Add new items to UITableView without replacing old items - ios

Question

I intended to add items to a UITableView when this method was called. New items are successfully added (but there's a problem, mentioned below), but I think its odd because I thought "begin updates" to "end updates" was supposed to handle this (Inserting a new row). The initial if condition I had put in never ran so the whole area never got executed. I only realized this recently and updated the condition to what it is now. Now the if block get executed and it crashes the app.
When it is commented out like it is now... New items are added but the newNameOfItem replaces any existing cell labels.
I would like this to add x(newNumberOfItems) new items preferably into a new section each time its called. How can I achieve this?
- (void)addNew:(NSString *)newNumberOfItems :(NSString *)newNameOfItem
{
if(!self.numberOfRows){
NSLog(#"Initially no of rows = %d", self.numberOfRows);
self.numberOfRows = [self.numberOfItems intValue];
NSLog(#"Then no of rows = %d", self.numberOfRows);
}
else
{
self.numberOfRows = self.numberOfRows + [newNumberOfItems intValue];
NSLog(#"New no rows = %d", self.numberOfRows);
}
NSLog(#"run = %d", self.run);
Begin updates if statement ...
/*if(self.secondRun){
NSLog(#"run = %d it it", self.run);
[self.tableView beginUpdates];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:self.numberOfRows-[newnumberOfItems intValue] inSection:0];
[self.tableView insertRowsAtIndexPaths:#[indexPath]withRowAnimation:UITableViewRowAnimationBottom];
[self.tableView endUpdates];
}
*/
[self.tableView reloadData];
}
...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"UITableViewCell" forIndexPath:indexPath];
cell.textLabel.text = self.nameOfItem;
return cell;
}
...
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.numberOfRows;
}

Answer 1

If you want to add new items to a new section every time you call -addNew…, you should create an NSMutableArray of sections where each member is an array of objects representing row data (in this case seems like you'd want NSStrings that represent the item's name. The structure would look something like:
mySections = #[ #[#"section 0 row 0 name", #"section 0 row 1 name", …], #[#"section 1 row 0 name", #"section 1 row 1 name", …], …]
Then in numberOfRowsInSection: return mySection[indexPath.section].count.
Each label has the same value because you're setting every single label for every cell that you dequeue to self.nameOfItem. It's doing exactly what you told it to do. If your intent is to set a different text for every section/row, you have to fetch that text from somewhere. If you created a mySections array as above, you could:
cell.textLabel.text = mySections[indexPath.section][indexPath.row] ;
A note about -addNew:…: simply adding new items to your mySections array will not cause the tableview to update. As you know above, [self.tableView reloadData] will do this for you. However, it will reload the entire table instead of just updating the rows that you added. To do this more efficiently (and with a nice animation), you instead use [self.tableView beginUpdates/endUpdates]. In the case above, where you're adding entire sections and not just rows, you should use insertSections:withRowAnimation:.