Issue with Pagintation - ios

Question

I am trying to use the Instagram API for Pagination in my iOS App. However whenever I add my new pictures to my existing array I get this Error:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray insertObject:atIndex:]: mutating method sent to immutable object'
Here is my code on how to get the initial set of Instagram Images:
- (void)fetchInstagramPics {
NSUserDefaults *user = [NSUserDefaults standardUserDefaults];
BOOL *status = [user boolForKey:#"isInstagramLoggedIn"];
if (status) {
[[InstagramClient sharedClient] getPath:#"users/self/feed"
parameters:nil
success:^(AFHTTPRequestOperation *operation, id responseObject) {
// NSLog(#"Response: %#", responseObject);
self.timelineResponse = [responseObject mutableCopy];
[instaPics addObjectsFromArray:responseObject[#"data"]];
[self updateArrays];
[self.tableView reloadData];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Failure: %#", error);
}];
}
dispatch_async(dispatch_get_main_queue(), ^{
[self.tableView reloadData]; });
}
Here is how I am attempting to add more pictures into the instaPics Array:
- (void)nextInstagramPage:(NSIndexPath *)indexPath{
NSDictionary *page = self.timelineResponse[#"pagination"];
NSString *nextPage = page[#"next_url"];
[[InstagramClient sharedClient] getPath:[NSString stringWithFormat:#"%#",nextPage] parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
self.timelineResponse = [responseObject mutableCopy];
[self.timelineResponse addEntriesFromDictionary:responseObject];
[instaPics addObjectsFromArray:responseObject[#"data"]];
[self.tableView reloadData];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Failure: %#", error);
}];
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView.contentOffset.y == roundf(scrollView.contentSize.height-scrollView.frame.size.height)) {
NSLog(#"we are at the endddd");
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self nextInstagramPage:indexPath];
}
}
Here are all the properties defined in the Header file of this class:
#property (strong, nonatomic) NSMutableArray *instaPics;
#property (strong, nonatomic) AFOAuth1Client *twitterClient;
#property (strong, nonatomic) IBOutlet UINavigationItem *navBar;
#property (strong, nonatomic) NSMutableArray *tweets;
//Edit: Now have the construction of the Cells:
if (indexPath.row % 2 == 0) {
static NSString *CellIdentifier = #"TweetCell";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"Background.png"]];
NSDictionary *tweet = tweets[indexPath.row];
return cell;
}else {
static NSString *CellIdentifier = #"InstagramCell";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"Background.png"]];
NSDictionary *entry = instaPics[indexPath.row];
return cell;
}
}

Answer 1

You have to initialize the NSMutableArray, add instaPics = [[NSMutableArray alloc] init]; in fetchInstagramPics