Check what Gutenberg blocks are in post_content

Question

I'm working on a design that has different styling if a certain Gutenberg block is present on a page. In other words, if the first block is a custom built Gutenberg block, the post_title is rendered elsewhere due to design choices made.

Is there any function in WordPress to get a list of all Gutenberg blocks present in the post_content?

Answer 1

WordPress 5.0+ has a function for this: parse_blocks(). To see if the first block in the post is the Heading block, you'd do this:

$post = get_post(); 

if ( has_blocks( $post->post_content ) ) {
    $blocks = parse_blocks( $post->post_content );

    if ( $blocks[0]['blockName'] === 'core/heading' ) {
    }
}

Answer 2

The solution I'm using as of writing check the post_content for the Gutenberg HTML comments. Due to future Gutenberg changes this might not work in the future.

<?php    
$post_content = get_the_content( get_the_ID() ); // Get the post_content
preg_match_all('<!-- /wp:(.*?) -->', $post_content, $blocks); // Get all matches in between <!-- /wp: --> strings

// $blocks[1] contains the names of all the blocks present in the post_content
if ( in_array( 'heading', $blocks[1] ) ) {
    // Post content contains a wp:heading block
}
else {
    // Post content does not contain a wp:heading block
}

Answer 3

As of the release of 5.0 these functions have been deprecated with Gutenberg now integrated into the core. I imagine, but have not confirmed that these functions still exist in the Gutenberg standalone plugin.

Instead of gutenberg_content_has_blocks use has_blocks

Instead of gutenberg_parse_blocks use parse_blocks