Content Guidelines: Add experimental REST API and custom post type

lib/experimental/content-guidelines/class-gutenberg-content-guidelines-post-type.php

@@ -0,0 +1,260 @@
+<?php
+/**
+ * Content Guidelines Post Type registration.
+ *
+ * @package gutenberg
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Handles registration of the Content Guidelines custom post type.
+ */
+class Gutenberg_Content_Guidelines_Post_Type {
+
+	/**
+	 * The post type name.
+	 *
+	 * @var string
+	 */
+	const POST_TYPE = 'wp_content_guideline';
+
+	/**
+	 * The standard guideline category meta keys.
+	 *
+	 * @var array
+	 */
+	const CATEGORY_META_KEYS = array(
+		'copy',
+		'images',
+		'site',
+		'additional',
+	);
+
+	/**
+	 * All valid guideline category keys for filtering.
+	 *
+	 * Includes standard categories plus 'blocks'.
+	 *
+	 * @var array
+	 */
+	const VALID_CATEGORIES = array(
+		'copy',
+		'images',
+		'site',
+		'additional',
+		'blocks',
+	);
+
+	/**
+	 * Valid guideline statuses.
+	 *
+	 * @var array
+	 */
+	const VALID_STATUSES = array(
+		'draft',
+		'publish',
+	);
+
+	/**
+	 * Prefix for block-specific guideline meta keys.
+	 *
+	 * @var string
+	 */
+	const BLOCK_META_PREFIX = '_content_guideline_block_';
+
+	/**
+	 * Register the custom post type.
+	 */
+	public static function register() {
+		$args = array(
+			'labels'                          => array(
+				'name'          => __( 'Content Guidelines', 'gutenberg' ),
+				'singular_name' => __( 'Content Guidelines', 'gutenberg' ),
+			),
+			'public'                          => false,
+			'publicly_queryable'              => false,
+			'show_ui'                         => false,
+			'show_in_menu'                    => false,
+			'show_in_rest'                    => true,
+			'rest_base'                       => 'content-guidelines',
+			'rest_controller_class'           => 'Gutenberg_Content_Guidelines_REST_Controller',
+			'revisions_rest_controller_class' => 'Gutenberg_Content_Guidelines_Revisions_Controller',
+			'capability_type'                 => 'post',
+			'capabilities'                    => array(
+				'read'                   => 'edit_posts',
+				'create_posts'           => 'manage_options',
+				'edit_posts'             => 'manage_options',
+				'edit_published_posts'   => 'manage_options',
+				'delete_posts'           => 'manage_options',
+				'delete_published_posts' => 'manage_options',
+				'edit_others_posts'      => 'manage_options',
+				'delete_others_posts'    => 'manage_options',
+				'publish_posts'          => 'manage_options',
+			),
+			'map_meta_cap'                    => true,
+			'supports'                        => array( 'revisions' ),
+			'hierarchical'                    => false,
+			'has_archive'                     => false,
+			'rewrite'                         => false,
+			'query_var'                       => false,
+			'can_export'                      => true,
+		);
+
+		register_post_type( self::POST_TYPE, $args );
+	}
+
+	/**
+	 * Register post meta fields with revision support.
+	 */
+	public static function register_post_meta() {
+		$meta_args = array(
+			'show_in_rest'      => true,
+			'single'            => true,
+			'type'              => 'string',
+			'revisions_enabled' => true,
+			'auth_callback'     => function () {
+				return current_user_can( 'manage_options' );
+			},
+			'sanitize_callback' => 'sanitize_textarea_field',
+		);
+
+		// Register standard category meta.
+		foreach ( self::CATEGORY_META_KEYS as $category ) {
+			register_post_meta( self::POST_TYPE, '_content_guideline_' . $category, $meta_args );
+		}
+
+		// Register meta for content blocks.
+		foreach ( self::get_content_blocks() as $block_name ) {
+			register_post_meta( self::POST_TYPE, self::block_name_to_meta_key( $block_name ), $meta_args );
+		}
+	}
+
+	/**
+	 * Get block names that have content role attributes.
+	 *
+	 * @return array Block names with content role.
+	 */
+	public static function get_content_blocks() {
+		$content_blocks = array();
+		$registry       = WP_Block_Type_Registry::get_instance();
+
+		foreach ( $registry->get_all_registered() as $block_type ) {
+			if ( self::block_has_content_role( $block_type ) ) {
+				$content_blocks[] = $block_type->name;
+			}
+		}
+
+		return $content_blocks;
+	}
+
+	/**
+	 * Check if a block type has any attribute with content role.
+	 *
+	 * @param WP_Block_Type $block_type The block type to check.
+	 * @return bool True if block has content role attribute.
+	 */
+	private static function block_has_content_role( $block_type ) {
+		if ( empty( $block_type->attributes ) ) {
+			return false;
+		}
+
+		foreach ( $block_type->attributes as $attribute ) {
+			if ( isset( $attribute['role'] ) && 'content' === $attribute['role'] ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Convert a block name to a meta key.
+	 *
+	 * @param string $block_name The block name (e.g., 'core/paragraph').
+	 * @return string The meta key (e.g., '_content_guideline_block_core_paragraph').
+	 */
+	public static function block_name_to_meta_key( $block_name ) {
+		// Replace '/' with '_' to create a valid meta key.
+		$sanitized = str_replace( '/', '_', $block_name );
+		return self::BLOCK_META_PREFIX . $sanitized;
+	}
+
+	/**
+	 * Convert a meta key back to a block name.
+	 *
+	 * @param string $meta_key The meta key (e.g., '_content_guideline_block_core_paragraph').
+	 * @return string The block name (e.g., 'core/paragraph').
+	 */
+	public static function meta_key_to_block_name( $meta_key ) {
+		// Remove prefix and convert first '_' back to '/'.
+		$without_prefix = str_replace( self::BLOCK_META_PREFIX, '', $meta_key );
+		// Replace first underscore with '/' (namespace separator).
+		return preg_replace( '/_/', '/', $without_prefix, 1 );
+	}
+
+	/**
+	 * Check if a meta key is a block guideline meta key.
+	 *
+	 * @param string $meta_key The meta key to check.
+	 * @return bool True if it's a block guideline meta key.
+	 */
+	public static function is_block_meta_key( $meta_key ) {
+		return strpos( $meta_key, self::BLOCK_META_PREFIX ) === 0;
+	}
+
+	/**
+	 * Gets guideline categories from post meta.
+	 *
+	 * Shared between the post controller and revisions controller.
+	 *
+	 * @param int $post_id Post ID (can be a post or revision ID).
+	 * @return array Guideline categories.
+	 */
+	public static function get_guideline_categories_from_meta( $post_id ) {
+		$category_labels = array(
+			'copy'       => __( 'Copy Guidelines', 'gutenberg' ),
+			'images'     => __( 'Image Guidelines', 'gutenberg' ),
+			'site'       => __( 'Site Context', 'gutenberg' ),
+			'additional' => __( 'Additional Guidelines', 'gutenberg' ),
+		);
+
+		$guideline_categories = array();
+
+		// Get standard categories.
+		foreach ( self::CATEGORY_META_KEYS as $category ) {
+			$meta_key = '_content_guideline_' . $category;
+			$value    = get_post_meta( $post_id, $meta_key, true );
+
+			$guideline_categories[ $category ] = array(
+				'label'      => $category_labels[ $category ],
+				'guidelines' => $value,
+			);
+		}
+
+		// Get block-specific guidelines from individual meta keys.
+		$all_meta = get_post_meta( $post_id );
+
+		$blocks = array();
+		foreach ( $all_meta as $meta_key => $meta_values ) {
+			if ( self::is_block_meta_key( $meta_key ) ) {
+				$block_name = self::meta_key_to_block_name( $meta_key );
+				$value      = isset( $meta_values[0] ) ? $meta_values[0] : '';
+
+				if ( ! empty( $value ) ) {
+					$blocks[ $block_name ] = array(
+						'guidelines' => $value,
+					);
+				}
+			}
+		}
+
+		if ( ! empty( $blocks ) ) {
+			$guideline_categories['blocks'] = $blocks;
+		}
+
+		return $guideline_categories;
+	}
+}