TWRequest code works but very slow to show? - xcode

Question

I'm working with TWrequest to display my twitter lists in a tableview. The following code works. The problem is it is very slow to update the table. I am NSlogging the request response (which happens very quickly), I am also looping through each list and adding the list 'name' to an array (which again, happens very quickly <1s). But for some inexplicable reason, the table takes roughly a further 4 seconds or so to update.
Why is this taking so long for the table to reload? The problem is not parsing the response (because I can see with nslog this happens pretty quick), it's taking a long time to display in the table? Help very much appreciated!
-(IBAction)getLists{
// First, we need to obtain the account instance for the user's Twitter account
ACAccountStore *store = [[ACAccountStore alloc] init];
ACAccountType *twitterAccountType = [store accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
// Request permission from the user to access the available Twitter accounts
[store requestAccessToAccountsWithType:twitterAccountType withCompletionHandler:^(BOOL granted, NSError *error) {
if (!granted) {
// The user rejected your request
NSLog(#"User rejected access to the account.");
}
else {
// Grab the available accounts
twitterAccounts = [store accountsWithAccountType:twitterAccountType];
if ([twitterAccounts count] > 0) {
// Use the first account for simplicity
ACAccount *account = [twitterAccounts objectAtIndex:0];
// Now make an authenticated request to our endpoint
NSMutableDictionary *params = [[NSMutableDictionary alloc] init];
//[params setObject:#"1" forKey:#"include_entities"];
// The endpoint that we wish to call
NSURL *url = [NSURL URLWithString:#"http://api.twitter.com/1.1/lists/list.json"];
// Build the request with our parameter
TWRequest *request = [[TWRequest alloc] initWithURL:url parameters:params requestMethod:TWRequestMethodGET];
// Attach the account object to this request
[request setAccount:account];
[request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
if (!responseData) {
// inspect the contents of error
NSLog(#"error = %#", error);
}
else {
NSError *jsonError;
NSArray *timeline = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableLeaves error:&jsonError];
if (timeline) {
// at this point, we have an object that we can parse
NSLog(#"timeline = %#", timeline);
for (NSDictionary *element in timeline) {
NSString *listName = [element valueForKey:#"name"];
[listsArray addObject:listName];
}
[listsTable reloadData];
}
else {
// inspect the contents of jsonError
NSLog(#"jsonerror = %#", jsonError);
}
}
}];
}
}
}];
}

Answer 1

Sorry, just came across this post. If you haven't found a solution yet, hopefully this will help.
I believe that performRequestWithHandler can be called on any thread, so UI changes should be dispatched to the main thread.
dispatch_async(dispatch_get_main_queue(), ^{
//update UI here
});
Or in the case of reloading table data you can use:
[self.tableView performSelectorOnMainThread:#selector(reloadData) withObject:nil waitUntilDone:NO];