Update UITextFields from UITableViewCells without reloadind data - ios5

Question

I have a UITableView with custom UITableViewCells , each of them has a UITextField. I assing to each textField a tag with value : indexPath.row + 100.
Well , i want to update each textField for each cell , when i type something in a specific textField. To be more clear , when I type a number, my viewcontroller should make some calculations and then assing the result to all others textFields, and this must be done each time a modify text from textField , let's say i typed 1 (make some calculations and assing result to textFields) , then i type 2 , now number to calculate from, will be 12 and so on.
The issue is that i can reloaddata from tableView without closing keyboar. System will automatically hide UIKeyboard , so reloaddata in this case does not work.
I tried to use an NSMutableArray to store all this textFields but they gets a lot , when adding them from cellForRowAtIndexPath.
How can I update properly all these UITextFields ?

Answer 1

It needs to update only visible cells, but not all of them.
Assuming the content calculation formula is pretty simple:
-(NSString*) textForRowAtIndex:(int)rowIndex
{
return [NSString stringWithFormat:#"%d", startRowValue + rowIndex];
}
And each cell contains UITextField object with tag indexPath.row + 100:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString* cellId = #"cellId";
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:cellId];
if(!cell)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellId] autorelease];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
UITextField* tf = [[[UITextField alloc] initWithFrame:CGRectMake(10, 8, 280, 30)] autorelease];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(textFieldTextDidChange:)
name:UITextFieldTextDidChangeNotification object:tf];
tf.delegate = (id)self;
[cell.contentView addSubview:tf];
}
UITextField* tf = (UITextField*)[[cell.contentView subviews] lastObject];
tf.tag = indexPath.row + 100;
tf.text = [self textForRowAtIndex:indexPath.row];
return cell;
}
Then all visible cells are to be updated in textFieldTextDidChange: method:
-(void) textFieldTextDidChange:(NSNotification*)notification
{
UITextField* editedTextField = (UITextField*)[notification object];
int editedRowIndex = editedTextField.tag - 100;
int editedValue = [editedTextField.text intValue];
startRowValue = editedValue - editedRowIndex;
for (NSIndexPath* indexPath in [self.tableView indexPathsForVisibleRows])
{
if(indexPath.row != editedRowIndex)
{
UITableViewCell* cell = [self.tableView cellForRowAtIndexPath:indexPath];
UITextField* textField = (UITextField*)[cell.contentView viewWithTag:indexPath.row+100];
textField.text = [self textForRowAtIndex:indexPath.row];
}
}
}
Lets have 50 cells:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 50;
}
And lets hide keyboard when finish editing:
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
[textField resignFirstResponder];
return YES;
}
Enjoy!