Changeset 58579 for trunk/src/wp-includes/class-wp-script-modules.php

Timestamp:

06/26/2024 01:19:47 PM (4 months ago)

Author:

Bernhard Reiter

Message:

Script Modules: Add new API to embed server data in HTML.

Add a new filter script_module_data_{$module_id} to associate data
with a Script Module. For example:

add_filter(
        'script_module_data_MyScriptModuleID',
        function ( array $data ): array {
                $data['script-needs-this-data'] = 'ok';
                return $data;
        }
);

If the Script Module is included in the page, enqueued or as a
dependency, the associated data will be JSON-encoded and embedded in the
HTML in a <script type="application/json"> tag with an ID of the form
wp-script-module-data-{$module_id} allowing the Script Module to
access the data on the client.

See the original proposal: ​https://make.wordpress.org/core/2024/05/06/proposal-server-to-client-data-sharing-for-script-modules/

Developed in ​https://github.com/WordPress/wordpress-develop/pull/6682.

Props jonsurrell, cbravobernal, westonruter, gziolo, bernhard-reiter, youknowriad, sergiomdgomes, czapla.
Fixes #61510. See #60647.

File:

• trunk/src/wp-includes/class-wp-script-modules.php (modified) (2 diffs)

trunk/src/wp-includes/class-wp-script-modules.php

@@ -183 +183 @@
         add_action( 'admin_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ) );
         add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_preloads' ) );
+
+        add_action( 'wp_footer', array( $this, 'print_script_module_data' ) );
+        add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_data' ) );
     }
 
@@ -364 +367 @@
         return $src;
     }
+
+    /**
+     * Print data associated with Script Modules.
+     *
+     * The data will be embedded in the page HTML and can be read by Script Modules on page load.
+     *
+     * @since 6.7.0
+     *
+     * Data can be associated with a Script Module via the
+     * {@see "script_module_data_{$module_id}"} filter.
+     *
+     * The data for a Script Module will be serialized as JSON in a script tag with an ID of the
+     * form `wp-script-module-data-{$module_id}`.
+     */
+    public function print_script_module_data(): void {
+        $modules = array();
+        foreach ( array_keys( $this->get_marked_for_enqueue() ) as $id ) {
+            $modules[ $id ] = true;
+        }
+        foreach ( array_keys( $this->get_import_map()['imports'] ) as $id ) {
+            $modules[ $id ] = true;
+        }
+
+        foreach ( array_keys( $modules ) as $module_id ) {
+            /**
+             * Filters data associated with a given Script Module.
+             *
+             * Script Modules may require data that is required for initialization or is essential
+             * to have immediately available on page load. These are suitable use cases for
+             * this data.
+             *
+             * The dynamic portion of the hook name, `$module_id`, refers to the Script Module ID
+             * that the data is associated with.
+             *
+             * This is best suited to pass essential data that must be available to the module for
+             * initialization or immediately on page load. It does not replace the REST API or
+             * fetching data from the client.
+             *
+             * @example
+             *   add_filter(
+             *     'script_module_data_MyScriptModuleID',
+             *     function ( array $data ): array {
+             *       $data['script-needs-this-data'] = 'ok';
+             *       return $data;
+             *     }
+             *   );
+             *
+             * If the filter returns no data (an empty array), nothing will be embedded in the page.
+             *
+             * The data for a given Script Module, if provided, will be JSON serialized in a script
+             * tag with an ID of the form `wp-script-module-data-{$module_id}`.
+             *
+             * The data can be read on the client with a pattern like this:
+             *
+             * @example
+             *   const dataContainer = document.getElementById( 'wp-script-module-data-MyScriptModuleID' );
+             *   let data = {};
+             *   if ( dataContainer ) {
+             *     try {
+             *       data = JSON.parse( dataContainer.textContent );
+             *     } catch {}
+             *   }
+             *   initMyScriptModuleWithData( data );
+             *
+             * @since 6.7.0
+             *
+             * @param array $data The data associated with the Script Module.
+             */
+            $data = apply_filters( "script_module_data_{$module_id}", array() );
+
+            if ( is_array( $data ) && array() !== $data ) {
+                /*
+                 * This data will be printed as JSON inside a script tag like this:
+                 *   <script type="application/json"></script>
+                 *
+                 * A script tag must be closed by a sequence beginning with `</`. It's impossible to
+                 * close a script tag without using `<`. We ensure that `<` is escaped and `/` can
+                 * remain unescaped, so `</script>` will be printed as `\u003C/script\u00E3`.
+                 *
+                 *   - JSON_HEX_TAG: All < and > are converted to \u003C and \u003E.
+                 *   - JSON_UNESCAPED_SLASHES: Don't escape /.
+                 *
+                 * If the page will use UTF-8 encoding, it's safe to print unescaped unicode:
+                 *
+                 *   - JSON_UNESCAPED_UNICODE: Encode multibyte Unicode characters literally (instead of as `\uXXXX`).
+                 *   - JSON_UNESCAPED_LINE_TERMINATORS: The line terminators are kept unescaped when
+                 *     JSON_UNESCAPED_UNICODE is supplied. It uses the same behaviour as it was
+                 *     before PHP 7.1 without this constant. Available as of PHP 7.1.0.
+                 *
+                 * The JSON specification requires encoding in UTF-8, so if the generated HTML page
+                 * is not encoded in UTF-8 then it's not safe to include those literals. They must
+                 * be escaped to avoid encoding issues.
+                 *
+                 * @see https://www.rfc-editor.org/rfc/rfc8259.html for details on encoding requirements.
+                 * @see https://www.php.net/manual/en/json.constants.php for details on these constants.
+                 * @see https://html.spec.whatwg.org/#script-data-state for details on script tag parsing.
+                 */
+                $json_encode_flags = JSON_HEX_TAG | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_LINE_TERMINATORS;
+                if ( ! is_utf8_charset() ) {
+                    $json_encode_flags = JSON_HEX_TAG | JSON_UNESCAPED_SLASHES;
+                }
+
+                wp_print_inline_script_tag(
+                    wp_json_encode(
+                        $data,
+                        $json_encode_flags
+                    ),
+                    array(
+                        'type' => 'application/json',
+                        'id'   => "wp-script-module-data-{$module_id}",
+                    )
+                );
+            }
+        }
+    }
 }