Saturday, July 13, 2019

Swift - Notify ViewController from AppDelegate On FCM / APN


Recently I tried  my hands on iOS app after long time as I had to convert one of our hybrid app to native app on urgent basis. There I had webview where I was loading my html app. On FCM message receieved we need to send URL received in FCM to webview and load the URL.

So here in this blog I will mention the procedure for it.

First of all in AppDelegate we have didReceiveRemoteNotification method. There we will create notification for it. Here is the code.

let url = dict
serverURL = url;
let notificationName = Notification.Name("updateWebView") notificationName, object: nil)

Now in the ViewController where you want to make updates, subscribe to this notification in viewDidLoad function.

override func viewDidLoad() {
  let notificationName = Notification.Name("updateWebView")
  NotificationCenter.default.addObserver(self, selector:            #selector(ViewController.updateWebView), name: notificationName, object: nil)

And then add function in ViewController.

@objc func updateWebView() {
  let appDelegate = UIApplication.shared.delegate as! AppDelegate
  let serverURL = appDelegate.serverURL
  guard let url = URL(string: serverURL!) else {
     print("Invalid URL")
  let request = URLRequest(url: url)

That's it and now you will have data passed from AppDelegate to ViewController. This method you can pass any kind of data from FCM to respective ViewController.

Hope this helps you.