How to loop Through each UITextfield of a Section?

Question

Earlier today I asked a question about Textfields. Now I am stuck at how to loop through each UITextFields.

How Do you loop Through each UITextfield of a Section ?

Here is my code so far:

- (IBAction)ForwardReport:(id)sender {
    NSLog(@"PRESSED");
    for (UITableViewCell *cell in [self.tableView.indexPathsForVisibleRows]) {
        if ([cell isKindOfClass:[UITextField class]]) {
            UITextField *textField = (UITextField *)cell;
            NSLog(@"UITEXTFIELD TEXT = %@", textField.text);
        }
    }
}

I tried following this answer but Unfortunately my code wouldn't compile.

I am not sure how to access the section 1 (second section) when outside of UItableView Delegate.

I would like to iterate through each UITextfield, and retrieve its text value.

Please advice:

Here's a screen shot

I guess my other option would be to create IBoutlets for each field, and have a bunch of if/else statement, but it sound kind of messy....

Answer 1

You should search UITextField not in cells but in cell's subviews.

Try following

- (IBAction)ForwardReport:(id)sender {
    NSLog(@"PRESSED");
    for (UITableViewCell *cell in self.tableView.visibleCells) {
        for (UIView *subview in [cell.contentView subviews])
            if ([subview isKindOfClass:[UITextField class]]) {
                UITextField *textField = (UITextField *) subview;
                NSLog(@"UITEXTFIELD TEXT = %@", textField.text);
            }
        }
    }
}

Answer 2

My suggestion is not doing that. You cannot rely on the content of a UITextField that is embedded in a cell of a tableView, due to reusability.

Your view controller should be directly tied to the model, thus, changing the text within a textField should update your model immediately, so, when you scroll and a cell gets reused, the proper value is assigned. And when you hit "forward" you just query the content of the model (which, by all means, could probably be a simple NSMutableArray).

Let's add an NSMutableArray with as many empty strings as there will be textFields (for example 5):

- (instancetype)initWithWhatever...
{
    self = [super initWithWhatever];

    if (self)
    {
        _textFieldValues = [NSMutableArray arrayWithCapacity:5];

        for (NSInteger i=0; i < 5; i++)
        {
            _textFieldValues[i] = @"";
        }
    }       

    return self;
}

Make sure every textfield points back to your viewController, on cellForRowAtIndexPath:.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    ...        

    myCell.textField.text     = _textFieldValues[indexPath.row];
    myCell.textField.tag      = 100 + indexPath.row;
    myCell.textField.delegate = self;

    return myCell
}

The tag is there to identify each cell, other option is to make your own UITextField subclass or use a custom setValueForKey:.

Whatever you pick, when you get the delegate method (UITextFieldDelegate), check against your preferred method, tag in my case:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSString *replaced = [textField.text stringByReplacingCharactersInRange:range withString:string];

    _textFieldValues[(textField.tag - 100)] = replaced;

    return YES;
}

That will keep the model up to date always, and you don't need to iterate text fields, just over the array:

// Method that gets called when hitting forward
- (IBOutlet)didPressForwardButton:(UIButton*)sender
{
    for (NSString *text in _textFieldValues)
    {
        NSLog(@"UITEXTFIELD TEXT = %@", text);
    }
}

Lesson: When working with a UITableView you should be always mapping what's on the view to what's on the model, and update immediately, you cannot rely on the view to hold the data. In fact, this should extend to anything you do in iOS, views are for shows. If you cannot modify the real model immediately, you would have to encapsulate it in a "transaction" intermediary object and then update the real model.

Answer 3

In AVT's answer, get rid of the brackets around self.tableView.visibleCells in the for loop. Then it would read

for (UITableViewCell *cell in self.tableView.visibleCells)

Then the next for loop should really be using the cell's content view's subviews:

for (UIView *subview in [cell.contentView subviews])

However, these are minor issues.

There is a more important design issue. You should not be looping through the currently visible cells. Table view cells are transient. If the user scrolls a table view cell off the screen, it's contents are discarded - and lost.

You should collect information from the view objects in a cell as the user enters that information: Switches and segmented controls should be hooked to outlets that immediately save the users changes into the data model. Likewise with text fields, you need to set up a delegate, and collect the user's input as soon as he's done entering it and save it to the data model.

Answer 4

There are two errors in your code.

First problem:

UITableViewCell *cell in [self.tableView.indexPathsForVisibleRows]

won't work because self.tableView.indexPathsForVisibleRows returns an array of indexPaths and not a UITableViewCell. Try this:

- (IBAction)ForwardReport:(id)sender {
    NSLog(@"PRESSED");
    for (NSIndexPath *indexPath in [self.tableView indexPathsForVisibleRows]) {
        UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];

        ...

    }
}

Second problem:

UITextField *textField = (UITextField *)cell;

UITextField is not a subclass of UITableViewCell and hence you cannot cast a table view cell as a textField. Instead you have to iterate over all subviews contained in your cell. So the whole method would be:

- (IBAction)ForwardReport:(id)sender {
    NSLog(@"PRESSED");
    for (NSIndexPath *indexPath in [self.tableView indexPathsForVisibleRows]) {
        UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
        for (UIView *subview in cell.subviews)
            if ([subview isKindOfClass:[UITextField class]]) {
                UITextField *textField = (UITextField *)subview;
                NSLog(@"UITEXTFIELD TEXT = %@", textField.text);
            }
        }
    }
}

(Note: I have not yet tested this code.)