API binding

Populate dynamically blocks (button, image, paragraph and heading), by setting the source, from meta field or php logic.

meta field

<!-- wp:paragraph {
	"metadata":{
		"bindings":{
			"content":{
				"source":"core/post-meta",
				"args":{
					"key":"book-genre"
				}
			}
		}
	}
} -->
<p></p>
<!-- /wp:paragraph -->

register_meta(
    'post',
    'book-genre',
    array(
        'show_in_rest' => true,
        'single'       => true,
        'type'         => 'string',
        'default'      => 'Default text field',
    )
);

php logic

$source_name = 'namespace/name';
$source_properties = array(
	'label'	=> 'Name',
	'get_value_callback' => 'fn',
	'uses_context' => ['postId']
);

register_block_bindings_source(
	string $source_name,
	array $source_properties
);

projectslug_bindings_callback(
	array $source_args, 
	WP_Block $block_instance, 
	string $attribute_name
);

Source: https://make.wordpress.org/core/2024/03/06/new-feature-the-block-bindings-api/