Site Export: ensure that the export endpoint uses Gutenberg theme cla…

…sses (#61561)

* This ensures that any theme exports get the benefit of the latest changes to theme json and resolver.

* check for function exists.

* Moving changes to `/lib` folder because none of the changes are backwards compat specific.
Having this extension permanently in Gutenberg means that theme.json exporting will always use the latest version of the Theme JSON family of classes.

* Add to version control would help

* Added i18n domain


Co-authored-by: ramonjd <ramonopoly@git.wordpress.org>
Co-authored-by: andrewserong <andrewserong@git.wordpress.org>

lib/block-template-utils.php

@@ -0,0 +1,114 @@
+<?php
+/**
+ * Utilities used to fetch and create templates and template parts.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Creates an export of the current templates and
+ * template parts from the site editor at the
+ * specified path in a ZIP file.
+ *
+ * @since 5.9.0
+ * @since 6.0.0 Adds the whole theme to the export archive.
+ *
+ * @global string $wp_version The WordPress version string.
+ *
+ * @return WP_Error|string Path of the ZIP file or error on failure.
+ */
+function gutenberg_generate_block_templates_export_file() {
+	global $wp_version;
+
+	if ( ! class_exists( 'ZipArchive' ) ) {
+		return new WP_Error( 'missing_zip_package', __( 'Zip Export not supported.', 'gutenberg' ) );
+	}
+
+	$obscura    = wp_generate_password( 12, false, false );
+	$theme_name = basename( get_stylesheet() );
+	$filename   = get_temp_dir() . $theme_name . $obscura . '.zip';
+
+	$zip = new ZipArchive();
+	if ( true !== $zip->open( $filename, ZipArchive::CREATE | ZipArchive::OVERWRITE ) ) {
+		return new WP_Error( 'unable_to_create_zip', __( 'Unable to open export file (archive) for writing.', 'gutenberg' ) );
+	}
+
+	$zip->addEmptyDir( 'templates' );
+	$zip->addEmptyDir( 'parts' );
+
+	// Get path of the theme.
+	$theme_path = wp_normalize_path( get_stylesheet_directory() );
+
+	// Create recursive directory iterator.
+	$theme_files = new RecursiveIteratorIterator(
+		new RecursiveDirectoryIterator( $theme_path ),
+		RecursiveIteratorIterator::LEAVES_ONLY
+	);
+
+	// Make a copy of the current theme.
+	foreach ( $theme_files as $file ) {
+		// Skip directories as they are added automatically.
+		if ( ! $file->isDir() ) {
+			// Get real and relative path for current file.
+			$file_path     = wp_normalize_path( $file );
+			$relative_path = substr( $file_path, strlen( $theme_path ) + 1 );
+
+			if ( ! wp_is_theme_directory_ignored( $relative_path ) ) {
+				$zip->addFile( $file_path, $relative_path );
+			}
+		}
+	}
+
+	// Load templates into the zip file.
+	$templates = gutenberg_get_block_templates();
+	foreach ( $templates as $template ) {
+		$template->content = traverse_and_serialize_blocks(
+			parse_blocks( $template->content ),
+			'_remove_theme_attribute_from_template_part_block'
+		);
+
+		$zip->addFromString(
+			'templates/' . $template->slug . '.html',
+			$template->content
+		);
+	}
+
+	// Load template parts into the zip file.
+	$template_parts = gutenberg_get_block_templates( array(), 'wp_template_part' );
+	foreach ( $template_parts as $template_part ) {
+		$zip->addFromString(
+			'parts/' . $template_part->slug . '.html',
+			$template_part->content
+		);
+	}
+
+	// Load theme.json into the zip file.
+	$tree = WP_Theme_JSON_Resolver_Gutenberg::get_theme_data( array(), array( 'with_supports' => false ) );
+	// Merge with user data.
+	$tree->merge( WP_Theme_JSON_Resolver_Gutenberg::get_user_data() );
+
+	$theme_json_raw = $tree->get_data();
+	// If a version is defined, add a schema.
+	if ( $theme_json_raw['version'] ) {
+		$theme_json_version = 'wp/' . substr( $wp_version, 0, 3 );
+		$schema             = array( '$schema' => 'https://schemas.wp.org/' . $theme_json_version . '/theme.json' );
+		$theme_json_raw     = array_merge( $schema, $theme_json_raw );
+	}
+
+	// Convert to a string.
+	$theme_json_encoded = wp_json_encode( $theme_json_raw, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
+
+	// Replace 4 spaces with a tab.
+	$theme_json_tabbed = preg_replace( '~(?:^|\G)\h{4}~m', "\t", $theme_json_encoded );
+
+	// Add the theme.json file to the zip.
+	$zip->addFromString(
+		'theme.json',
+		$theme_json_tabbed
+	);
+
+	// Save changes to the zip file.
+	$zip->close();
+
+	return $filename;
+}

lib/class-wp-rest-edit-site-export-controller-gutenberg.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * Controller which provides REST endpoint for exporting current templates
+ * and template parts.
+ *
+ * This class extension exists so that theme exporting takes into account any updates/changes to
+ * WP_Theme_JSON_Gutenberg, WP_Theme_JSON_Resolver_Gutenberg or related classes.
+ *
+ * @package    gutenberg
+ * @subpackage REST_API
+ * @since 5.9.0
+ */
+
+if ( class_exists( 'WP_REST_Edit_Site_Export_Controller_Gutenberg' ) ) {
+	return;
+}
+
+class WP_REST_Edit_Site_Export_Controller_Gutenberg extends WP_REST_Edit_Site_Export_Controller {
+	/**
+	 * Output a ZIP file with an export of the current templates
+	 * and template parts from the site editor, and close the connection.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @return WP_Error|void
+	 */
+	public function export() {
+		// Generate the export file.
+		$filename = gutenberg_generate_block_templates_export_file();
+
+		if ( is_wp_error( $filename ) ) {
+			$filename->add_data( array( 'status' => 500 ) );
+
+			return $filename;
+		}
+
+		$theme_name = basename( get_stylesheet() );
+		header( 'Content-Type: application/zip' );
+		header( 'Content-Disposition: attachment; filename=' . $theme_name . '.zip' );
+		header( 'Content-Length: ' . filesize( $filename ) );
+		flush();
+		readfile( $filename );
+		unlink( $filename );
+		exit;
+	}
+}

lib/load.php

@@ -53,6 +53,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 
 	// Plugin specific code.
 	require_once __DIR__ . '/class-wp-rest-global-styles-controller-gutenberg.php';
+	require_once __DIR__ . '/class-wp-rest-edit-site-export-controller-gutenberg.php';
 	require_once __DIR__ . '/rest-api.php';
 
 	// Experimental.
@@ -206,6 +207,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 require __DIR__ . '/demo.php';
 require __DIR__ . '/experiments-page.php';
 require __DIR__ . '/interactivity-api.php';
+require __DIR__ . '/block-template-utils.php';
 if ( gutenberg_is_experiment_enabled( 'gutenberg-full-page-client-side-navigation' ) ) {
 	require __DIR__ . '/experimental/full-page-client-side-navigation.php';
 }

lib/rest-api.php

@@ -18,3 +18,15 @@ function gutenberg_register_global_styles_endpoints() {
 	$global_styles_controller->register_routes();
 }
 add_action( 'rest_api_init', 'gutenberg_register_global_styles_endpoints' );
+
+if ( ! function_exists( 'gutenberg_register_edit_site_export_controller_endpoints' ) ) {
+	/**
+	 * Registers the Edit Site Export REST API routes.
+	 */
+	function gutenberg_register_edit_site_export_controller_endpoints() {
+		$edit_site_export_controller = new WP_REST_Edit_Site_Export_Controller_Gutenberg();
+		$edit_site_export_controller->register_routes();
+	}
+}
+
+add_action( 'rest_api_init', 'gutenberg_register_edit_site_export_controller_endpoints' );