register_core_block_style_handles

註冊核心程式碼區塊樣式控制代碼。

雖然{@see}通常用於此目的，但其實現方式對於核心程式碼塊樣式來說效率不高。在這裡註冊這些樣式控制代碼可以避免在其他函式中進行不必要的邏輯和檔案系統查詢。

function register_core_block_style_handles() {
	global $wp_version;

	if ( ! wp_should_load_separate_core_block_assets() ) {
		return;
	}

	$blocks_url   = includes_url( 'blocks/' );
	$suffix       = wp_scripts_get_suffix();
	$wp_styles    = wp_styles();
	$style_fields = array(
		'style'       => 'style',
		'editorStyle' => 'editor',
	);

	static $core_blocks_meta;
	if ( ! $core_blocks_meta ) {
		$core_blocks_meta = require BLOCKS_PATH . 'blocks-json.php';
	}

	$files          = false;
	$transient_name = 'wp_core_block_css_files';

	/*
	 * Ignore transient cache when the development mode is set to 'core'. Why? To avoid interfering with
	 * the core developer's workflow.
	 */
	$can_use_cached = ! wp_is_development_mode( 'core' );

	if ( $can_use_cached ) {
		$cached_files = get_transient( $transient_name );

		// Check the validity of cached values by checking against the current WordPress version.
		if (
			is_array( $cached_files )
			&& isset( $cached_files['version'] )
			&& $cached_files['version'] === $wp_version
			&& isset( $cached_files['files'] )
		) {
			$files = $cached_files['files'];
		}
	}

	if ( ! $files ) {
		$files = glob( wp_normalize_path( BLOCKS_PATH . '**/**.css' ) );

		// Normalize BLOCKS_PATH prior to substitution for Windows environments.
		$normalized_blocks_path = wp_normalize_path( BLOCKS_PATH );

		$files = array_map(
			static function ( $file ) use ( $normalized_blocks_path ) {
				return str_replace( $normalized_blocks_path, '', $file );
			},
			$files
		);

		// Save core block style paths in cache when not in development mode.
		if ( $can_use_cached ) {
			set_transient(
				$transient_name,
				array(
					'version' => $wp_version,
					'files'   => $files,
				)
			);
		}
	}

	$register_style = static function ( $name, $filename, $style_handle ) use ( $blocks_url, $suffix, $wp_styles, $files ) {
		$style_path = "{$name}/{$filename}{$suffix}.css";
		$path       = wp_normalize_path( BLOCKS_PATH . $style_path );

		if ( ! in_array( $style_path, $files, true ) ) {
			$wp_styles->add(
				$style_handle,
				false
			);
			return;
		}

		$wp_styles->add( $style_handle, $blocks_url . $style_path );
		$wp_styles->add_data( $style_handle, 'path', $path );

		$rtl_file = "{$name}/{$filename}-rtl{$suffix}.css";
		if ( is_rtl() && in_array( $rtl_file, $files, true ) ) {
			$wp_styles->add_data( $style_handle, 'rtl', 'replace' );
			$wp_styles->add_data( $style_handle, 'suffix', $suffix );
			$wp_styles->add_data( $style_handle, 'path', str_replace( "{$suffix}.css", "-rtl{$suffix}.css", $path ) );
		}
	};

	foreach ( $core_blocks_meta as $name => $schema ) {
		/** This filter is documented in wp-includes/blocks.php */
		$schema = apply_filters( 'block_type_metadata', $schema );

		// Backfill these properties similar to `register_block_type_from_metadata()`.
		if ( ! isset( $schema['style'] ) ) {
			$schema['style'] = "wp-block-{$name}";
		}
		if ( ! isset( $schema['editorStyle'] ) ) {
			$schema['editorStyle'] = "wp-block-{$name}-editor";
		}

		// Register block theme styles.
		$register_style( $name, 'theme', "wp-block-{$name}-theme" );

		foreach ( $style_fields as $style_field => $filename ) {
			$style_handle = $schema[ $style_field ];
			if ( is_array( $style_handle ) ) {
				continue;
			}
			$register_style( $name, $filename, $style_handle );
		}
	}
}