Blocks: Add block bindings registry class

src/wp-includes/class-wp-block-bindings-registry.php

@@ -0,0 +1,194 @@
+<?php
+/**
+ * Block Bindings API: WP_Block_Bindings_Registry class.
+ *
+ * Supports overriding content in blocks by connecting them to different sources.
+ *
+ * @package WordPress
+ * @subpackage Block Bindings
+ * @since 6.5.0
+ */
+
+/**
+ * Core class used for interacting with block binding sources.
+ *
+ *  @since 6.5.0
+ */
+final class WP_Block_Bindings_Registry {
+
+	/**
+	 * Holds the registered block bindings sources, keyed by source identifier.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @var array
+	 */
+	private $sources = array();
+
+	/**
+	 * Container for the main instance of the class.
+	 *
+	 * @since 6.5.0
+	 * @var WP_Block_Bindings_Registry|null
+	 */
+	private static $instance = null;
+
+	/**
+	 * Registers a new block binding source.
+	 *
+	 * Sources are used to override block's original attributes with a value
+	 * coming from the source. Once a source is registered, it can be used by a
+	 * block by setting its `metadata.bindings` attribute to a value that refers
+	 * to the source.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string   $source_name       The name of the source.
+	 * @param array    $source_properties {
+	 *     The array of arguments that are used to register a source.
+	 *
+	 *     @type string   $label              The label of the source.
+	 *     @type callback $get_value_callback A callback executed when the source is processed during block rendering.
+	 *                                        The callback should have the following signature:
+	 *
+	 *                                        `function ($source_args, $block_instance,$attribute_name): mixed`
+	 *                                            - @param array    $source_args    Array containing source arguments
+	 *                                                                              used to look up the override value,
+	 *                                                                              i.e. {"key": "foo"}.
+	 *                                            - @param WP_Block $block_instance The block instance.
+	 *                                            - @param string   $attribute_name The name of an attribute .
+	 *                                        The callback has a mixed return type; it may return a string to override
+	 *                                        the block's original value, null, false to remove an attribute, etc.
+	 * }
+	 * @return array|false Source when the registration was successful, or `false` on failure.
+	 */
+	public function register( $source_name, array $source_properties ) {
+		if ( ! is_string( $source_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Block binding source name must be a string.' ),
+				'6.5.0'
+			);
+			return false;
+		}
+
+		if ( preg_match( '/[A-Z]+/', $source_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Block binding source names must not contain uppercase characters.' ),
+				'6.5.0'
+			);
+			return false;
+		}
+
+		$name_matcher = '/^[a-z0-9-]+\/[a-z0-9-]+$/';
+		if ( ! preg_match( $name_matcher, $source_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Block binding source names must contain a namespace prefix. Example: my-plugin/my-custom-source' ),
+				'6.5.0'
+			);
+			return false;
+		}
+
+		if ( $this->is_registered( $source_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				/* translators: %s: Block binding source name. */
+				sprintf( __( 'Block binding source "%s" already registered.' ), $source_name ),
+				'6.5.0'
+			);
+			return false;
+		}
+
+		$source = array_merge(
+			array( 'name' => $source_name ),
+			$source_properties
+		);
+
+		$this->sources[ $source_name ] = $source;
+
+		return $source;
+	}
+
+	/**
+	 * Unregisters a block binding source.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string $source_name Block binding source name including namespace.
+	 * @return array|false The unregistred block binding source on success and `false` otherwise.
+	 */
+	public function unregister( $source_name ) {
+		if ( ! $this->is_registered( $source_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				/* translators: %s: Block binding source name. */
+				sprintf( __( 'Block binding "%s" not found.' ), $source_name ),
+				'6.5.0'
+			);
+			return false;
+		}
+
+		$unregistered_source = $this->sources[ $source_name ];
+		unset( $this->sources[ $source_name ] );
+
+		return $unregistered_source;
+	}
+
+	/**
+	 * Retrieves the list of all registered block bindings sources.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @return array The array of registered sources.
+	 */
+	public function get_all_registered() {
+		return $this->sources;
+	}
+
+	/**
+	 * Retrieves a registered block bindings source.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string $source_name The name of the source.
+	 * @return array|null The registered block binding source, or `null` if it is not registered.
+	 */
+	public function get_registered( $source_name ) {
+		if ( ! $this->is_registered( $source_name ) ) {
+			return null;
+		}
+
+		return $this->sources[ $source_name ];
+	}
+
+	/**
+	 * Checks if a block binding source is registered.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string $source_name The name of the source.
+	 * @return bool `true` if the block binding source is registered, `false` otherwise.
+	 */
+	public function is_registered( $source_name ) {
+		return isset( $this->sources[ $source_name ] );
+	}
+
+	/**
+	 * Utility method to retrieve the main instance of the class.
+	 *
+	 * The instance will be created if it does not exist yet.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @return WP_Block_Bindings_Registry The main instance.
+	 */
+	public static function get_instance() {
+		if ( null === self::$instance ) {
+			self::$instance = new self();
+		}
+
+		return self::$instance;
+	}
+}

src/wp-settings.php

@@ -330,6 +330,7 @@
 require ABSPATH . WPINC . '/sitemaps/providers/class-wp-sitemaps-taxonomies.php';
 require ABSPATH . WPINC . '/sitemaps/providers/class-wp-sitemaps-users.php';
 require ABSPATH . WPINC . '/class-wp-block-editor-context.php';
+require ABSPATH . WPINC . '/class-wp-block-bindings-registry.php';
 require ABSPATH . WPINC . '/class-wp-block-type.php';
 require ABSPATH . WPINC . '/class-wp-block-pattern-categories-registry.php';
 require ABSPATH . WPINC . '/class-wp-block-patterns-registry.php';