Data Doesn't Load Unless UIButton Clicked - objective-c

Question

This might be a strange case so I apologize in advance if my problem or solution is unclear:
I have a LoginViewController that fetches a users Facebook profile picture, username, email, etc. I then have it segue to a HomeViewController that displays some objects, other items, and a UIView that shows the users profile picture.
The strange part is that the UIImage that i create only gets transferred when I use a UIButton. I can not seem to get the image to be sent to the HomeViewController any other way. I even set up a GCP to have it try and wait in order for Facebook to deliver the information - still nothing. Below is the code that I have for the LoginViewController.m. If anyone has any idea on why this is happening I would be extremely grateful. thank you!
#import "LoginViewController.h"
#import <QuartzCore/QuartzCore.h>
#interface LoginViewController ()
- (void)toggleHiddenState:(BOOL)shouldHide;
#end
#implementation LoginViewController
#synthesize profPicture;
- (void)viewDidLoad {
[super viewDidLoad];
[self toggleHiddenState:YES];
self.lblLoginStatus.text = #"";
self.loginButton.readPermissions = #[#"public_profile", #"email"];
self.loginButton.delegate = self;
// Do any additional setup after loading the view.
}
-(void)toggleHiddenState:(BOOL)shouldHide{
self.lblUsername.hidden = shouldHide;
self.lblEmail.hidden = shouldHide;
self.profilePicture.hidden = shouldHide;
self.loggedinwallpaper.hidden = shouldHide;
self.FBlogout.hidden = shouldHide;
}
-(void)loginViewShowingLoggedInUser:(FBLoginView *)loginView{
self.lblLoginStatus.text = #"";
[self toggleHiddenState:NO];
}
-(void)loginViewShowingLoggedOutUser:(FBLoginView *)loginView{
self.lblLoginStatus.text = #"";
[self toggleHiddenState:YES];
}
-(void)loginViewFetchedUserInfo:(FBLoginView *)loginView user:(id<FBGraphUser>)user{
NSLog(#"%#", user);
self.profilePicture.profileID = user.objectID;
self.lblUsername.text = user.name;
self.lblEmail.text = [user objectForKey:#"email"];
dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^(void){
// Create Facebook Profile Picture from User ID url
NSString *pic_link = [NSString stringWithFormat:#"http://graph.facebook.com/%#/picture?width=300&height=300", user.objectID];
NSURL *pic_url = [NSURL URLWithString:pic_link];
profPicture = [UIImage imageWithData: [NSData dataWithContentsOfURL:pic_url]];
dispatch_async(dispatch_get_main_queue(), ^(void){
//Main Thread : UI Updates
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
UIViewController *homeViewController = (UIViewController *)[storyboard instantiateViewControllerWithIdentifier:#"HomeViewController"];
[self performSelector:#selector(prepareForSegue:sender:) withObject:nil afterDelay:1.0 ];
[self presentViewController:homeViewController animated:YES completion:nil];
});
});
}
-(void)loginView:(FBLoginView *)loginView handleError:(NSError *)error{
NSLog(#"%#", [error localizedDescription]);
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
HomeViewController *homeviewController = segue.destinationViewController;
homeviewController.homepic = profPicture;
}
#end

Answer 1

From the code you shared I'd assume that the button you mentioned worked because you wired that up in the Storyboard with a segue, right? (Dragged an arrow to the next VC?)
The issue with your code is that here
[self performSelector:#selector(prepareForSegue:sender:) withObject:nil afterDelay:1.0 ];
you are triggering prepareForSegue:sender: on your own without the necessary parameters - you don't have a segue to prepare for as you aren't even segueing to the other view controller. So when HomeViewController *homeviewController = segue.destinationViewController; is executed segue is nil so the image can't be set.
You should be able to fix this by replacing your code which runs on the main thread with this:
dispatch_async(dispatch_get_main_queue(), ^(void){
// Main Thread : UI Updates
[self performSegueWithIdentifier:#"<insert segue identifier here>" sender:self];
});
Make sure to set a name in your Storyboard for the segue between the view controllers and use that identifier here. (See the Apple Docs)

Answer 2

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
HomeViewController *homeviewController = segue.destinationViewController;
homeviewController.homepic = [UIImage alloc] init];
homeviewController.homepic = profPicture;
}