function WidgetBase::addMoreAjax

Ajax callback for the "Add another item" button.

This returns the new page content to replace the page content made obsolete by the form submission.

File

core/lib/Drupal/Core/Field/WidgetBase.php, line 322

Class

WidgetBase

Base class for 'Field widget' plugin implementations.

Namespace

Code

public static function addMoreAjax(array $form, FormStateInterface $form_state) {
    $button = $form_state->getTriggeringElement();
    // Go one level up in the form, to the widgets container.
    $element = NestedArray::getValue($form, array_slice($button['#array_parents'], 0, -1));
    // Ensure the widget allows adding additional items.
    if ($element['#cardinality'] != FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED) {
        return;
    }
    // Add a DIV around the delta receiving the Ajax effect.
    $delta = $element['#max_delta'];
    $element[$delta]['#prefix'] = '<div class="ajax-new-content">' . ($element[$delta]['#prefix'] ?? '');
    $element[$delta]['#suffix'] = ($element[$delta]['#suffix'] ?? '') . '</div>';
    return $element;
}