json_to_block.php

<?php
function rsvpBlockDataOutput($block, $post_id) {
    if(empty($block))
        return;
    $attrs = ($block->attrs) ? json_encode($block->attrs) : '';
	if(!empty($block->innerHTML) || (!empty($block->innerBlocks) && sizeof($block->innerBlocks)) ) {
        $output = sprintf('<!-- wp:%s %s -->',$block->blockName,$attrs)."\n";
        if(!empty($block->innerHTML))
		$output .= $block->innerHTML."\n";
        if(!empty($block->innerBlocks) && is_array($block->innerBlocks) && sizeof($block->innerBlocks)) {
            foreach($block->innerBlocks as $innerblock) {
                $output .= jsonBlockDataOutput($innerblock,$post_id);
            }
        }
        $output .= sprintf('<!-- /wp:%s -->',$block->blockName)."\n\n";    
    }
    else 
        $output = sprintf('<!-- wp:%s %s /-->',$block->blockName,$attrs)."\n\n";
    return $output;
}