RenderEvents.php

<?php

namespace Drupal\Core\Render;


/**
 * Defines events for the render system.
 */
final class RenderEvents {
    
    /**
     * Name of the event when selecting a page display variant to use.
     *
     * This event allows you to select a different page display variant to use
     * when rendering a page. The event listener method receives a
     * \Drupal\Core\Render\PageDisplayVariantSelectionEvent instance.
     *
     * @Event
     *
     * @see \Drupal\Core\Render\PageDisplayVariantSelectionEvent
     * @see \Drupal\Core\Render\MainContent\HtmlRenderer
     * @see \Drupal\block\EventSubscriber\BlockPageDisplayVariantSubscriber
     */
    const SELECT_PAGE_DISPLAY_VARIANT = 'render.page_display_variant.select';

}