WP_Block_Bindings_Registry

17final class WP_Block_Bindings_Registry {18 19	/**20	 * Holds the registered block bindings sources, keyed by source identifier.21	 *22	 * @since 6.5.023	 * @var WP_Block_Bindings_Source[]24	 */25	private $sources = array();26 27	/**28	 * Container for the main instance of the class.29	 *30	 * @since 6.5.031	 * @var WP_Block_Bindings_Registry|null32	 */33	private static $instance = null;34 35	/**36	 * Supported source properties that can be passed to the registered source.37	 *38	 * @since 6.5.039	 * @var string[]40	 */41	private $allowed_source_properties = array(42		'label',43		'get_value_callback',44		'uses_context',45	);46 47	/**48	 * Registers a new block bindings source.49	 *50	 * This is a low-level method. For most use cases, it is recommended to use51	 * the `register_block_bindings_source()` function instead.52	 *53	 * @see register_block_bindings_source()54	 *55	 * Sources are used to override block's original attributes with a value56	 * coming from the source. Once a source is registered, it can be used by a57	 * block by setting its `metadata.bindings` attribute to a value that refers58	 * to the source.59	 *60	 * @since 6.5.061	 *62	 * @param string $source_name       The name of the source. It must be a string containing a namespace prefix, i.e.63	 *                                  `my-plugin/my-custom-source`. It must only contain lowercase alphanumeric64	 *                                  characters, the forward slash `/` and dashes.65	 * @param array  $source_properties {66	 *     The array of arguments that are used to register a source.67	 *68	 *     @type string   $label              The label of the source.69	 *     @type callable $get_value_callback A callback executed when the source is processed during block rendering.70	 *                                        The callback should have the following signature:71	 *72	 *                                        `function( $source_args, $block_instance, $attribute_name ): mixed`73	 *                                            - @param array    $source_args    Array containing source arguments74	 *                                                                              used to look up the override value,75	 *                                                                              i.e. {"key": "foo"}.76	 *                                            - @param WP_Block $block_instance The block instance.77	 *                                            - @param string   $attribute_name The name of the target attribute.78	 *                                        The callback has a mixed return type; it may return a string to override79	 *                                        the block's original value, null, false to remove an attribute, etc.80	 *     @type string[] $uses_context       Optional. Array of values to add to block `uses_context` needed by the source.81	 * }82	 * @return WP_Block_Bindings_Source|false Source when the registration was successful, or `false` on failure.83	 */84	public function register( string $source_name, array $source_properties ) {85		if ( ! is_string( $source_name ) ) {86			_doing_it_wrong(87				__METHOD__,88				__( 'Block bindings source name must be a string.' ),89				'6.5.0'90			);91			return false;92		}93 94		if ( preg_match( '/[A-Z]+/', $source_name ) ) {95			_doing_it_wrong(96				__METHOD__,