Set error message only on errornous field(s) when validating multiple instances of the same field

John Doe

7/21/24, 2:17 AM

I have a form where the users can add one or more "units".
I want to validate and return an error message on the problematic field when the unit does not have a value "leader"
With the below code, an error message appears under all unit fields even if some inputs do not have error.

How can I add the error message only to the problematic field? Here's my attempt so far.


    // Foreach $values['unit'], check if this field has the key
    // "leader". If not, add an error message and require the user
    // to select a sub field which has area leaders.
    if ($values['unit']) {
      foreach ($values['unit'] as $unit) {
        if (empty($unit["leader"])) {
          $form_state->setErrorByName('unit',
            new TranslatableMarkup('Please select a unit with a leader.'));
          break;
        }
      }
    }

1 + 1

forms

Jaypan

7/21/24, 2:51 AM

Is this an a form validation handler or an element validation handler or somewhere else?

Score:2

Drupal

Jaypan

7/21/24, 2:54 AM

Assuming the code is a form validation handler, you should be able to do something like this:

if ($values['unit']) {
  foreach ($values['unit'] as $index => $unit) {
    if (empty($unit['leader'])) {
      $form_state->setError($form['unit']['widget'][$index],t('Please select a unit with a leader.'));
    }
  }
}

However, if the unit element of the form is a child of a tree, then the first argument to setError() must be updated to the actual location of the element within the $form array.

+ 1

John Doe

7/21/24, 4:26 AM

Thank you so much for pointing me to `setError`! I notice that the $values array has an item "add more", which holds information for the "add more" button. After adding `array_pop($units);` to remove this "add more" array, your code works. Really appreciate your time!

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Set error message only on errornous field(s) when validating multiple instances of the same field

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