Parse Wordpress Gutenberg blocks

get_block_data.php

<?php
function parseBlocks($blocks, $block_id)
{
  foreach ($blocks as $block) {
    if($block['blockName'] == $block_id) {
      return $block['attrs']['data'];
    }
    if (!empty($block['innerBlocks'])) {
      if ($data = parseBlocks($block['innerBlocks'], $block_id)) {
        return $data;
      }
    }
  }
  return false;
}

function getBlockFromPage($post_id, $block_id)
{
  $post = get_post($post_id);
  if (!$post) return false;
  return parseBlocks(
    parse_blocks($post->post_content),
    $block_id
  );
}

Just use like this:

$block_data = getBlockFromPage($post_id, 'acf/test_name');