GCD slow updating UI - ios

Question

Im using GCD to download a plist file from the internet then enter the data into an array then load it into a tableView.
The data is being downloaded and converted alright but the table view is taking ages to update. I have the app Logging something when it calls [self.tableView reloadData] but the table view updates about 10 seconds later.
I don't think this is about the table view because I tried changing the title of the Navigation Bar inside the GCD and there was also a delay. So it might be a delay updating the user interface?
This is my GCD code:
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
Thanks for you help
EDIT:
This is my code:
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
UERootArray = [[NSArray alloc] initWithContentsOfURL:[NSURL URLWithString:#"url to file"]];
NSLog(#"Array: %#", UERootArray);
//NSLog(#"count %#",count);
NSString *currentName;
NSString *currentLoaction;
NSString *currentDate;
int currentEventInt = 0;
NSArray *currentEventArr = [UERootArray objectAtIndex:0];
while (currentEventArr.count > currentEventInt)
{
currentName = [currentEventArr objectAtIndex:0];
currentLoaction = [currentEventArr objectAtIndex:1];
currentDate = #"7pm 17/11"; //[currentEventArr objectAtIndex:2];
NSLog (#"Title: %#", currentName);
NSLog (#"News: %#", currentLoaction);
NSLog (#"Date: %#", currentDate);
UEEvent *currentTask = [[UEEvent alloc] initWithName:currentName location:currentLoaction date:currentDate];
[self.upcommingEvents addObject:currentTask];
currentEventInt = currentEventInt + 1;
}
UEDownloaded = YES;
[self.tableView reloadData];
Edit 2:
- (void)downloadUEData
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
UERootArray = [[NSArray alloc] initWithContentsOfURL:[NSURL URLWithString:#"url to file"]];
[self processUEData];
});
}
- (void)processUEData
{
NSLog(#"Array: %#", UERootArray);
//NSLog(#"count %#",count);
NSString *currentName;
NSString *currentLoaction;
NSString *currentDate;
int currentEventInt = 0;
NSArray *currentEventArr = [UERootArray objectAtIndex:0];
while (currentEventArr.count > currentEventInt)
{
currentName = [currentEventArr objectAtIndex:0];
currentLoaction = [currentEventArr objectAtIndex:1];
currentDate = #"7pm 17/11"; //[currentEventArr objectAtIndex:2];
NSLog (#"Title: %#", currentName);
NSLog (#"News: %#", currentLoaction);
NSLog (#"Date: %#", currentDate);
UEEvent *currentTask = [[UEEvent alloc] initWithName:currentName location:currentLoaction date:currentDate];
[self.upcommingEvents addObject:currentTask];
currentEventInt = currentEventInt + 1;
}
UEDownloaded = YES;
[self.tableView reloadData];
}

Answer 1

i think following code will solve your problem ...
- (void)downloadUEData
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
UERootArray = [[NSArray alloc] initWithContentsOfURL:[NSURL URLWithString:#"http://www.nytrex.webs.com/Linx/upcommingEvents.plist"]];
[self processUEData];
});
}
- (void)processUEData
{
NSLog(#"Array: %#", UERootArray);
//NSLog(#"count %#",count);
NSString *currentName;
NSString *currentLoaction;
NSString *currentDate;
int currentEventInt = 0;
NSArray *currentEventArr = [UERootArray objectAtIndex:0];
while (currentEventArr.count > currentEventInt)
{
currentName = [currentEventArr objectAtIndex:0];
currentLoaction = [currentEventArr objectAtIndex:1];
currentDate = #"7pm 17/11"; //[currentEventArr objectAtIndex:2];
NSLog (#"Title: %#", currentName);
NSLog (#"News: %#", currentLoaction);
NSLog (#"Date: %#", currentDate);
UEEvent *currentTask = [[UEEvent alloc] initWithName:currentName location:currentLoaction date:currentDate];
[self.upcommingEvents addObject:currentTask];
currentEventInt = currentEventInt + 1;
}
UEDownloaded = YES;
dispatch_async(dispatch_get_main_queue(), ^{ // update your UI in main thread
[self.tableView reloadData];
});
}