Editor: Add registry for block binding sources

It is part of the sync from the Gutenberg plugin that introduces the registry for block binding sources required for the new Block Bindings API: WordPress/gutenberg#54536.

See #60282.
Props czapla, artemiosans, santosguillamot, sc0ttkclark, lgladdy, talldanwp, swissspidy, youknowriad, fabiankaegy.



git-svn-id: https://develop.svn.wordpress.org/trunk@57373 602fd350-edb4-49c9-b593-d223f7449a82

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';