Checks whether a candidate allowed value is valid.

Parameters

string $option: The option value entered by the user.

Return value

string The error message if the specified value is invalid, NULL otherwise.

Overrides ListItemBase::validateAllowedValue

File

core/modules/options/src/Plugin/Field/FieldType/ListStringItem.php, line 67

Class

ListStringItem

Plugin implementation of the 'list_string' field type.

Namespace

Drupal\options\Plugin\Field\FieldType

Code

protected static function validateAllowedValue($option) {
  if (mb_strlen($option) > 255) {
    return t('Allowed values list: each key must be a string at most 255 characters long.');
  }
}

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