<?php
/**
* Block Metadata Registry
*
* @package WordPress
* @subpackage Blocks
* @since 6.7.0
*/
/**
* Class used for managing block metadata collections.
*
* The WP_Block_Metadata_Registry allows plugins to register metadata for large
* collections of blocks (e.g., 50-100+) using a single PHP file. This approach
* reduces the need to read and decode multiple `block.json` files, enhancing
* performance through opcode caching.
*
* @since 6.7.0
*/
class WP_Block_Metadata_Registry {
/**
* Container for storing block metadata collections.
*
* Each entry maps a base path to its corresponding metadata and callback.
*
* @since 6.7.0
* @var array<string, array<string, mixed>>
*/
private static $collections = array();
/**
* Caches the last matched collection path for performance optimization.
*
* @since 6.7.0
* @var string|null
*/
private static $last_matched_collection = null;
/**
* Stores the default allowed collection root paths.
*
* @since 6.7.2
* @var string[]|null
*/
private static $default_collection_roots = null;
/**
* Registers a block metadata collection.
*
* This method allows registering a collection of block metadata from a single
* manifest file, improving performance for large sets of blocks.
*
* The manifest file should be a PHP file that returns an associative array, where
* the keys are the block identifiers (without their namespace) and the values are
* the corresponding block metadata arrays. The block identifiers must match the
* parent directory name for the respective `block.json` file.
*
* Example manifest file structure:
* ```
* return array(
* 'example-block' => array(
* 'title' => 'Example Block',
* 'category' => 'widgets',
* 'icon' => 'smiley',
* // ... other block metadata
* ),
* 'another-block' => array(
* 'title' => 'Another Block',
* 'category' => 'formatting',
* 'icon' => 'star-filled',
* // ... other block metadata
* ),
* // ... more block metadata entries
* );
* ```
*
* @since 6.7.0
*
* @param string $path The absolute base path for the collection ( e.g., WP_PLUGIN_DIR . '/my-plugin/blocks/' ).
* @param string $manifest The absolute path to the manifest file containing the metadata collection.
* @return bool True if the collection was registered successfully, false otherwise.
*/
public static function register_collection( $path, $manifest ) {
$path = rtrim( wp_normalize_path( $path ), '/' );
$collection_roots = self::get_default_collection_roots();
/**
* Filters the root directory paths for block metadata collections.
*
* Any block metadata collection that is registered must not use any of these paths, or any parent directory
* path of them. Most commonly, block metadata collections should reside within one of these paths, though in
* some scenarios they may also reside in entirely different directories (e.g. in case of symlinked plugins).
*
* Example:
* * It is allowed to register a collection with path `WP_PLUGIN_DIR . '/my-plugin'`.
* * It is not allowed to register a collection with path `WP_PLUGIN_DIR`.
* * It is not allowed to register a collection with path `dirname( WP_PLUGIN_DIR )`.
*
* The default list encompasses the `wp-includes` directory, as well as the root directories for plugins,
* must-use plugins, and themes. This filter can be used to expand the list, e.g. to custom directories that
* contain symlinked plugins, so that these root directories cannot be used themselves for a block metadata
* collection either.
*
* @since 6.7.2
*
* @param string[] $collection_roots List of allowed metadata collection root paths.
*/
$collection_roots = apply_filters( 'wp_allowed_block_metadata_collection_roots', $collection_roots );
$collection_roots = array_unique(
array_map(
static function ( $allowed_root ) {
return rtrim( wp_normalize_path( $allowed_root ), '/' );
},
$collection_roots
)
);
// Check if the path is valid:
if ( ! self::is_valid_collection_path( $path, $collection_roots ) ) {
_doing_it_wrong(
__METHOD__,
sprintf(
/* translators: %s: list of allowed collection roots */
__( 'Block metadata collections cannot be registered as one of the following directories or their parent directories: %s' ),
esc_html( implode( wp_get_list_item_separator(), $collection_roots ) )
),
'6.7.2'
);
return false;
}
if ( ! file_exists( $manifest ) ) {
_doing_it_wrong(
__METHOD__,
__( 'The specified manifest file does not exist.' ),
'6.7.0'
);
return false;
}
self::$collections[ $path ] = array(
'manifest' => $manifest,
'metadata' => null,
);
return true;
}
/**
* Retrieves block metadata for a given block within a specific collection.
*
* This method uses the registered collections to efficiently lookup
* block metadata without reading individual `block.json` files.
*
* @since 6.7.0
*
* @param string $file_or_folder The path to the file or folder containing the block.
* @return array|null The block metadata for the block, or null if not found.
*/
public static function get_metadata( $file_or_folder ) {
$file_or_folder = wp_normalize_path( $file_or_folder );
$path = self::find_collection_path( $file_or_folder );
if ( ! $path ) {
return null;
}
$collection = &self::$collections[ $path ];
if ( null === $collection['metadata'] ) {
// Load the manifest file if not already loaded
$collection['metadata'] = require $collection['manifest'];
}
// Get the block name from the path.
$block_name = self::default_identifier_callback( $file_or_folder );
return isset( $collection['metadata'][ $block_name ] ) ? $collection['metadata'][ $block_name ] : null;
}
/**
* Gets the list of absolute paths to all block metadata files that are part of the given collection.
*
* For instance, if a block metadata collection is registered with path `WP_PLUGIN_DIR . '/my-plugin/blocks/'`,
* and the manifest file includes metadata for two blocks `'block-a'` and `'block-b'`, the result of this method
* will be an array containing:
* * `WP_PLUGIN_DIR . '/my-plugin/blocks/block-a/block.json'`
* * `WP_PLUGIN_DIR . '/my-plugin/blocks/block-b/block.json'`
*
* @since 6.8.0
*
* @param string $path The absolute base path for a previously registered collection.
* @return string[] List of block metadata file paths, or an empty array if the given `$path` is invalid.
*/
public static function get_collection_block_metadata_files( $path ) {
$path = rtrim( wp_normalize_path( $path ), '/' );
if ( ! isset( self::$collections[ $path ] ) ) {
_doing_it_wrong(
__METHOD__,
__( 'No registered block metadata collection was found for the provided path.' ),
'6.8.0'
);
return array();
}
$collection = &self::$collections[ $path ];
if ( null === $collection['metadata'] ) {
// Load the manifest file if not already loaded.
$collection['metadata'] = require $collection['manifest'];
}
return array_map(
// No normalization necessary since `$path` is already normalized and `$block_name` is just a folder name.
static function ( $block_name ) use ( $path ) {
return "{$path}/{$block_name}/block.json";
},
array_keys( $collection['metadata'] )
);
}
/**
* Finds the collection path for a given file or folder.
*
* @since 6.7.0
*
* @param string $file_or_folder The normalized path to the file or folder.
* @return string|null The normalized collection path if found, or null if not found.
*/
private static function find_collection_path( $file_or_folder ) {
if ( empty( $file_or_folder ) ) {
return null;
}
// Check the last matched collection first, since block registration usually happens in batches per plugin or theme.
$path = rtrim( $file_or_folder, '/' );
if ( self::$last_matched_collection && str_starts_with( $path, self::$last_matched_collection ) ) {
return self::$last_matched_collection;
}
$collection_paths = array_keys( self::$collections );
foreach ( $collection_paths as $collection_path ) {
if ( str_starts_with( $path, $collection_path ) ) {
self::$last_matched_collection = $collection_path;
return $collection_path;
}
}
return null;
}
/**
* Checks if metadata exists for a given block name in a specific collection.
*
* @since 6.7.0
*
* @param string $file_or_folder The path to the file or folder containing the block metadata.
* @return bool True if metadata exists for the block, false otherwise.
*/
public static function has_metadata( $file_or_folder ) {
return null !== self::get_metadata( $file_or_folder );
}
/**
* Default identifier function to determine the block identifier from a given path.
*
* This function extracts the block identifier from the path:
* - For 'block.json' files, it uses the parent directory name.
* - For directories, it uses the directory name itself.
* - For empty paths, it returns an empty string.
*
* For example:
* - Path: '/wp-content/plugins/my-plugin/blocks/example/block.json'
* Identifier: 'example'
* - Path: '/wp-content/plugins/my-plugin/blocks/another-block'
* Identifier: 'another-block'
*
* This default behavior matches the standard WordPress block structure.
*
* @since 6.7.0
*
* @param string $path The normalized file or folder path to determine the block identifier from.
* @return string The block identifier, or an empty string if the path is empty.
*/
private static function default_identifier_callback( $path ) {
// Ensure $path is not empty to prevent unexpected behavior.
if ( empty( $path ) ) {
return '';
}
if ( str_ends_with( $path, 'block.json' ) ) {
// Return the parent directory name if it's a block.json file.
return basename( dirname( $path ) );
}
// Otherwise, assume it's a directory and return its name.
return basename( $path );
}
/**
* Checks whether the given block metadata collection path is valid against the list of collection roots.
*
* @since 6.7.2
*
* @param string $path Normalized block metadata collection path, without trailing slash.
* @param string[] $collection_roots List of normalized collection root paths, without trailing slashes.
* @return bool True if the path is allowed, false otherwise.
*/
private static function is_valid_collection_path( $path, $collection_roots ) {
foreach ( $collection_roots as $allowed_root ) {
// If the path matches any root exactly, it is invalid.
if ( $allowed_root === $path ) {
return false;
}
// If the path is a parent path of any of the roots, it is invalid.
if ( str_starts_with( $allowed_root, $path ) ) {
return false;
}
}
return true;
}
/**
* Gets the default collection root directory paths.
*
* @since 6.7.2
*
* @return string[] List of directory paths within which metadata collections are allowed.
*/
private static function get_default_collection_roots() {
if ( isset( self::$default_collection_roots ) ) {
return self::$default_collection_roots;
}
$collection_roots = array(
wp_normalize_path( ABSPATH . WPINC ),
wp_normalize_path( WP_CONTENT_DIR ),
wp_normalize_path( WPMU_PLUGIN_DIR ),
wp_normalize_path( WP_PLUGIN_DIR ),
);
$theme_roots = get_theme_roots();
if ( ! is_array( $theme_roots ) ) {
$theme_roots = array( $theme_roots );
}
foreach ( $theme_roots as $theme_root ) {
$collection_roots[] = trailingslashit( wp_normalize_path( WP_CONTENT_DIR ) ) . ltrim( wp_normalize_path( $theme_root ), '/' );
}
self::$default_collection_roots = array_unique( $collection_roots );
return self::$default_collection_roots;
}
}