append items to UITableView or UICollectionView

// from stack overflow with UITableView

// build the index paths for insertion

    // since you're adding to the end of datasource, the new rows will start at count

    NSMutableArray*indexPaths =[NSMutableArray array];

    NSInteger currentCount = self.datasource.count;

    for(int i =0; i < dataToAdd.count; i++)

    {

        [indexPaths addObject:[NSIndexPath indexPathForRow:currentCount+i inSection:0]];

    }

    // do the insertion

    [self.dataSource addObjects:dataToAdd];

    // tell the table view to update (at all of the inserted index paths)

    [self.tableView beginUpdates];

    [self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationTop];

    [self.tableView endUpdates];

// in my real code with UICollectionView

- (void)getMoreServerData

{

// 새로운 아이템을 컬렉션의 끝에 추가

NSMutableArray *indexPaths = [NSMutableArray array];

                NSInteger currentCount = items.count;

                for (int i = 0; i < model.storesModelArray.count; i++) {

                    [indexPaths addObject:[NSIndexPath indexPathForRow:currentCount+i inSection:0]];

                }

                [items addObjectsFromArray:model.storesModelArray];

                [self.collectionView insertItemsAtIndexPaths:indexPaths];

}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {

// 리스트의 마지막에 도착한 경우 attach data

    if (scrollOffset + scrollView.frame.size.height == scrollView.contentSize.height)

    {

        [self getMoreServerData];

    }

}