PFFile image not loaded before attaching to PFImageView? - ios

Question

I'm using Parse with Facebook login to create a new user. I get a few fields from Facebook like their name and location, request their profile image to load in the background before I segue to my main view controller which has a PFImageView for the profile image.
The problem is that the PFFile user[#"profileImage"] is still nil by the time the main view controller's viewDidLoad fires, so there's nothing to loadInBackground.
I don't want to wait for the profile image to load before going to the main view controller...that would take some random time and just be bad.
So, how to I deal with a PFFile that hasn't loaded before I give it to the PFFImageView? Some kind of placeholder?
Here's my code:
------- in LoginViewController.m
- (void) pressedFacebookLogin {
[PFFacebookUtils logInWithPermissions...
if(user.isNew) {
FBRequest *request = [FBRequest requestForMe];
[request startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
NSDictionary *userData = (NSDictionary *)result;
user[#"fullName"] = userData[#"name"];
// get location, relationship if available
[user saveInBackground];
// start getting the user's profile image before going to main view controller
NSURL *pictureURL = [NSURL URLWithString:[NSString stringWithFormat:#"https://graph.facebook.com/%#/picture?type=large&return_ssl_resources=1", facebookID]];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:pictureURL];
[NSURLConnection sendAsynchronousRequest:urlRequest queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
if (connectionError == nil && data != nil) {
UIImage *tmpImage = [UIImage imageWithData:data];
NSData *imageData = UIImagePNGRepresentation(tmpImage);
PFFile *imageFile = [PFFile fileWithName:#"image.png" data:imageData];
user[#"profileImage"] = imageFile;
[user saveInBackground];
}
}];
[self segueToMainViewController];
}];
}else {
// deal with existing user...
}
}];
}
-------------- in MainViewController.m
- (void) viewDidLoad {
[super viewDidLoad];
PFUser *user = [PFUser currentUser];
self.profileImageView.image = [UIImage imageNamed:#"placeholder"];
PFFile *profileImageFile = user[#"profileImage"];
// at this point profileImageFile is nil
self.profileImageView.file = profileImageFile;
[self.profileImageView loadInBackground];
}

Answer 1

In the place where you get the profileImageFile as empty add this line.
I guess the profileImageView you use is a ImageView.
#property (weak, nonatomic) IBOutlet UIImageView *profileImageView;
// at this line where you get profileImageFile as nil
[self.profileImageView setImageWithURL:[NSURL URLWithString:user[#"profileImage"]] placeholderImage:[UIImage imageNamed:#"default_profileImage"]];