CODEWITHSUNDEEP
iosswift
Hybrid engineer
Hybrid engineer

Reputation: 23

global variable in appdelegate swift4

I have the variable I created in appDelegate. how do I use this variable in ViewController. I've tried a few methods, but. I always got an error. my code is as follows. I am swifte new Please help?

AppDelegate.swift

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {

// refreshedToken is variable. I use it in viewcontroller.
        if let refreshedToken = InstanceID.instanceID().token() {
            print("InstanceID token: \(refreshedToken)")

       }
}

ViewController.swift

   super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let appDelegate = UIApplication.shared.delegate as! AppDelegate


    let purl = URL(string: "")!
    var request = URLRequest(url: purl)
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    request.httpMethod = "GET"
    let postString = "ajax=token&"+"token="+refreshedToken// Use of unresolved identifier 'refreshedToken'

    print("postString: \(postString)")
    request.httpBody = postString.data(using: .utf8)
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    let task = URLSession.shared.dataTask(with: request) { data, response, error in
        guard let data = data, error == nil else {
            print("error=\(String(describing: error))")
            return
        }

        if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 {
            print("statusCode should be 200, but is \(httpStatus.statusCode)")
            print("response = \(String(describing: response))")
        }

        let responseString = String(data: data, encoding: .utf8)
        print("responseString = \(String(describing: responseString))")
    }
    task.resume()






}

how do I use the refreshedToken in ViewController ?

Upvotes: 2

Views: 2688

Answers (4)

Sulaiman Khan
Sulaiman Khan

Reputation: 927

You can handle this with Singleton Model Object which will hold your data and has global access of data from anywhere of your project.

First create a new Model File that will have code written below:

class SingletonDataModel: NSObject {

    var token:String?

    static let sharedInstance = SingletonDataModel()

    private override init() {
        super.init()
    }
}

Secondly save data on this upper model from ApppDelegate class like below:

var refreshedToken : String?

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    // refreshedToken is variable. I use it in viewcontroller.
    if let token = InstanceID.instanceID().token() {
        refreshedToken = token
        SingletonDataModel.sharedInstance.token = token
        print("InstanceID token: \(refreshedToken)")

    }
}

Now your data model singleton is initialized and token value is stored on that object

Finally access that value from your viewDidLoad method of the ViewController Class filelike below: 

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.


    let token = SingletonDataModel.sharedInstance.token

    //Do your work


}

if token is nil , this mean your AppDelegate -> didRegisterForRemoteNotificationsWithDeviceToken method is not called before the initialization of your ViewController. You must ensure that your didRegisterForRemoteNotificationsWithDeviceToken is called before the initialization of your ViewController . Otherwise you have to handle this in different way

Upvotes: 0

Joakim Danielson
Joakim Danielson

Reputation: 52088

You need to understand in what scope you declare a variable and how it is visible outside that scope. Now your variable is only visible inside that func, to make it visible to your view controller it needs to be a class property in AppDelegate.

So define a property like (somewhat simplified code here)

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
   var refreshedToken = InstanceID.instanceID().token()
   ...

}

And then in you can access it in your view controller

let token = appDelegate.refreshedToken

Upvotes: 1

Roshan
Roshan

Reputation: 732

You can save the refresh token in UserDefaults 

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {

// refreshedToken is variable. I use it in viewcontroller.
        if let refreshedToken = InstanceID.instanceID().token() {
            print("InstanceID token: \(refreshedToken)")
            UserDefaults.standard.set(refreshedToken, forKey: "preferenceName")

       }
}

and Later can retrieve the value in ViewController using

let postString = "ajax=token&"+"token="+  UserDefaults.standard.string(forKey: "Key")

Upvotes: 0

Sagar Chauhan
Sagar Chauhan

Reputation: 5823

Just create your refreshedToken globally in appdelegate class and update code as follows:

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var refreshedToken : String?

    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        // refreshedToken is variable. I use it in viewcontroller.
        if let token = InstanceID.instanceID().token() {
            self.refreshedToken = token
            print("InstanceID token: \(refreshedToken)")

        }
    }
}

From above code, refreshedToken available if didRegisterForRemoteNotificationsWithDeviceToken method called otherwise it will be nil.

If you want it global available in application without dependent on any method write following code just after AppDelegate class implementation.

let refreshedToken = InstanceID.instanceID().token()

Upvotes: 0

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