wp_register_shadow_support() │ WP 6.3.0

Registers the style and shadow block attributes for block types that support it.

Internal function — this function is designed to be used by the kernel itself. It is not recommended to use this function in your code.

No Hooks.

Returns

null. Nothing (null).

Usage

wp_register_shadow_support( $block_type );
$block_type(WP_Block_Type) (required)
Block Type.

Changelog

Since 6.3.0 Introduced.

wp_register_shadow_support() code WP 6.9.1

wp-includes/block-supports/shadow.php 
function wp_register_shadow_support( $block_type ) {
	$has_shadow_support = block_has_support( $block_type, 'shadow', false );

	if ( ! $has_shadow_support ) {
		return;
	}

	if ( ! $block_type->attributes ) {
		$block_type->attributes = array();
	}

	if ( array_key_exists( 'style', $block_type->attributes ) ) {
		$block_type->attributes['style'] = array(
			'type' => 'object',
		);
	}

	if ( array_key_exists( 'shadow', $block_type->attributes ) ) {
		$block_type->attributes['shadow'] = array(
			'type' => 'string',
		);
	}
}