Alter a custom block depending on custom block type

Question

I need to alter all the blocks of custom type 'my_custom_block_type' that get displayed on my site. In order to achieve this, i added a custom prerender in which i filter on the block bundle :

function my_module_block_view_alter(array &$build, \Drupal\Core\Block\BlockPluginInterface $block) {
  $build['#pre_render'][] = '_custom_block_custom_prerender';
}

function _custom_block_custom_prerender(array $build) {
  if ($build['content']['#block_content']) {
    $block_bundle = $build['content']['#block_content']->bundle();

    if ($build['content']['#block_content']->bundle() === 'my_custom_block_type') {
      // do your thing here
    }
  }
  return $build;
}

I think it's not the most elegant way to do this.

I tried to enhance this, but i did not manage, after several attempts, to retrieve the block type directly inside a hook_block_view_alter or a hook_block_build_alter ...

function hook_block_view_alter(array &$build, \Drupal\Core\Block\BlockPluginInterface $block) {
  // things
}
function hook_block_build_alter(array &$build, \Drupal\Core\Block\BlockPluginInterface $block) {
  // stuff
}

Is there a way to easily get the custom block type inside those two hooks ?

Answer 1

Try hook_ENTITY_TYPE_view()/hook_ENTITY_TYPE_view_alter(), that gives you the block_content $entity as an argument, just like hook_node_view().