Facebook login always return 'Cancelled' result in the loginButtonDidCompleteLogin delegate

[lsubramaniyan]

I have integrated latest Swift SDK with my app. When I click on Login button,I can able to navigate to safari browser and after successful login and confirm page, login button delegates called with cancelled status. What could be the issue?

Also, I can able to return back to my app only on iOS versions < 9.0 and on versions iOS 9.0+ I can't able to return back to my application.

[lsubramaniyan]

I tried to the same thing using iOS SDK. Same issues exists.
Posted a question in stack http://stackoverflow.com/questions/39701394/fbsdkloginkit-not-redirect-my-app-after-login-and-confirm-page

[lsubramaniyan]

Guys, I found the issue and its because of APP Transport Security.
I have added below keys in plist to resolve my issue and now its working fine in all iOS versions.
NSAppTransportSecurity

NSExceptionDomains

facebook.com

NSIncludesSubdomains

NSExceptionRequiresForwardSecrecy


fbcdn.net

NSIncludesSubdomains

NSExceptionRequiresForwardSecrecy


akamaihd.net

NSIncludesSubdomains

NSExceptionRequiresForwardSecrecy

[MoridinBG]

The issue is really simple. You have to implement the following method in your App Delegate:

func application(_ application: UIApplication, open url: URL, sourceApplication: String?, annotation: Any) -> Bool

And pass the URL to FBSDKApplicationDelegate. That's it. Login works as expected now

What broke for some people that already implement this is that it is fairly common to only pass the fb authorize URL to the sdk delegate (as you should!) and it is common to do

if url.scheme!.hasPrefix("fb\(FBSDKSettings.appID())")

but FBSDKSettings.appID() is an implicitly unwrapped optional (String!) and Swift 3 changed how they work (https://github.com/apple/swift-evolution/blob/master/proposals/0054-abolish-iuo.md) and the string interpolation expands it to "fbOptional(...". If this is the case, you should change it to

if let fbSDKAppId = FBSDKSettings.appID(), url.scheme!.hasPrefix("fb\(fbSDKAppId)"), url.host == "authorize"

(you could just append another ! to FBSDKSettings.appID() but I hate this)

It's not really Facebook's job what URLs is your app opening, so you should only pass it the authentication URL.