/**
* Renders a placeholder, and just that placeholder.
*
* BigPipe renders placeholders independently of the rest of the content, so
* it needs to be able to render placeholders by themselves.
*
* @param string $placeholder
* The placeholder to render.
* @param array $placeholder_render_array
* The render array associated with that placeholder.
*
* @return array
* The render array representing the rendered placeholder.
*
* @see \Drupal\Core\Render\RendererInterface::renderPlaceholder()
*/
protected function renderPlaceholder($placeholder, array $placeholder_render_array)
{
$elements = ['#markup' => $placeholder, '#attached' => ['placeholders' => [$placeholder => $placeholder_render_array]]];
return $this->renderer->renderPlaceholder($placeholder, $elements);
}
