<?php
/**
* Script Modules API: WP_Script_Modules class.
*
* Native support for ES Modules and Import Maps.
*
* @package WordPress
* @subpackage Script Modules
*/
/**
* Core class used to register script modules.
*
* @since 6.5.0
*/
class WP_Script_Modules {
/**
* Holds the registered script modules, keyed by script module identifier.
*
* @since 6.5.0
* @var array[]
*/
private $registered = array();
/**
* Holds the script module identifiers that were enqueued before registered.
*
* @since 6.5.0
* @var array<string, true>
*/
private $enqueued_before_registered = array();
/**
* Registers the script module if no script module with that script module
* identifier has already been registered.
*
* @since 6.5.0
*
* @param string $id The identifier of the script module. Should be unique. It will be used in the
* final import map.
* @param string $src Optional. Full URL of the script module, or path of the script module relative
* to the WordPress root directory. If it is provided and the script module has
* not been registered yet, it will be registered.
* @param array $deps {
* Optional. List of dependencies.
*
* @type string|array ...$0 {
* An array of script module identifiers of the dependencies of this script
* module. The dependencies can be strings or arrays. If they are arrays,
* they need an `id` key with the script module identifier, and can contain
* an `import` key with either `static` or `dynamic`. By default,
* dependencies that don't contain an `import` key are considered static.
*
* @type string $id The script module identifier.
* @type string $import Optional. Import type. May be either `static` or
* `dynamic`. Defaults to `static`.
* }
* }
* @param string|false|null $version Optional. String specifying the script module version number. Defaults to false.
* It is added to the URL as a query string for cache busting purposes. If $version
* is set to false, the version number is the currently installed WordPress version.
* If $version is set to null, no version is added.
*/
public function register( string $id, string $src, array $deps = array(), $version = false ) {
if ( ! isset( $this->registered[ $id ] ) ) {
$dependencies = array();
foreach ( $deps as $dependency ) {
if ( is_array( $dependency ) ) {
if ( ! isset( $dependency['id'] ) ) {
_doing_it_wrong( __METHOD__, __( 'Missing required id key in entry among dependencies array.' ), '6.5.0' );
continue;
}
$dependencies[] = array(
'id' => $dependency['id'],
'import' => isset( $dependency['import'] ) && 'dynamic' === $dependency['import'] ? 'dynamic' : 'static',
);
} elseif ( is_string( $dependency ) ) {
$dependencies[] = array(
'id' => $dependency,
'import' => 'static',
);
} else {
_doing_it_wrong( __METHOD__, __( 'Entries in dependencies array must be either strings or arrays with an id key.' ), '6.5.0' );
}
}
$this->registered[ $id ] = array(
'src' => $src,
'version' => $version,
'enqueue' => isset( $this->enqueued_before_registered[ $id ] ),
'dependencies' => $dependencies,
);
}
}
/**
* Marks the script module to be enqueued in the page.
*
* If a src is provided and the script module has not been registered yet, it
* will be registered.
*
* @since 6.5.0
*
* @param string $id The identifier of the script module. Should be unique. It will be used in the
* final import map.
* @param string $src Optional. Full URL of the script module, or path of the script module relative
* to the WordPress root directory. If it is provided and the script module has
* not been registered yet, it will be registered.
* @param array $deps {
* Optional. List of dependencies.
*
* @type string|array ...$0 {
* An array of script module identifiers of the dependencies of this script
* module. The dependencies can be strings or arrays. If they are arrays,
* they need an `id` key with the script module identifier, and can contain
* an `import` key with either `static` or `dynamic`. By default,
* dependencies that don't contain an `import` key are considered static.
*
* @type string $id The script module identifier.
* @type string $import Optional. Import type. May be either `static` or
* `dynamic`. Defaults to `static`.
* }
* }
* @param string|false|null $version Optional. String specifying the script module version number. Defaults to false.
* It is added to the URL as a query string for cache busting purposes. If $version
* is set to false, the version number is the currently installed WordPress version.
* If $version is set to null, no version is added.
*/
public function enqueue( string $id, string $src = '', array $deps = array(), $version = false ) {
if ( isset( $this->registered[ $id ] ) ) {
$this->registered[ $id ]['enqueue'] = true;
} elseif ( $src ) {
$this->register( $id, $src, $deps, $version );
$this->registered[ $id ]['enqueue'] = true;
} else {
$this->enqueued_before_registered[ $id ] = true;
}
}
/**
* Unmarks the script module so it will no longer be enqueued in the page.
*
* @since 6.5.0
*
* @param string $id The identifier of the script module.
*/
public function dequeue( string $id ) {
if ( isset( $this->registered[ $id ] ) ) {
$this->registered[ $id ]['enqueue'] = false;
}
unset( $this->enqueued_before_registered[ $id ] );
}
/**
* Removes a registered script module.
*
* @since 6.5.0
*
* @param string $id The identifier of the script module.
*/
public function deregister( string $id ) {
unset( $this->registered[ $id ] );
unset( $this->enqueued_before_registered[ $id ] );
}
/**
* Adds the hooks to print the import map, enqueued script modules and script
* module preloads.
*
* In classic themes, the script modules used by the blocks are not yet known
* when the `wp_head` actions is fired, so it needs to print everything in the
* footer.
*
* @since 6.5.0
*/
public function add_hooks() {
$position = wp_is_block_theme() ? 'wp_head' : 'wp_footer';
add_action( $position, array( $this, 'print_import_map' ) );
add_action( $position, array( $this, 'print_enqueued_script_modules' ) );
add_action( $position, array( $this, 'print_script_module_preloads' ) );
add_action( 'admin_print_footer_scripts', array( $this, 'print_import_map' ) );
add_action( 'admin_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ) );
add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_preloads' ) );
}
/**
* Prints the enqueued script modules using script tags with type="module"
* attributes.
*
* @since 6.5.0
*/
public function print_enqueued_script_modules() {
foreach ( $this->get_marked_for_enqueue() as $id => $script_module ) {
wp_print_script_tag(
array(
'type' => 'module',
'src' => $this->get_src( $id ),
'id' => $id . '-js-module',
)
);
}
}
/**
* Prints the the static dependencies of the enqueued script modules using
* link tags with rel="modulepreload" attributes.
*
* If a script module is marked for enqueue, it will not be preloaded.
*
* @since 6.5.0
*/
public function print_script_module_preloads() {
foreach ( $this->get_dependencies( array_keys( $this->get_marked_for_enqueue() ), array( 'static' ) ) as $id => $script_module ) {
// Don't preload if it's marked for enqueue.
if ( true !== $script_module['enqueue'] ) {
echo sprintf(
'<link rel="modulepreload" href="%s" id="%s">',
esc_url( $this->get_src( $id ) ),
esc_attr( $id . '-js-modulepreload' )
);
}
}
}
/**
* Prints the import map using a script tag with a type="importmap" attribute.
*
* @since 6.5.0
*
* @global WP_Scripts $wp_scripts The WP_Scripts object for printing the polyfill.
*/
public function print_import_map() {
$import_map = $this->get_import_map();
if ( ! empty( $import_map['imports'] ) ) {
global $wp_scripts;
if ( isset( $wp_scripts ) ) {
wp_print_inline_script_tag(
wp_get_script_polyfill(
$wp_scripts,
array(
'HTMLScriptElement.supports && HTMLScriptElement.supports("importmap")' => 'wp-polyfill-importmap',
)
),
array(
'id' => 'wp-load-polyfill-importmap',
)
);
}
wp_print_inline_script_tag(
wp_json_encode( $import_map, JSON_HEX_TAG | JSON_HEX_AMP ),
array(
'type' => 'importmap',
'id' => 'wp-importmap',
)
);
}
}
/**
* Returns the import map array.
*
* @since 6.5.0
*
* @return array Array with an `imports` key mapping to an array of script module identifiers and their respective
* URLs, including the version query.
*/
private function get_import_map(): array {
$imports = array();
foreach ( $this->get_dependencies( array_keys( $this->get_marked_for_enqueue() ) ) as $id => $script_module ) {
$imports[ $id ] = $this->get_src( $id );
}
return array( 'imports' => $imports );
}
/**
* Retrieves the list of script modules marked for enqueue.
*
* @since 6.5.0
*
* @return array[] Script modules marked for enqueue, keyed by script module identifier.
*/
private function get_marked_for_enqueue(): array {
$enqueued = array();
foreach ( $this->registered as $id => $script_module ) {
if ( true === $script_module['enqueue'] ) {
$enqueued[ $id ] = $script_module;
}
}
return $enqueued;
}
/**
* Retrieves all the dependencies for the given script module identifiers,
* filtered by import types.
*
* It will consolidate an array containing a set of unique dependencies based
* on the requested import types: 'static', 'dynamic', or both. This method is
* recursive and also retrieves dependencies of the dependencies.
*
* @since 6.5.0
*
* @param string[] $ids The identifiers of the script modules for which to gather dependencies.
* @param string[] $import_types Optional. Import types of dependencies to retrieve: 'static', 'dynamic', or both.
* Default is both.
* @return array[] List of dependencies, keyed by script module identifier.
*/
private function get_dependencies( array $ids, array $import_types = array( 'static', 'dynamic' ) ) {
return array_reduce(
$ids,
function ( $dependency_script_modules, $id ) use ( $import_types ) {
$dependencies = array();
foreach ( $this->registered[ $id ]['dependencies'] as $dependency ) {
if (
in_array( $dependency['import'], $import_types, true ) &&
isset( $this->registered[ $dependency['id'] ] ) &&
! isset( $dependency_script_modules[ $dependency['id'] ] )
) {
$dependencies[ $dependency['id'] ] = $this->registered[ $dependency['id'] ];
}
}
return array_merge( $dependency_script_modules, $dependencies, $this->get_dependencies( array_keys( $dependencies ), $import_types ) );
},
array()
);
}
/**
* Gets the versioned URL for a script module src.
*
* If $version is set to false, the version number is the currently installed
* WordPress version. If $version is set to null, no version is added.
* Otherwise, the string passed in $version is used.
*
* @since 6.5.0
*
* @param string $id The script module identifier.
* @return string The script module src with a version if relevant.
*/
private function get_src( string $id ): string {
if ( ! isset( $this->registered[ $id ] ) ) {
return '';
}
$script_module = $this->registered[ $id ];
$src = $script_module['src'];
if ( false === $script_module['version'] ) {
$src = add_query_arg( 'ver', get_bloginfo( 'version' ), $src );
} elseif ( null !== $script_module['version'] ) {
$src = add_query_arg( 'ver', $script_module['version'], $src );
}
/**
* Filters the script module source.
*
* @since 6.5.0
*
* @param string $src Module source URL.
* @param string $id Module identifier.
*/
$src = apply_filters( 'script_module_loader_src', $src, $id );
return $src;
}
}