: str_replace(): Passing null to parameter #2 ($replace) of type array|string is deprecated in
* Blocks API: WP_Block_Styles_Registry class
* Class used for interacting with block styles.
#[AllowDynamicProperties]
final class WP_Block_Styles_Registry {
* Registered block styles, as `$block_name => $block_style_name => $block_style_properties` multidimensional arrays.
private $registered_block_styles = array();
* Container for the main instance of the class.
* @var WP_Block_Styles_Registry|null
private static $instance = null;
* Registers a block style for the given block type.
* If the block styles are present in a standalone stylesheet, register it and pass
* its handle as the `style_handle` argument. If the block styles should be inline,
* use the `inline_style` argument. Usually, one of them would be used to pass CSS
* styles. However, you could also skip them and provide CSS styles in any stylesheet
* @since 6.6.0 Added ability to register style across multiple block types along with theme.json-like style data.
* @link https://developer.wordpress.org/block-editor/reference-guides/block-api/block-styles/
* @param string|string[] $block_name Block type name including namespace or array of namespaced block type names.
* @param array $style_properties {
* Array containing the properties of the style.
* @type string $name The identifier of the style used to compute a CSS class.
* @type string $label A human-readable label for the style.
* @type string $inline_style Inline CSS code that registers the CSS class required
* @type string $style_handle The handle to an already registered style that should be
* enqueued in places where block styles are needed.
* @type bool $is_default Whether this is the default style for the block type.
* @type array $style_data Theme.json-like object to generate CSS from.
* @return bool True if the block style was registered with success and false otherwise.
public function register( $block_name, $style_properties ) {
if ( ! is_string( $block_name ) && ! is_array( $block_name ) ) {
__( 'Block name must be a string or array.' ),
if ( ! isset( $style_properties['name'] ) || ! is_string( $style_properties['name'] ) ) {
__( 'Block style name must be a string.' ),
if ( str_contains( $style_properties['name'], ' ' ) ) {
__( 'Block style name must not contain any spaces.' ),
$block_style_name = $style_properties['name'];
$block_names = is_string( $block_name ) ? array( $block_name ) : $block_name;
foreach ( $block_names as $name ) {
if ( ! isset( $this->registered_block_styles[ $name ] ) ) {
$this->registered_block_styles[ $name ] = array();
$this->registered_block_styles[ $name ][ $block_style_name ] = $style_properties;
* Unregisters a block style of the given block type.
* @param string $block_name Block type name including namespace.
* @param string $block_style_name Block style name.
* @return bool True if the block style was unregistered with success and false otherwise.
public function unregister( $block_name, $block_style_name ) {
if ( ! $this->is_registered( $block_name, $block_style_name ) ) {
/* translators: 1: Block name, 2: Block style name. */
sprintf( __( 'Block "%1$s" does not contain a style named "%2$s".' ), $block_name, $block_style_name ),
unset( $this->registered_block_styles[ $block_name ][ $block_style_name ] );
* Retrieves the properties of a registered block style for the given block type.
* @param string $block_name Block type name including namespace.
* @param string $block_style_name Block style name.
* @return array Registered block style properties.
public function get_registered( $block_name, $block_style_name ) {
if ( ! $this->is_registered( $block_name, $block_style_name ) ) {
return $this->registered_block_styles[ $block_name ][ $block_style_name ];
* Retrieves all registered block styles.
* @return array[] Array of arrays containing the registered block styles properties grouped by block type.
public function get_all_registered() {
return $this->registered_block_styles;
* Retrieves registered block styles for a specific block type.
* @param string $block_name Block type name including namespace.
* @return array[] Array whose keys are block style names and whose values are block style properties.
public function get_registered_styles_for_block( $block_name ) {
if ( isset( $this->registered_block_styles[ $block_name ] ) ) {
return $this->registered_block_styles[ $block_name ];
* Checks if a block style is registered for the given block type.
* @param string $block_name Block type name including namespace.
* @param string $block_style_name Block style name.
* @return bool True if the block style is registered, false otherwise.
public function is_registered( $block_name, $block_style_name ) {
return isset( $this->registered_block_styles[ $block_name ][ $block_style_name ] );
* Utility method to retrieve the main instance of the class.
* The instance will be created if it does not exist yet.
* @return WP_Block_Styles_Registry The main instance.
public static function get_instance() {
if ( null === self::$instance ) {
self::$instance = new self();