diff -r c7c34916027a -r 177826044cd9 wp/wp-includes/class-wp-block-type-registry.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-block-type-registry.php	Mon Oct 14 18:28:13 2019 +0200
@@ -0,0 +1,173 @@
+<?php
+/**
+ * Blocks API: WP_Block_Type_Registry class
+ *
+ * @package WordPress
+ * @subpackage Blocks
+ * @since 5.0.0
+ */
+
+/**
+ * Core class used for interacting with block types.
+ *
+ * @since 5.0.0
+ */
+final class WP_Block_Type_Registry {
+	/**
+	 * Registered block types, as `$name => $instance` pairs.
+	 *
+	 * @since 5.0.0
+	 * @var WP_Block_Type[]
+	 */
+	private $registered_block_types = array();
+
+	/**
+	 * Container for the main instance of the class.
+	 *
+	 * @since 5.0.0
+	 * @var WP_Block_Type_Registry|null
+	 */
+	private static $instance = null;
+
+	/**
+	 * Registers a block type.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param string|WP_Block_Type $name Block type name including namespace, or alternatively a
+	 *                                   complete WP_Block_Type instance. In case a WP_Block_Type
+	 *                                   is provided, the $args parameter will be ignored.
+	 * @param array                $args {
+	 *     Optional. Array of block type arguments. Any arguments may be defined, however the
+	 *     ones described below are supported by default. Default empty array.
+	 *
+	 *     @type callable $render_callback Callback used to render blocks of this block type.
+	 *     @type array    $attributes      Block attributes mapping, property name to schema.
+	 * }
+	 * @return WP_Block_Type|false The registered block type on success, or false on failure.
+	 */
+	public function register( $name, $args = array() ) {
+		$block_type = null;
+		if ( $name instanceof WP_Block_Type ) {
+			$block_type = $name;
+			$name       = $block_type->name;
+		}
+
+		if ( ! is_string( $name ) ) {
+			$message = __( 'Block type names must be strings.' );
+			_doing_it_wrong( __METHOD__, $message, '5.0.0' );
+			return false;
+		}
+
+		if ( preg_match( '/[A-Z]+/', $name ) ) {
+			$message = __( 'Block type names must not contain uppercase characters.' );
+			_doing_it_wrong( __METHOD__, $message, '5.0.0' );
+			return false;
+		}
+
+		$name_matcher = '/^[a-z0-9-]+\/[a-z0-9-]+$/';
+		if ( ! preg_match( $name_matcher, $name ) ) {
+			$message = __( 'Block type names must contain a namespace prefix. Example: my-plugin/my-custom-block-type' );
+			_doing_it_wrong( __METHOD__, $message, '5.0.0' );
+			return false;
+		}
+
+		if ( $this->is_registered( $name ) ) {
+			/* translators: %s: block name */
+			$message = sprintf( __( 'Block type "%s" is already registered.' ), $name );
+			_doing_it_wrong( __METHOD__, $message, '5.0.0' );
+			return false;
+		}
+
+		if ( ! $block_type ) {
+			$block_type = new WP_Block_Type( $name, $args );
+		}
+
+		$this->registered_block_types[ $name ] = $block_type;
+
+		return $block_type;
+	}
+
+	/**
+	 * Unregisters a block type.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param string|WP_Block_Type $name Block type name including namespace, or alternatively a
+	 *                                   complete WP_Block_Type instance.
+	 * @return WP_Block_Type|false The unregistered block type on success, or false on failure.
+	 */
+	public function unregister( $name ) {
+		if ( $name instanceof WP_Block_Type ) {
+			$name = $name->name;
+		}
+
+		if ( ! $this->is_registered( $name ) ) {
+			/* translators: %s: block name */
+			$message = sprintf( __( 'Block type "%s" is not registered.' ), $name );
+			_doing_it_wrong( __METHOD__, $message, '5.0.0' );
+			return false;
+		}
+
+		$unregistered_block_type = $this->registered_block_types[ $name ];
+		unset( $this->registered_block_types[ $name ] );
+
+		return $unregistered_block_type;
+	}
+
+	/**
+	 * Retrieves a registered block type.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param string $name Block type name including namespace.
+	 * @return WP_Block_Type|null The registered block type, or null if it is not registered.
+	 */
+	public function get_registered( $name ) {
+		if ( ! $this->is_registered( $name ) ) {
+			return null;
+		}
+
+		return $this->registered_block_types[ $name ];
+	}
+
+	/**
+	 * Retrieves all registered block types.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @return WP_Block_Type[] Associative array of `$block_type_name => $block_type` pairs.
+	 */
+	public function get_all_registered() {
+		return $this->registered_block_types;
+	}
+
+	/**
+	 * Checks if a block type is registered.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param string $name Block type name including namespace.
+	 * @return bool True if the block type is registered, false otherwise.
+	 */
+	public function is_registered( $name ) {
+		return isset( $this->registered_block_types[ $name ] );
+	}
+
+	/**
+	 * Utility method to retrieve the main instance of the class.
+	 *
+	 * The instance will be created if it does not exist yet.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @return WP_Block_Type_Registry The main instance.
+	 */
+	public static function get_instance() {
+		if ( null === self::$instance ) {
+			self::$instance = new self();
+		}
+
+		return self::$instance;
+	}
+}