D8: render block in node?

Question

We're migrating some code to D8 and in some of our nodes' body field we used to call PHP code directly with the now defunct module_invoke to render a block in the node before the content.

All the examples I can find explain how to do that in D8 with themes or templates, but I need to render the block inside the node body using PHP code, is there a way to do that?

We already tried:

\Drupal::moduleHandler()->invoke($module, $hook, $args = array())

but it doesn't show the block, presumably because it only takes modules?

From this answer we also tried:

$block = \Drupal\block_content\Entity\BlockContent::load($bid); 
$render = \Drupal::entityTypeManager()->getViewBuilder('block_content')->view($block);

Trying to print or render $render either doesn't show anything or literally prints out an array.

Answer 1

You can do the following:

In hook_preprocess_page() add the following code.

$block_entity = Drupal\block_content\Entity\BlockContent::load(BLOCK_ID);// BLOCK_ID
$block_view = \Drupal::entityTypeManager()->getViewBuilder('block_content')->view($block_entity, 'DISPLAY_VIEW_NAME');
if ($block_view) {
    $variables['page']['my_block'] = $block_view;
}

In your Twig template, print the block with the following code.

{% if page.my_block %}
  {{ page.my_block }}
{% endif %}