDE of the canvas, it goes out of FB. Then when the user gives permission it goes where it is supposed to go in the application but again everything OUTSIDE FB.
After giving the permissions if I go to the app inside FB then it shows the app within the canvas.
Anyone familiar with this?
Cheers.

Answer 1

As I know, the page, where you give permissions to app should be outside of app page.
And if you want for than be redirected to your FB app page, you should use
access_token = client.web_server.get_access_token(params[:code], :redirect_uri => redirect_uri)
def redirect_uri
uri = URI.parse(request.url)
uri.path = '/fbcanvas'
uri.query = nil
uri.to_s
end
redirect_uri method is specially used here, so when you are redirected from your fb app page, you'll return there, and if you are redirected from your site itself, you'll return to your site.

Answer 2

I actually changed gems.
What I'm using now is devise_oauth2_canvas_facebook gem.
https://github.com/ninajansen/devise_oauth2_canvas_facebook
It works together with devise and fbgraph and it worked pretty much out of the box, so I recommend that for canvas fb apps.
And everything stays inside the fb canvas :-)
Regards.

Answer 3

I had the same problem and answered my own question. You need to add the code below to application_contoller as per the OmniAuth Overview wiki page. But take care to use request.env["HTTP_REFERER"] rather than request.full_path.
def authenticate_user!
if !current_user
# This should work, but session is lost. See https://github.com/plataformatec/devise/issues/1357
# session[:return_to] = request.fullpath
redirect_to user_omniauth_authorize_path(:google_apps, :origin => request.env["HTTP_REFERER"])
end
end
def after_sign_in_path_for(resource)
# This should work, but session is lost. See https://github.com/plataformatec/devise/issues/1357
# return_to = session[:return_to]
# session[:return_to] = nil
return_to = request.env['omniauth.origin']
stored_location_for(resource) || return_to || root_path
end