Apex Code Development 
I'm trying to contact the salesforce api from my rails app. I use omniauth-salesforce gem for oauth.
As mentioned in the REST API documentation, I have setup a remote access provider in "Setup". This asks me for a static callback URL. But the issue with my system, each user of my app gets a different domain. So, I cannot set a constant callback url like "user1.demoapp.com". I will have basically 100 domains for 100 users. So, is it possible to override this callback URL from my rails app? Please let me know.
Interesting problem. We're bound by what the OAuth 2.0 specification says and the endpoint is supposed to be firm. You could have a static endpoint with an HTTP proxy on your end that routes the request to the right place. See the Apache2 httpd and mod_proxy.
Hi
I´m facing a similar problem. Have you implemented a solution? Could be, creating a new Remote Access for each customer with a different callback url, a workaround?
Regards
regards,