Prepare for new block variations 3/3: block variation loading

includes/core/classes/class-assets.php

@@ -12,7 +12,9 @@
 // Exit if accessed directly.
 defined( 'ABSPATH' ) || exit; // @codeCoverageIgnore
 
+use GatherPress\Core\Block;
 use GatherPress\Core\Traits\Singleton;
+use Error;
 
 /**
  * Class Assets.
@@ -87,6 +89,8 @@ protected function setup_hooks(): void {
 		add_action( 'admin_enqueue_scripts', array( $this, 'admin_enqueue_scripts' ) );
 		add_action( 'enqueue_block_assets', array( $this, 'enqueue_scripts' ) );
 		add_action( 'enqueue_block_editor_assets', array( $this, 'editor_enqueue_scripts' ) );
+		add_action( 'enqueue_block_editor_assets', array( $this, 'enqueue_variation_assets' ) );
+		add_action( 'init', array( $this, 'register_variation_assets' ) );
 		add_action( 'wp_head', array( $this, 'add_global_object' ), PHP_INT_MIN );
 		// Set priority to 11 to not conflict with media modal.
 		add_action( 'admin_footer', array( $this, 'event_communication_modal' ), 11 );
@@ -418,14 +422,144 @@ protected function unregister_blocks(): array {
 	 *
 	 * @since 1.0.0
 	 *
-	 * @param string $asset The file name of the asset.
+	 * @param string  $asset The file name of the asset.
+	 * @param ?string $path  (Optional) The absolute path to the asset file
+	 *                       or null to use the path based on the default naming scheme.
 	 * @return array An array containing asset-related data.
 	 */
-	protected function get_asset_data( string $asset ): array {
+	protected function get_asset_data( string $asset, string $path = null ): array {
+		$path = $path ?? $this->path . sprintf( '%s.asset.php', $asset );
 		if ( empty( $this->asset_data[ $asset ] ) ) {
-			$this->asset_data[ $asset ] = require_once $this->path . sprintf( '%s.asset.php', $asset );
+			$this->asset_data[ $asset ] = require_once $path;
 		}
 
 		return (array) $this->asset_data[ $asset ];
 	}
+
+	/**
+	 * Register all assets.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return void
+	 */
+	public function register_variation_assets(): void {
+		array_map(
+			array( $this, 'register_asset' ),
+			Block::get_instance()->get_block_variations()
+		);
+	}
+
+	/**
+	 * Enqueue all assets.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return void
+	 */
+	public function enqueue_variation_assets(): void {
+		array_map(
+			array( $this, 'enqueue_asset' ),
+			Block::get_instance()->get_block_variations()
+		);
+	}
+
+	/**
+	 * Register a new script and sets translated strings for the script.
+
+	 * @since 1.0.0
+	 *
+	 * @param string $folder_name Slug of the block to register scripts and translations for.
+	 * @param string $build_dir Name of the folder ro register assets from, relative to the plugins root directory.
+	 *
+	 * @return void
+	 */
+	protected function register_asset( string $folder_name, $build_dir = 'variations/' ): void {
+		$slug     = sprintf( 'gatherpress-%s', $folder_name );
+		$folders  = sprintf( '%1$s%2$s', $build_dir, $folder_name );
+		$dir      = sprintf( '%1$s%2$s', $this->path, $folders );
+		$path_php = sprintf( '%1$s/index.asset.php', $dir );
+		$path_css = sprintf( '%1$s/index.css', $dir );
+		$url_js   = sprintf( '%s/index.js', $this->build );
+		$url_css  = sprintf( '%s/index.css', $this->build );
+
+		if ( ! $this->asset_exists( $path_php, $folder_name ) ) {
+			return;
+		}
+
+		$asset = $this->get_asset_data( $folder_name, $path_php );
+
+		wp_register_script(
+			$slug,
+			$url_js,
+			$asset['dependencies'],
+			$asset['version'],
+			true
+		);
+
+		wp_set_script_translations( $slug, 'gatherpress' );
+
+		if ( $this->asset_exists( $path_css, $folder_name ) ) {
+			wp_register_style(
+				$slug,
+				$url_css,
+				array( 'global-styles' ),
+				$asset['version'],
+				'screen'
+			);
+		}
+	}
+
+	/**
+	 * Enqueue a script and a style with the same name, if registered.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param  string $folder_name Slug of the block to load the frontend scripts for.
+	 *
+	 * @return void
+	 */
+	protected function enqueue_asset( string $folder_name ): void {
+		$slug = sprintf( 'gatherpress-%s', $folder_name );
+		wp_enqueue_script( $slug );
+
+		if ( wp_style_is( $slug, 'registered' ) ) {
+			wp_enqueue_style( $slug );
+		}
+	}
+
+	/**
+	 * A better file_exists with built-in error handling.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @throws Error Throws error for non-existent file with given path,
+	 *               if this is a development environment,
+	 *               returns false for all other environments.
+	 *
+	 * @param  string $path Absolute path to the file to check.
+	 * @param  string $name Name of the file.
+	 *
+	 * @return bool
+	 */
+	protected function asset_exists( string $path, string $name ): bool {
+		if ( ! file_exists( $path ) ) {
+			$error_message = sprintf(
+				/* Translators: %s Name of a block-asset */
+				__(
+					'You need to run `npm start` or `npm run build` for the "%s" block-asset first.',
+					'gatherpress'
+				),
+				$name
+			);
+
+			if ( in_array( wp_get_environment_type(), array( 'local', 'development' ), true ) ) {
+				throw new Error( esc_html( $error_message ) );
+			} else {
+				// Should write to the \error_log( $error_message ); if possible.
+				return false;
+			}
+		}
+		return true;
+	}
 }

includes/core/classes/class-autoloader.php

@@ -87,6 +87,7 @@ static function ( string $class_string = '' ): void {
 					array_unshift( $structure, 'includes' );
 
 					switch ( $class_type ) {
+						case 'blocks':
 						case 'commands':
 						case 'settings':
 						case 'traits':

includes/core/classes/class-block.php

@@ -28,6 +28,14 @@ class Block {
 	 */
 	use Singleton;
 
+	/**
+	 * An array used to cache block variation names.
+	 *
+	 * @since 1.0.0
+	 * @var array
+	 */
+	protected array $block_variation_names = array();
+
 	/**
 	 * Class constructor.
 	 *
@@ -49,6 +57,8 @@ protected function __construct() {
 	 * @return void
 	 */
 	protected function setup_hooks(): void {
+		// Priority 9 needed to allow the Block_Variation(s) to register their assets on init:10, without worries.
+		add_action( 'init', array( $this, 'register_block_variations' ), 9 );
 		add_action( 'init', array( $this, 'register_block_patterns' ) );
 		// Priority 11 needed for block.json translations of title and description.
 		add_action( 'init', array( $this, 'register_blocks' ), 11 );
@@ -74,6 +84,70 @@ public function register_blocks(): void {
 		}
 	}
 
+	/**
+	 * Require files & instantiate block-variation classes.
+	 *
+	 * @return void
+	 */
+	public function register_block_variations(): void {
+		foreach ( $this->get_block_variations() as $block ) {
+			// Prepare namespaced class-name
+			// in the following shape: "GatherPress\Core\Blocks\Block_Variation"  (example).
+			$name = join(
+				'\\',
+				array(
+					__NAMESPACE__,
+					'Blocks',
+					$this->get_classname_from_foldername( $block ),
+				)
+			);
+
+			if ( class_exists( $name ) ) {
+				$name::get_instance();
+			}
+		}
+	}
+
+	/**
+	 * Get a list of subfolder names from the /build/variations/ directory.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return string[] List of block-variations foldernames.
+	 */
+	public function get_block_variations(): array {
+		$variations_directory = sprintf( '%1$s/build/variations/', GATHERPRESS_CORE_PATH );
+
+		if ( ! file_exists( $variations_directory ) ) {
+			return array();
+		}
+
+		if ( empty( $this->block_variation_names ) ) {
+			$this->block_variation_names = array_values(
+				array_diff(
+					scandir( $variations_directory ),
+					array( '..', '.' )
+				)
+			);
+		}
+		return array_filter( $this->block_variation_names );
+	}
+
+	/**
+	 * Get class name from folder name.
+	 *
+	 * @todo maybe better in the Utility class?
+	 *
+	 * @param  string $foldername String with name of a folder.
+	 *
+	 * @return string Class name that reflects the given foldername.
+	 */
+	protected static function get_classname_from_foldername( string $foldername ): string {
+		$foldername = basename( $foldername );
+
+		return ucwords( str_replace( '-', '_', $foldername ), '_' );
+	}
+
 	/**
 	 * Register block patterns.
 	 *