Ajax.php

<?php

namespace Drupal\Core\Render\Element;


/**
 * Provides a render element for adding Ajax to a render element.
 *
 * Holds an array whose values control the Ajax behavior of the element.
 *
 * @ingroup ajax
 *
 * @RenderElement("ajax")
 */
class Ajax extends RenderElement {
    
    /**
     * {@inheritdoc}
     */
    public function getInfo() {
        // By default, we don't want Ajax commands being rendered in the context of
        // an HTML page, so we don't provide defaults for #theme or #theme_wrappers.
        // However, modules can set these properties (for example, to provide an
        // HTML debugging page that displays rather than executes Ajax commands).
        return [
            '#header' => TRUE,
            '#commands' => [],
            '#error' => NULL,
        ];
    }

}