1<?php
2/**
3 * Block Metadata Registry
4 *
5 * @package WordPress
6 * @subpackage Blocks
7 * @since 6.7.0
8 */
9
10/**
11 * Class used for managing block metadata collections.
12 *
13 * The WP_Block_Metadata_Registry allows plugins to register metadata for large
14 * collections of blocks (e.g., 50-100+) using a single PHP file. This approach
15 * reduces the need to read and decode multiple `block.json` files, enhancing
16 * performance through opcode caching.
17 *
18 * @since 6.7.0
19 */
20class WP_Block_Metadata_Registry {
21
22 /**
23 * Container for storing block metadata collections.
24 *
25 * Each entry maps a base path to its corresponding metadata and callback.
26 *
27 * @since 6.7.0
28 * @var array<string, array<string, mixed>>
29 */
30 private static $collections = array();
31
32 /**
33 * Caches the last matched collection path for performance optimization.
34 *
35 * @since 6.7.0
36 * @var string|null
37 */
38 private static $last_matched_collection = null;
39
40 /**
41 * Stores the default allowed collection root paths.
42 *
43 * @since 6.7.2
44 * @var string[]|null
45 */
46 private static $default_collection_roots = null;
47
48 /**
49 * Registers a block metadata collection.
50 *
51 * This method allows registering a collection of block metadata from a single
52 * manifest file, improving performance for large sets of blocks.
53 *
54 * The manifest file should be a PHP file that returns an associative array, where
55 * the keys are the block identifiers (without their namespace) and the values are
56 * the corresponding block metadata arrays. The block identifiers must match the
57 * parent directory name for the respective `block.json` file.
58 *
59 * Example manifest file structure:
60 * ```
61 * return array(
62 * 'example-block' => array(
63 * 'title' => 'Example Block',
64 * 'category' => 'widgets',
65 * 'icon' => 'smiley',
66 * // ... other block metadata
67 * ),
68 * 'another-block' => array(
69 * 'title' => 'Another Block',
70 * 'category' => 'formatting',
71 * 'icon' => 'star-filled',
72 * // ... other block metadata
73 * ),
74 * // ... more block metadata entries
75 * );
76 * ```
77 *
78 * @since 6.7.0
79 *
80 * @param string $path The absolute base path for the collection ( e.g., WP_PLUGIN_DIR . '/my-plugin/blocks/' ).
81 * @param string $manifest The absolute path to the manifest file containing the metadata collection.
82 * @return bool True if the collection was registered successfully, false otherwise.
83 */
84 public static function register_collection( $path, $manifest ) {
85 $path = rtrim( wp_normalize_path( $path ), '/' );
86
87 $collection_roots = self::get_default_collection_roots();
88
89 /**
90 * Filters the root directory paths for block metadata collections.
91 *
92 * Any block metadata collection that is registered must not use any of these paths, or any parent directory
93 * path of them. Most commonly, block metadata collections should reside within one of these paths, though in
94 * some scenarios they may also reside in entirely different directories (e.g. in case of symlinked plugins).
95 *
96 * Example:
97 * * It is allowed to register a collection with path `WP_PLUGIN_DIR . '/my-plugin'`.
98 * * It is not allowed to register a collection with path `WP_PLUGIN_DIR`.
99 * * It is not allowed to register a collection with path `dirname( WP_PLUGIN_DIR )`.
100 *
101 * The default list encompasses the `wp-includes` directory, as well as the root directories for plugins,
102 * must-use plugins, and themes. This filter can be used to expand the list, e.g. to custom directories that
103 * contain symlinked plugins, so that these root directories cannot be used themselves for a block metadata
104 * collection either.
105 *
106 * @since 6.7.2
107 *
108 * @param string[] $collection_roots List of allowed metadata collection root paths.
109 */
110 $collection_roots = apply_filters( 'wp_allowed_block_metadata_collection_roots', $collection_roots );
111
112 $collection_roots = array_unique(
113 array_map(
114 static function ( $allowed_root ) {
115 return rtrim( wp_normalize_path( $allowed_root ), '/' );
116 },
117 $collection_roots
118 )
119 );
120
121 // Check if the path is valid:
122 if ( ! self::is_valid_collection_path( $path, $collection_roots ) ) {
123 _doing_it_wrong(
124 __METHOD__,
125 sprintf(
126 /* translators: %s: list of allowed collection roots */
127 __( 'Block metadata collections cannot be registered as one of the following directories or their parent directories: %s' ),
128 esc_html( implode( wp_get_list_item_separator(), $collection_roots ) )
129 ),
130 '6.7.2'
131 );
132 return false;
133 }
134
135 if ( ! file_exists( $manifest ) ) {
136 _doing_it_wrong(
137 __METHOD__,
138 __( 'The specified manifest file does not exist.' ),
139 '6.7.0'
140 );
141 return false;
142 }
143
144 self::$collections[ $path ] = array(
145 'manifest' => $manifest,
146 'metadata' => null,
147 );
148
149 return true;
150 }
151
152 /**
153 * Retrieves block metadata for a given block within a specific collection.
154 *
155 * This method uses the registered collections to efficiently lookup
156 * block metadata without reading individual `block.json` files.
157 *
158 * @since 6.7.0
159 *
160 * @param string $file_or_folder The path to the file or folder containing the block.
161 * @return array|null The block metadata for the block, or null if not found.
162 */
163 public static function get_metadata( $file_or_folder ) {
164 $file_or_folder = wp_normalize_path( $file_or_folder );
165
166 $path = self::find_collection_path( $file_or_folder );
167 if ( ! $path ) {
168 return null;
169 }
170
171 $collection = &self::$collections[ $path ];
172
173 if ( null === $collection['metadata'] ) {
174 // Load the manifest file if not already loaded
175 $collection['metadata'] = require $collection['manifest'];
176 }
177
178 // Get the block name from the path.
179 $block_name = self::default_identifier_callback( $file_or_folder );
180
181 return isset( $collection['metadata'][ $block_name ] ) ? $collection['metadata'][ $block_name ] : null;
182 }
183
184 /**
185 * Gets the list of absolute paths to all block metadata files that are part of the given collection.
186 *
187 * For instance, if a block metadata collection is registered with path `WP_PLUGIN_DIR . '/my-plugin/blocks/'`,
188 * and the manifest file includes metadata for two blocks `'block-a'` and `'block-b'`, the result of this method
189 * will be an array containing:
190 * * `WP_PLUGIN_DIR . '/my-plugin/blocks/block-a/block.json'`
191 * * `WP_PLUGIN_DIR . '/my-plugin/blocks/block-b/block.json'`
192 *
193 * @since 6.8.0
194 *
195 * @param string $path The absolute base path for a previously registered collection.
196 * @return string[] List of block metadata file paths, or an empty array if the given `$path` is invalid.
197 */
198 public static function get_collection_block_metadata_files( $path ) {
199 $path = rtrim( wp_normalize_path( $path ), '/' );
200
201 if ( ! isset( self::$collections[ $path ] ) ) {
202 _doing_it_wrong(
203 __METHOD__,
204 __( 'No registered block metadata collection was found for the provided path.' ),
205 '6.8.0'
206 );
207 return array();
208 }
209
210 $collection = &self::$collections[ $path ];
211
212 if ( null === $collection['metadata'] ) {
213 // Load the manifest file if not already loaded.
214 $collection['metadata'] = require $collection['manifest'];
215 }
216
217 return array_map(
218 // No normalization necessary since `$path` is already normalized and `$block_name` is just a folder name.
219 static function ( $block_name ) use ( $path ) {
220 return "{$path}/{$block_name}/block.json";
221 },
222 array_keys( $collection['metadata'] )
223 );
224 }
225
226 /**
227 * Finds the collection path for a given file or folder.
228 *
229 * @since 6.7.0
230 *
231 * @param string $file_or_folder The normalized path to the file or folder.
232 * @return string|null The normalized collection path if found, or null if not found.
233 */
234 private static function find_collection_path( $file_or_folder ) {
235 if ( empty( $file_or_folder ) ) {
236 return null;
237 }
238
239 // Check the last matched collection first, since block registration usually happens in batches per plugin or theme.
240 $path = rtrim( $file_or_folder, '/' );
241 if ( self::$last_matched_collection && str_starts_with( $path, self::$last_matched_collection ) ) {
242 return self::$last_matched_collection;
243 }
244
245 $collection_paths = array_keys( self::$collections );
246 foreach ( $collection_paths as $collection_path ) {
247 if ( str_starts_with( $path, $collection_path ) ) {
248 self::$last_matched_collection = $collection_path;
249 return $collection_path;
250 }
251 }
252 return null;
253 }
254
255 /**
256 * Checks if metadata exists for a given block name in a specific collection.
257 *
258 * @since 6.7.0
259 *
260 * @param string $file_or_folder The path to the file or folder containing the block metadata.
261 * @return bool True if metadata exists for the block, false otherwise.
262 */
263 public static function has_metadata( $file_or_folder ) {
264 return null !== self::get_metadata( $file_or_folder );
265 }
266
267 /**
268 * Default identifier function to determine the block identifier from a given path.
269 *
270 * This function extracts the block identifier from the path:
271 * - For 'block.json' files, it uses the parent directory name.
272 * - For directories, it uses the directory name itself.
273 * - For empty paths, it returns an empty string.
274 *
275 * For example:
276 * - Path: '/wp-content/plugins/my-plugin/blocks/example/block.json'
277 * Identifier: 'example'
278 * - Path: '/wp-content/plugins/my-plugin/blocks/another-block'
279 * Identifier: 'another-block'
280 *
281 * This default behavior matches the standard WordPress block structure.
282 *
283 * @since 6.7.0
284 *
285 * @param string $path The normalized file or folder path to determine the block identifier from.
286 * @return string The block identifier, or an empty string if the path is empty.
287 */
288 private static function default_identifier_callback( $path ) {
289 // Ensure $path is not empty to prevent unexpected behavior.
290 if ( empty( $path ) ) {
291 return '';
292 }
293
294 if ( str_ends_with( $path, 'block.json' ) ) {
295 // Return the parent directory name if it's a block.json file.
296 return basename( dirname( $path ) );
297 }
298
299 // Otherwise, assume it's a directory and return its name.
300 return basename( $path );
301 }
302
303 /**
304 * Checks whether the given block metadata collection path is valid against the list of collection roots.
305 *
306 * @since 6.7.2
307 *
308 * @param string $path Normalized block metadata collection path, without trailing slash.
309 * @param string[] $collection_roots List of normalized collection root paths, without trailing slashes.
310 * @return bool True if the path is allowed, false otherwise.
311 */
312 private static function is_valid_collection_path( $path, $collection_roots ) {
313 foreach ( $collection_roots as $allowed_root ) {
314 // If the path matches any root exactly, it is invalid.
315 if ( $allowed_root === $path ) {
316 return false;
317 }
318
319 // If the path is a parent path of any of the roots, it is invalid.
320 if ( str_starts_with( $allowed_root, $path ) ) {
321 return false;
322 }
323 }
324
325 return true;
326 }
327
328 /**
329 * Gets the default collection root directory paths.
330 *
331 * @since 6.7.2
332 *
333 * @return string[] List of directory paths within which metadata collections are allowed.
334 */
335 private static function get_default_collection_roots() {
336 if ( isset( self::$default_collection_roots ) ) {
337 return self::$default_collection_roots;
338 }
339
340 $collection_roots = array(
341 wp_normalize_path( ABSPATH . WPINC ),
342 wp_normalize_path( WP_CONTENT_DIR ),
343 wp_normalize_path( WPMU_PLUGIN_DIR ),
344 wp_normalize_path( WP_PLUGIN_DIR ),
345 );
346
347 $theme_roots = get_theme_roots();
348 if ( ! is_array( $theme_roots ) ) {
349 $theme_roots = array( $theme_roots );
350 }
351 foreach ( $theme_roots as $theme_root ) {
352 $collection_roots[] = trailingslashit( wp_normalize_path( WP_CONTENT_DIR ) ) . ltrim( wp_normalize_path( $theme_root ), '/' );
353 }
354
355 self::$default_collection_roots = array_unique( $collection_roots );
356 return self::$default_collection_roots;
357 }
358}
359