Custom button Sign in Facebook swift 4

Facebook Login in Swift 4

     The Facebook SDK in Swift enables people to sign into your app with Facebook Login. When people log into your app with Facebook they can grant permissions to your app so that you can retrieve information or perform actions on the Facebook platform on their behalf.

First you must install CocoaPods facebook. To use the SDK with CocoaPods, add the following lines to your Podfile:

https://developers.facebook.com/docs/swift/getting-started

pod 'FacebookCore'
pod 'FacebookLogin'
pod 'FacebookShare' // if needed


Click this link to ragister your app for login https://developers.facebook.com/docs/facebook-login/ios. This is how costum button using .xib





-- info.plist --> rightClick --> open As --> Source Code

Copy & Paste an XML snippet into your file contents (<dict> ... </ dict>).

<key>CFBundleURLTypes</key>
<array>
  <dict>
  <key>CFBundleURLSchemes</key>
  <array>
    <string>fb(YourAppID)</string>
  </array>
  </dict>
</array>
<key>FacebookAppID</key>
<string>(YourID)</string>
<key>FacebookDisplayName</key>
<string>(YourApp)</string>

- newfile --> cocoa touch class --> viewController

- now use button, like this image

- add button to .xib file and use this code in your  viewController.swift

import UIKit

import FacebookLogin

import FBSDKLoginKit



class FacebookLoginViewController: UIViewController {

    

    

    @IBAction func bLoginF(_ sender: Any) {

        

        let loginManager = LoginManager()

        loginManager.logIn(readPermissions: [.publicProfile], viewController : self) { loginResult in

            

            switch loginResult {

            case .failed(let error):

                print(error)

            case .cancelled:

                print("User cancelled login.")

            case .success(let grantedPermissions, let declinedPermissions, let accessToken):

                self.getFBUserData()

            }

        }

        

    }



    var dict : [String : AnyObject]!

    

    override func viewDidLoad() {

        super.viewDidLoad()



        

        //if the user is already logged in

        if (FBSDKAccessToken.current()) != nil{

            getFBUserData()

        }

    }

    

        

        //function is fetching the user data

        func getFBUserData() {

            if((FBSDKAccessToken.current()) != nil){

                FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, picture.type(large), email"]).start(completionHandler: { (connection, result, error) -> Void in

                    if (error == nil){

                        self.dict = result as! [String : AnyObject]

                        print(result!)

                        print(self.dict)

                    }

                })

            }

        }

}

-- in your appdelegate.swift 

1 . add func FBSDKapplicationDelegate -- > didFinishLaunchingWithOptions

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        

        FBSDKApplicationDelegate.sharedInstance().application(application, didFinishLaunchingWithOptions: launchOptions)

        

        window = UIWindow(frame: UIScreen.main.bounds)

        window?.makeKeyAndVisible()

        window?.rootViewController = UINavigationController(rootViewController: FacebookLoginViewController())

        

        return true

    }

2 . add func FBSDKAppEvents

    func applicationWillResignActive(_ application: UIApplication) {


        FBSDKAppEvents.activateApp()

    }

3 . add func FBSDKapplicationDelegate --> sourceApplication

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

  return FBSDKApplicationDelegate.sharedInstance().application(application, open: url, sourceApplication: sourceApplication, annotation: annotation)

    }

      

full class AppDelegate

import UIKit

import FBSDKLoginKit

@UIApplicationMain

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        

        FBSDKApplicationDelegate.sharedInstance().application(application, didFinishLaunchingWithOptions: launchOptions)

        

        window = UIWindow(frame: UIScreen.main.bounds)

        window?.makeKeyAndVisible()

        window?.rootViewController = UINavigationController(rootViewController: FacebookLoginViewController())

        

        return true

    }

    func applicationWillResignActive(_ application: UIApplication) {

        FBSDKAppEvents.activateApp()

    }

    

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

        return FBSDKApplicationDelegate.sharedInstance().application(application, open: url, sourceApplication: sourceApplication, annotation: annotation)

    }

    func applicationDidEnterBackground(_ application: UIApplication) {

        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.

        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.

    }

    func applicationWillEnterForeground(_ application: UIApplication) {

        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.

    }

    func applicationDidBecomeActive(_ application: UIApplication) {

        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.

    }

    func applicationWillTerminate(_ application: UIApplication) {

        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.

    }

}

This my note as my problem and solution @luffyselah