eventDispatcher example

  public function toRenderArray(array $contexts = [], $in_preview = FALSE) {
    $event = new SectionComponentBuildRenderArrayEvent($this, $contexts, $in_preview);
    $this->eventDispatcher()->dispatch($event, LayoutBuilderEvents::SECTION_COMPONENT_BUILD_RENDER_ARRAY);
    $output = $event->getBuild();
    $event->getCacheableMetadata()->applyTo($output);
    return $output;
  }

  /** * Gets any arbitrary property for the component. * * @param string $property * The property to retrieve. * * @return mixed * The value for that property, or NULL if the property does not exist. */