Blocks: Introduce WP_Block_Type and WP_Block_Type_Registry classes.

These are the foundational classes allowing blocks to be registered and used throughout WordPress.

This commit also includes the `has_block()` and `has_blocks()` functions, which are required for unit testing these classes.

Merges [43742] from the 5.0 branch to trunk.

Props adamsilverstein, danielbachhuber, desrosj.
Fixes #45097.
See #45109.

Built from https://develop.svn.wordpress.org/trunk@44108


git-svn-id: http://core.svn.wordpress.org/trunk@43938 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/blocks.php

@@ -0,0 +1,61 @@
+<?php
+/**
+ * Functions related to registering and parsing blocks.
+ *
+ * @package WordPress
+ * @subpackage Blocks
+ * @since 5.0.0
+ */
+
+/**
+ * Determine whether a post or content string has blocks.
+ *
+ * This test optimizes for performance rather than strict accuracy, detecting
+ * the pattern of a block but not validating its structure. For strict accuracy,
+ * you should use the block parser on post content.
+ *
+ * @since 5.0.0
+ * @see parse_blocks()
+ *
+ * @param int|string|WP_Post|null $post Optional. Post content, post ID, or post object. Defaults to global $post.
+ * @return bool Whether the post has blocks.
+ */
+function has_blocks( $post = null ) {
+	if ( ! is_string( $post ) ) {
+		$wp_post = get_post( $post );
+		if ( $wp_post instanceof WP_Post ) {
+			$post = $wp_post->post_content;
+		}
+	}
+
+	return false !== strpos( (string) $post, '<!-- wp:' );
+}
+
+/**
+ * Determine whether a $post or a string contains a specific block type.
+ *
+ * This test optimizes for performance rather than strict accuracy, detecting
+ * the block type exists but not validating its structure. For strict accuracy,
+ * you should use the block parser on post content.
+ *
+ * @since 5.0.0
+ * @see parse_blocks()
+ *
+ * @param string                  $block_type Full Block type to look for.
+ * @param int|string|WP_Post|null $post Optional. Post content, post ID, or post object. Defaults to global $post.
+ * @return bool Whether the post content contains the specified block.
+ */
+function has_block( $block_type, $post = null ) {
+	if ( ! has_blocks( $post ) ) {
+		return false;
+	}
+
+	if ( ! is_string( $post ) ) {
+		$wp_post = get_post( $post );
+		if ( $wp_post instanceof WP_Post ) {
+			$post = $wp_post->post_content;
+		}
+	}
+
+	return false !== strpos( $post, '<!-- wp:' . $block_type . ' ' );
+}

wp-includes/class-wp-block-type-registry.php

@@ -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;
+	}
+}