UITableView insertRowsAtIndexPaths: - iphone

Question

I have a Navigation Controller that contains a uitableview when I press on a row it pops a new view controller on the stack, which is used to display detail information in the detail view it makes a request from the server to get some response information then once the information is returned I use insertRowsAtIndexPaths: to display the information that is returned from the server.
This all works fine the first time, then when i press the back button and select a new row or the same row for viewing the detailed information once I the insertRowsAtIndexPaths: is called i get the following error:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 1. The number of rows contained in an existing section after the update (2) must be equal to the number of rows contained in that section before the update (2), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'
Here is the code for pushing the view on the stack:
VideoDetailViewController_iPhone *nextView = [[VideoDetailViewController_iPhone alloc] initWithNibName:#"VideoDetailViewController_iPhone" bundle:nil withVideo:rowData];
nextView.navController = navController;
[navController pushViewController:nextView animated:YES];
[nextView release];
Here is the code is executed once the information is returned from the server
- (void)fetchVideoDetail:(NSNotification *)notification {
hasLoadedResponses = YES;
NSArray *obj = (NSArray *)[notification object];
responses = [[obj valueForKey:#"responses"] mutableCopy];
//NSLog(#"RESPONSES: %#", responses);
if ([responses count] == 0) {
[tblView reloadData];
return;
}
NSMutableArray *indexes = [[NSMutableArray alloc] init];
int i = 0;
for (NSArray *x in responses) {
if (i > 0) {
//The reason for skipping the first one is because we will change that row once the table refreshes we just need to insert any rows after the first one.
[indexes addObject:[NSIndexPath indexPathForRow:i inSection:1]];
}
i++;
}
//NSLog(#"indexCount: %i", [indexes count]);
[tblView beginUpdates];
[tblView insertRowsAtIndexPaths:indexes withRowAnimation:UITableViewRowAnimationBottom];
[tblView endUpdates];
//[tblView reloadData];
}
Here is the tableView methods:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
if (section == 0) {
return 1;
} else {
if ([responses count] == 0) {
NSLog(#"numberofrowsinsection: 1");
return 1;
} else {
NSLog(#"numberofrowsinsection: %i", [responses count]);
return [responses count];
}
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
VideoCell *cell = (VideoCell *)[tableView dequeueReusableCellWithIdentifier:CellClassName];
if (cell == nil) {
NSArray *topLevelItems = [cellLoader instantiateWithOwner:self options:nil];
cell = [topLevelItems objectAtIndex:0];
}
if (indexPath.section == 0) {
cell.lblTitle.text = [data title];
cell.lblDescription.text = [data videoDescription];
} else {
if ([responses count] == 0) {
if (!hasLoadedResponses) {
cell.lblTitle.text = #"";
cell.lblDescription.text = #"";
} else {
//Responses have been loaded
cell.accessoryType = UITableViewCellAccessoryNone;
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.lblTitle.text = #"No responses to this video";
cell.lblDescription.text = #"Be the first to respond by selecting the \"Set as Destination\" button above";
}
} else {
//Display the response information
cell.lblTitle.text = [[responses objectAtIndex:indexPath.row] valueForKey:#"title"];
cell.lblDescription.text = [[responses objectAtIndex:indexPath.row] valueForKey:#"description"];
}
}
return cell;
}

Answer 1

Your datasource and number of rows are out of sync. When you insert the row, you have to increase the number of rows in the section at the same time. In this case you would have to increase the count of your array responses, which you are using in your numberOfRowsInSection method.