We, Backup Box, are a one page app and we do OAuth without redirect all the time. In fact we have one script that handles all the OAuth processes and any new ones we need to create just pop in and there's no customization to be done.
I open a new window (tab) with the OAuth process and since I opened the tab I can redirect to some quick closing script and my main code is waiting for the auth process to finish. Once it does the user is through. Easy peasy.
I open a new window (tab) with the OAuth process and since I opened the tab I can redirect to some quick closing script and my main code is waiting for the auth process to finish. Once it does the user is through. Easy peasy.
https://mybackupbox.com