dispatch_queue_t and TableView - ios

Question

I'm a noobie in the Objective-C language, and I have a little problem.
In fact, I have 2 TableViews, and when I go from one to the other I parse some XML from the internet. The parsing is doing well, but I wanted to add an UIActivityIndicatorView between those 2 views to tell to the user that something is loading.
So, to do that, I wanted to do the parsing in another thread and show the UIActivityIndicatorView in the main thread. So here's my code :
- (void)viewDidLoad
{
[super viewDidLoad];
UIActivityIndicatorView *activityIndicator;
activityIndicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activityIndicator.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
activityIndicator.center = self.view.center;
[self.view addSubview: activityIndicator];
activityIndicator.startAnimating;
dispatch_queue_t queue = dispatch_get_global_queue(0,0);
dispatch_async(queue, ^{
NSError *error = nil;
// we will put parsed data in an a array
titles = [[NSMutableArray alloc] init];
urls = [[NSMutableArray alloc] init];
CXMLDocument *rssParser = [[CXMLDocument alloc] initWithContentsOfURL:[NSURL URLWithString:_emissionSelectionnee] options:0 error:&error];
NSArray *nodes = NULL;
nodes = [rssParser nodesForXPath:#"//rss/channel/item/title" error:nil];
for (CXMLElement *title in nodes) {
[titles addObject:[title stringValue]];
}
nodes = NULL;
nodes = [rssParser nodesForXPath:#"//rss/channel/item/enclosure" error:nil];
for (CXMLElement *url in nodes) {
[urls addObject:[[url attributeForName:#"url"] stringValue]];
}
dispatch_sync(dispatch_get_main_queue(), ^{
activityIndicator.stopAnimating;
});
}
}
So now, the UIActivityIndicator shows up, but the cells are empty.. When I do not use the dispatch_queue_t, it works well..
Does someone have an idea?
Thank you in advance!

Answer 1

You need to reload your Table view (in the same block where you hide the activity indicator):
[self.tableView reloadData]