ios how to send refreshToken from appdelegate to viewcontroller - ios

Question

I am a beginner in developing IOS app. Now i want to send a refreshToken data from a method in AppDelegate to mainViewController.
i can't get it first time when download it. But second time i can get it.
i think it takes some time when it creation first time and it is stored after.
Please help me, how to send data in a method from AppDelegate to ViewController. ultimately, i want to store it to database and send push notification message to user from serverside.
i use following code.
//AppDelegate.h
#class ViewController;
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface AppDelegate : UIResponder <UIApplicationDelegate>
#property (weak, nonatomic) ViewController *myViewController;
#property (strong, nonatomic) UIWindow *window;
#property (weak, nonatomic) IBOutlet UIWebView *webView;
#end
//AppDelegate.m
- (void)tokenRefreshCallback: (NSNotification *)notification {
NSString *refreshToken = [[FIRInstanceID instanceID] token];
NSLog(#"InstanceID token: %#", refreshToken);
//
if(refreshToken){
[[NSUserDefaults standardUserDefaults] setObject:refreshToken forKey:#"token"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
// Connect to FCM since connection may have failed when attempted before having a token.
[self connectToFirebase];
}
//ViewController.h
#import <UIKit/UIKit.h>
#import "AppDelegate.h"
#interface ViewController : UIViewController
#end
//ViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
appDelegate.myViewController = self;
//get tokenId
NSString *token = [[NSUserDefaults standardUserDefaults] objectForKey:#"token"];
if(token){
NSLog(#"i have token~!!!: %# ", token);
}else NSLog(#"no token!: %# ", token);
// Do any additional setup after loading the view, typically from a nib.
}
Thanks all.

Answer 1

use NSNotifiactionCenter
in your Appdelegate when token is available post a notification with the token(add following code in app delegate where token is available)
NSDictionary* userInfo = #{#"token": #"YOUR_TOKEN"};
[[NSNotificationCenter defaultCenter] postNotificationName:#"refreshTokenAvailale" object:self userInfo:userInfo];
And put this code in your main view controller
- (void) dealloc
{
// If you don't remove yourself as an observer, the Notification Center
// will continue to try and send notification objects to the deallocated
// object.
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
- (id) init
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(receiveNotification:)
name:#"refreshTokenAvailale"
object:nil];
return self;
}
- (void) receiveNotification:(NSNotification *) notification
{
if ([notification.name isEqualToString:#"refreshTokenAvailale"])
{
NSDictionary* userInfo = notification.userInfo;
NSString* token = userInfo[#"token"];
}
}