CODEWITHSUNDEEP
iosswift
Eric Walters
Eric Walters

Reputation: 311

Issue Passing Data To Different View Controller With Segue

I am attempting to pass an object from one view controller to another and the object seems to be empty when the next view controller is called. I found other forums that recommended I use something similar to this to pass a my User object.

var user: User!
override func viewDidLoad() {
        super.viewDidLoad()

        oauthswift = OAuth1Swift(
            consumerKey:    CONSUMER_KEY,
            consumerSecret: CONSUMER_SECRET,
            requestTokenUrl: "https://api.twitter.com/oauth/request_token",
            authorizeUrl:    "https://api.twitter.com/oauth/authorize",
            accessTokenUrl:  "https://api.twitter.com/oauth/access_token"
        )
        handle = oauthswift.authorize(
            withCallbackURL: URL(string: "oauth-swift://oauth-callback/twitter")!,
            success: { credential, response, parameters in
                print("OAuthToken: \(credential.oauthToken)")
                print("OAuthSecret: \(credential.oauthTokenSecret)")
                print("User ID: \(parameters["user_id"]!)")
                self.user = User(oauthswift: self.oauthswift, consumerKey: CONSUMER_KEY, consumerSecret: CONSUMER_SECRET, oAuthToken: credential.oauthToken, oAuthSecret: credential.oauthTokenSecret)
                func prepare(for segue: UIStoryboardSegue, sender: Any?) {
                    if let feedViewController = segue.destination as? FeedViewController {
                        feedViewController.user = self.user
                    }
                }
                self.performSegue(withIdentifier: "goToFeed", sender: self)
                // Do your request
        },
            failure: { error in
                print(error.localizedDescription)
                print(self.handle)
        }
        )

        // Do any additional setup after loading the view, typically from a nib.
    }

When goToFeed is executed, the User object is empty. I am performing the initialization within the closure so it would seem to me that the User should be fully populated. I assume the way I am using the segue function is incorrect? Any thoughts are appreciated.

Upvotes: 0

Views: 39

Answers (1)

Duncan C
Duncan C

Reputation: 131398

You misunderstand how to use prepare(for:). It must be a top-level instance method, not a nested function. It will get called after you call performSegue(withIdentifier:):

var user: User!

func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let feedViewController = segue.destination as? FeedViewController {
      feedViewController.user = self.user
    }
}

override func viewDidLoad() {
        super.viewDidLoad()

        oauthswift = OAuth1Swift(
            consumerKey:    CONSUMER_KEY,
            consumerSecret: CONSUMER_SECRET,
            requestTokenUrl: "https://api.twitter.com/oauth/request_token",
            authorizeUrl:    "https://api.twitter.com/oauth/authorize",
            accessTokenUrl:  "https://api.twitter.com/oauth/access_token"
        )
        handle = oauthswift.authorize(
            withCallbackURL: URL(string: "oauth-swift://oauth-callback/twitter")!,
            success: { credential, response, parameters in
                print("OAuthToken: \(credential.oauthToken)")
                print("OAuthSecret: \(credential.oauthTokenSecret)")
                print("User ID: \(parameters["user_id"]!)")
                self.user = User(oauthswift: self.oauthswift, consumerKey: CONSUMER_KEY, consumerSecret: CONSUMER_SECRET, oAuthToken: credential.oauthToken, oAuthSecret: credential.oauthTokenSecret)
                self.performSegue(withIdentifier: "goToFeed", sender: self)
                // Do your request
        },
            failure: { error in
                print(error.localizedDescription)
                print(self.handle)
        }
        )

        // Do any additional setup after loading the view, typically from a nib.
    }

Upvotes: 2

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