Beginner programmer here, please pardon ignorance & explanations will be really nice :)
I\'ve tried to read the tutorials for a certain OAuth 2.0 service, but I
Take a look at OAuth 2.0 playground.You will get an overview of the protocol.It is basically an environment(like any app) that shows you the steps involved in the protocol.
https://developers.google.com/oauthplayground/
If you are using Facebook SDK, you don't need to bother yourself to enter anything for redirect URI on the app management page of facebook. Just setup a URL scheme for your iOS app. The URL scheme of your app should be a value "fbxxxxxxxxxxx" where xxxxxxxxxxx is your app id as identified on facebook. To setup URL scheme for your iOS app, go to info tab of your app settings and add URL Type.
redirected uri is the location where the user will be redirected after successfully login to your app. for example to get access token for your app in facebook you need to subimt redirected uri which is nothing only the app Domain that your provide when you create your facebook app.
Read this:
http://www.quora.com/OAuth-2-0/How-does-OAuth-2-0-work
or an even simpler but quick explanation:
http://agileanswer.blogspot.se/2012/08/oauth-20-for-my-ninth-grader.html
The redirect URI is the callback entry point of the app. Think about how OAuth for Facebook works - after end user accepts permissions, "something" has to be called by Facebook to get back to the app, and that "something" is the redirect URI. Furthermore, the redirect URI should be different than the initial entry point of the app.
The other key point to this puzzle is that you could launch your app from a URL given to a webview. To do this, i simply followed the guide on here:
http://iosdevelopertips.com/cocoa/launching-your-own-application-via-a-custom-url-scheme.html
and
http://inchoo.net/mobile-development/iphone-development/launching-application-via-url-scheme/
note: on those last 2 links, "http://" works in opening mobile safari but "tel://" doesn't work in simulator
in the first app, I call
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"secondApp://"]];
In my second app, I register "secondApp" (and NOT "secondApp://") as the name of URL Scheme, with my company as the URL identifier.