BlockTemplateController (woocommerce#4981)

* BlockTemplateController

* Check if theme already has template

* ThemeUtils file to check for FSE enabled themes

* Use Gutenberg global gutenberg_supports_block_templates

* Remove ThemeUtils reference

* Update with code review comments

* Delete ThemeUtils and move supports_block_templates check

* Duplicate functions from Gutenberg into Utils file

* Remove template file

* Check template directory and stylesheet directory for template

src/BlockTemplatesController.php

@@ -0,0 +1,106 @@
+<?php
+namespace Automattic\WooCommerce\Blocks;
+
+use Automattic\WooCommerce\Blocks\Utils\BlockTemplateUtils;
+
+/**
+ * BlockTypesController class.
+ *
+ * @internal
+ */
+class BlockTemplatesController {
+
+	/**
+	 * Holds the path for the directory where the block templates will be kept.
+	 *
+	 * @var string
+	 */
+	private $templates_directory;
+
+	/**
+	 * Directory name of the block template directory.
+	 *
+	 * @var string
+	 */
+	const TEMPLATES_DIR_NAME = 'block-templates';
+
+	/**
+	 * Constructor.
+	 */
+	public function __construct() {
+		$this->templates_directory = plugin_dir_path( __DIR__ ) . 'templates/' . self::TEMPLATES_DIR_NAME;
+		$this->init();
+	}
+
+	/**
+	 * Initialization method.
+	 */
+	protected function init() {
+		add_filter( 'get_block_templates', array( $this, 'add_block_templates' ), 10, 3 );
+	}
+
+	/**
+	 * Add the block template objects to be used.
+	 *
+	 * @param array $query_result Array of template objects.
+	 * @return array
+	 */
+	public function add_block_templates( $query_result ) {
+		if ( ! gutenberg_supports_block_templates() ) {
+			return $query_result;
+		}
+
+		$template_files = $this->get_block_templates();
+
+		foreach ( $template_files as $template_file ) {
+			$query_result[] = BlockTemplateUtils::gutenberg_build_template_result_from_file( $template_file, 'wp_template' );
+		}
+
+		return $query_result;
+	}
+
+	/**
+	 * Get and build the block template objects from the block template files.
+	 *
+	 * @return array
+	 */
+	public function get_block_templates() {
+		$template_files = BlockTemplateUtils::gutenberg_get_template_paths( $this->templates_directory );
+		$templates      = array();
+
+		foreach ( $template_files as $template_file ) {
+			$template_slug = substr(
+				$template_file,
+				strpos( $template_file, self::TEMPLATES_DIR_NAME . DIRECTORY_SEPARATOR ) + 1 + strlen( self::TEMPLATES_DIR_NAME ),
+				-5
+			);
+
+			// If the theme already has a template then there is no need to load ours in.
+			if ( $this->theme_has_template( $template_slug ) ) {
+				continue;
+			}
+
+			$new_template_item = array(
+				'title' => ucwords( str_replace( '-', ' ', $template_slug ) ),
+				'slug'  => $template_slug,
+				'path'  => $template_file,
+				'theme' => get_template_directory(),
+				'type'  => 'wp_template',
+			);
+			$templates[]       = $new_template_item;
+		}
+
+		return $templates;
+	}
+
+	/**
+	 * Check if the theme has a template. So we know if to load our own in or not.
+	 *
+	 * @param string $template_name name of the template file without .html extension e.g. 'single-product'.
+	 * @return boolean
+	 */
+	public function theme_has_template( $template_name ) {
+		return is_readable( get_template_directory() . '/block-templates/' . $template_name . '.html' ) ||
+			is_readable( get_stylesheet_directory() . '/block-templates/' . $template_name . '.html' );
+	}
+}

src/Domain/Bootstrap.php

@@ -5,6 +5,7 @@
 use Automattic\WooCommerce\Blocks\Assets\Api as AssetApi;
 use Automattic\WooCommerce\Blocks\Assets\AssetDataRegistry;
 use Automattic\WooCommerce\Blocks\BlockTypesController;
+use Automattic\WooCommerce\Blocks\BlockTemplatesController;
 use Automattic\WooCommerce\Blocks\InboxNotifications;
 use Automattic\WooCommerce\Blocks\Installer;
 use Automattic\WooCommerce\Blocks\Registry\Container;
@@ -101,6 +102,9 @@ function() {
 		$this->container->get( RestApi::class );
 		$this->container->get( GoogleAnalytics::class );
 		$this->container->get( BlockTypesController::class );
+		if ( $this->package->feature()->is_experimental_build() ) {
+			$this->container->get( BlockTemplatesController::class );
+		}
 		if ( $this->package->feature()->is_feature_plugin_build() ) {
 			$this->container->get( PaymentsApi::class );
 		}
@@ -227,6 +231,14 @@ function ( Container $container ) {
 				return new BlockTypesController( $asset_api, $asset_data_registry );
 			}
 		);
+		if ( $this->package->feature()->is_experimental_build() ) {
+			$this->container->register(
+				BlockTemplatesController::class,
+				function ( Container $container ) {
+					return new BlockTemplatesController();
+				}
+			);
+		}
 		$this->container->register(
 			DraftOrders::class,
 			function( Container $container ) {

src/Utils/BlockTemplateUtils.php

@@ -0,0 +1,131 @@
+<?php
+namespace Automattic\WooCommerce\Blocks\Utils;
+
+/**
+ * BlockTemplateUtils class used for serving block templates from Woo Blocks.
+ * IMPORTANT: These methods have been duplicated from Gutenberg/lib/full-site-editing/block-templates.php as those functions are not for public usage.
+ */
+class BlockTemplateUtils {
+	/**
+	 * Returns an array containing the references of
+	 * the passed blocks and their inner blocks.
+	 *
+	 * @param array $blocks array of blocks.
+	 *
+	 * @return array block references to the passed blocks and their inner blocks.
+	 */
+	public static function gutenberg_flatten_blocks( &$blocks ) {
+		$all_blocks = array();
+		$queue      = array();
+		foreach ( $blocks as &$block ) {
+			$queue[] = &$block;
+		}
+		$queue_count = count( $queue );
+
+		while ( $queue_count > 0 ) {
+			$block = &$queue[0];
+			array_shift( $queue );
+			$all_blocks[] = &$block;
+
+			if ( ! empty( $block['innerBlocks'] ) ) {
+				foreach ( $block['innerBlocks'] as &$inner_block ) {
+					$queue[] = &$inner_block;
+				}
+			}
+
+			$queue_count = count( $queue );
+		}
+
+		return $all_blocks;
+	}
+
+	/**
+	 * Parses wp_template content and injects the current theme's
+	 * stylesheet as a theme attribute into each wp_template_part
+	 *
+	 * @param string $template_content serialized wp_template content.
+	 *
+	 * @return string Updated wp_template content.
+	 */
+	public static function gutenberg_inject_theme_attribute_in_content( $template_content ) {
+		$has_updated_content = false;
+		$new_content         = '';
+		$template_blocks     = parse_blocks( $template_content );
+
+		$blocks = self::gutenberg_flatten_blocks( $template_blocks );
+		foreach ( $blocks as &$block ) {
+			if (
+				'core/template-part' === $block['blockName'] &&
+				! isset( $block['attrs']['theme'] )
+			) {
+				$block['attrs']['theme'] = wp_get_theme()->get_stylesheet();
+				$has_updated_content     = true;
+			}
+		}
+
+		if ( $has_updated_content ) {
+			foreach ( $template_blocks as &$block ) {
+				$new_content .= serialize_block( $block );
+			}
+
+			return $new_content;
+		}
+
+		return $template_content;
+	}
+
+	/**
+	 * Build a unified template object based on a theme file.
+	 *
+	 * @param array $template_file Theme file.
+	 * @param array $template_type wp_template or wp_template_part.
+	 *
+	 * @return WP_Block_Template Template.
+	 */
+	public static function gutenberg_build_template_result_from_file( $template_file, $template_type ) {
+		$default_template_types = gutenberg_get_default_template_types();
+		// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents
+		$template_content = file_get_contents( $template_file['path'] );
+		$theme            = wp_get_theme()->get_stylesheet();
+
+		$template                 = new \WP_Block_Template();
+		$template->id             = $theme . '//' . $template_file['slug'];
+		$template->theme          = $theme;
+		$template->content        = self::gutenberg_inject_theme_attribute_in_content( $template_content );
+		$template->slug           = $template_file['slug'];
+		$template->source         = 'theme';
+		$template->type           = $template_type;
+		$template->title          = ! empty( $template_file['title'] ) ? $template_file['title'] : $template_file['slug'];
+		$template->status         = 'publish';
+		$template->has_theme_file = true;
+
+		if ( 'wp_template' === $template_type && isset( $default_template_types[ $template_file['slug'] ] ) ) {
+			$template->description = $default_template_types[ $template_file['slug'] ]['description'];
+			$template->title       = $default_template_types[ $template_file['slug'] ]['title'];
+		}
+
+		if ( 'wp_template_part' === $template_type && isset( $template_file['area'] ) ) {
+			$template->area = $template_file['area'];
+		}
+
+		return $template;
+	}
+
+	/**
+	 * Finds all nested template part file paths in a theme's directory.
+	 *
+	 * @param string $base_directory The theme's file path.
+	 * @return array $path_list A list of paths to all template part files.
+	 */
+	public static function gutenberg_get_template_paths( $base_directory ) {
+		$path_list = array();
+		if ( file_exists( $base_directory ) ) {
+			$nested_files      = new \RecursiveIteratorIterator( new \RecursiveDirectoryIterator( $base_directory ) );
+			$nested_html_files = new \RegexIterator( $nested_files, '/^.+\.html$/i', \RecursiveRegexIterator::GET_MATCH );
+			foreach ( $nested_html_files as $path => $file ) {
+				$path_list[] = $path;
+			}
+		}
+		return $path_list;
+	}
+}