function MachineName::validateMachineName

Form element validation handler for machine_name elements.

Note that #maxlength is validated by _form_validate() already.

This checks that the submitted value:

• Does not contain the replacement character only.
• Does not contain disallowed characters.
• Is unique; i.e., does not already exist.
• Does not exceed the maximum length (via #maxlength).
• Cannot be changed after creation (via #disabled).

File

core/lib/Drupal/Core/Render/Element/MachineName.php, line 246

Class

MachineName

Provides a machine name render element.

Namespace

Code

public static function validateMachineName(&$element, FormStateInterface $form_state, &$complete_form) {
    // Verify that the machine name not only consists of replacement tokens.
    if (preg_match('@^' . $element['#machine_name']['replace'] . '+$@', $element['#value'])) {
        $form_state->setError($element, t('The machine-readable name must contain unique characters.'));
    }
    // Verify that the machine name contains no disallowed characters.
    if (preg_match('@' . $element['#machine_name']['replace_pattern'] . '@', $element['#value'])) {
        if (!isset($element['#machine_name']['error'])) {
            // Since a hyphen is the most common alternative replacement character,
            // a corresponding validation error message is supported here.
            if ($element['#machine_name']['replace'] == '-') {
                $form_state->setError($element, t('The machine-readable name must contain only lowercase letters, numbers, and hyphens.'));
            }
            else {
                $form_state->setError($element, t('The machine-readable name must contain only lowercase letters, numbers, and underscores.'));
            }
        }
        else {
            $form_state->setError($element, $element['#machine_name']['error']);
        }
    }
    // Verify that the machine name is unique. If the value matches the initial
    // default value then it does not need to be validated as the machine name
    // element assumes the form is editing the existing value.
    $initial_values = $form_state->get('machine_name.initial_values') ?: [];
    if (!array_key_exists($element['#name'], $initial_values) || $initial_values[$element['#name']] !== $element['#value']) {
        $function = $element['#machine_name']['exists'];
        if (call_user_func($function, $element['#value'], $element, $form_state)) {
            $form_state->setError($element, t('The machine-readable name is already in use. It must be unique.'));
        }
    }
}