Update the UI of the View Controller and then dismiss it - ios

Question

I have a view controller, that loads some an array. While everything is loading, I need to present another view controller (with the UIProgressView) and update it's UI (the progress property of a UIProgressView) and then dismiss and present first vc with downloaded data. I'm really struggling on it and I've tried delegation, but nothing worked for me.
- (void)viewDidLoad
{
[super viewDidLoad];
if ([[NSUserDefaults standardUserDefaults] boolForKey:#"downloaded"]) {
} else {
NSLog(#"First time Launched");
ProgressIndicatorViewController *progressVC = [ProgressIndicatorViewController new];
progressVC.modalPresentationStyle = UIModalPresentationFullScreen;
[self syncContacts];
[self presentViewController:progressVC animated:YES completion:nil];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:#"downloaded"];
[progressVC release];
}
}
sync contacts method:
- (void)syncContacts
{
NSLog(#"Sync data");
NSMutableArray *allContacts = [ContactsOperations getAllContactsFromAddressBook];
NSInteger allContactsCount = [allContacts count];
if (allContactsCount > 0) {
for (ContactData *contact in allContacts) {
NSMutableArray *phoneNumbersArray = [[NSMutableArray alloc] init];
NSString *nospacestring = nil;
for (UserTelephone *tel in [contact.abonNumbers retain]) {
NSArray *words = [tel.phoneNumber componentsSeparatedByCharactersInSet :[NSCharacterSet whitespaceCharacterSet]];
NSString *nospacestring = [words componentsJoinedByString:#""];
[phoneNumbersArray addObject:nospacestring];
}
contact.abonNumbers = phoneNumbersArray;
if (phoneNumbersArray != nil) {
NSLog(#"NOT NULL PHONENUMBERS: %#", phoneNumbersArray);
}
NSDictionary *dataDictionary = [[NSDictionary alloc] initWithObjectsAndKeys:contact.abonNumbers, #"phoneNumbers", contact.contactName, #"fullName", [NSNumber numberWithBool:contact.isBlackList], #"blacklist", [NSNumber numberWithBool:contact.isIgnore], #"ignore", contact.status, #"status", nil];
NSLog(#"dictionary: %#", dataDictionary);
NSError *error;
NSData *postData = [NSJSONSerialization dataWithJSONObject:dataDictionary options:0 error:&error];
NSLog(#"POST DATA IS : %#", postData);
NSMutableURLRequest *newRequest = [self generateRequest:[[NSString stringWithFormat:#"%#c/contacts%#%#", AVATATOR_ADDR, SESSION_PART, [[ServiceWorker sharedInstance] SessionID]] stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding] withHTTPMethod:#"POST"];
[newRequest setHTTPBody:postData];
[newRequest setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
//__block NSMutableData *newData;
[NSURLConnection sendAsynchronousRequest:newRequest queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError)
{
if (!connectionError) {
NSDictionary *allData = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(#"alldata from contacts: %#", allData);
//NSInteger errorCode = [[allData objectForKey:#"CommandRes"] integerValue];
//if (errorCode == 0) {
NSInteger remoteId = [[allData objectForKey:#"contactId"] integerValue];
contact.remoteId = remoteId;
NSLog(#"remote id is from parse content : %d", remoteId);
[[AvatatorDBManager getSharedDBManager]createContactWithContactData:contact];
} else {
NSLog(#"error");
}
}];
//Somewhere here I need to update the UI in another VC
[phoneNumbersArray release];
[dataDictionary release];
}
} else {
}
}
generate request method:
- (NSMutableURLRequest *)generateRequest:(NSString *)urlString withHTTPMethod:(NSString *)httpMethod
{
NSLog(#"url is :%#", urlString);
NSURL *url = [NSURL URLWithString:urlString];
request = [NSMutableURLRequest requestWithURL:url];
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[request setHTTPMethod:httpMethod];
return request;
}
ProgressViewController is just an empty VC with the progress bar. No code yet.

Answer 1

In the view controller that will display the progress view expose a method like this...
- (void)updateProgress:(float)progress;
Its implementation will look like this...
- (void)updateProgress:(float)progress {
[self.progressView setProgress:progress animated:YES];
}
On the main view controller you need to execute the long-running process on a background thread. Here's viewDidLoad for the main view controller. This example code uses a property for the progress view controller (you may not require this) and assumes your are in a navigation controller...
- (void)viewDidLoad {
[super viewDidLoad];
// Create and push the progress view controller...
self.pvc = [[ProgressViewController alloc] init];
[self.navigationController pushViewController:self.pvc animated:YES];
// Your long-running process executes on a background thread...
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Your long-running process goes here. Wherever required you would
// call updateProgress but that needs to happen on the main queue...
dispatch_async(dispatch_get_main_queue(), ^{
[self.pvc updateProgress:progress];
});
// At the end pop the progress view controller...
dispatch_async(dispatch_get_main_queue(), ^{
[self.navigationController popViewControllerAnimated:YES];
});
});
}