_register_theme_block_patterns

_register_theme_block_patterns: 这个函数用来注册属于一个主题的区块模式。它通常在after_setup_theme动作钩子中调用。

在`./patterns/`目录下注册活动主题可能提供的任何样板。每个模式都被定义为一个PHP文件，并使用插件式的头文件来定义其元数据。最低要求的定义是：

/**
* Title: My Pattern
* Slug: my-theme/my-pattern
*

PHP源的输出与该样板的内容相对应，例如：

如果适用，这将从父主题和子主题收集。

其他可设置的字段包括：

– Description
– Viewport Width
– Categories (comma-separated values)
– Keywords (comma-separated values)
– Block Types (comma-separated values)
– Post Types (comma-separated values)
– Inserter (yes/no)

function _register_theme_block_patterns() {
	$default_headers = array(
		'title'         => 'Title',
		'slug'          => 'Slug',
		'description'   => 'Description',
		'viewportWidth' => 'Viewport Width',
		'categories'    => 'Categories',
		'keywords'      => 'Keywords',
		'blockTypes'    => 'Block Types',
		'postTypes'     => 'Post Types',
		'inserter'      => 'Inserter',
	);

	/*
	 * Register patterns for the active theme. If the theme is a child theme,
	 * let it override any patterns from the parent theme that shares the same slug.
	 */
	$themes     = array();
	$stylesheet = get_stylesheet();
	$template   = get_template();
	if ( $stylesheet !== $template ) {
		$themes[] = wp_get_theme( $stylesheet );
	}
	$themes[] = wp_get_theme( $template );

	foreach ( $themes as $theme ) {
		$dirpath = $theme->get_stylesheet_directory() . '/patterns/';
		if ( ! is_dir( $dirpath ) || ! is_readable( $dirpath ) ) {
			continue;
		}
		if ( file_exists( $dirpath ) ) {
			$files = glob( $dirpath . '*.php' );
			if ( $files ) {
				foreach ( $files as $file ) {
					$pattern_data = get_file_data( $file, $default_headers );

					if ( empty( $pattern_data['slug'] ) ) {
						_doing_it_wrong(
							'_register_theme_block_patterns',
							sprintf(
								/* translators: %s: file name. */
								__( 'Could not register file "%s" as a block pattern ("Slug" field missing)' ),
								$file
							),
							'6.0.0'
						);
						continue;
					}

					if ( ! preg_match( '/^[A-z0-9/_-]+$/', $pattern_data['slug'] ) ) {
						_doing_it_wrong(
							'_register_theme_block_patterns',
							sprintf(
								/* translators: %1s: file name; %2s: slug value found. */
								__( 'Could not register file "%1$s" as a block pattern (invalid slug "%2$s")' ),
								$file,
								$pattern_data['slug']
							),
							'6.0.0'
						);
					}

					if ( WP_Block_Patterns_Registry::get_instance()->is_registered( $pattern_data['slug'] ) ) {
						continue;
					}

					// Title is a required property.
					if ( ! $pattern_data['title'] ) {
						_doing_it_wrong(
							'_register_theme_block_patterns',
							sprintf(
								/* translators: %1s: file name; %2s: slug value found. */
								__( 'Could not register file "%s" as a block pattern ("Title" field missing)' ),
								$file
							),
							'6.0.0'
						);
						continue;
					}

					// For properties of type array, parse data as comma-separated.
					foreach ( array( 'categories', 'keywords', 'blockTypes', 'postTypes' ) as $property ) {
						if ( ! empty( $pattern_data[ $property ] ) ) {
							$pattern_data[ $property ] = array_filter(
								preg_split(
									'/[s,]+/',
									(string) $pattern_data[ $property ]
								)
							);
						} else {
							unset( $pattern_data[ $property ] );
						}
					}

					// Parse properties of type int.
					foreach ( array( 'viewportWidth' ) as $property ) {
						if ( ! empty( $pattern_data[ $property ] ) ) {
							$pattern_data[ $property ] = (int) $pattern_data[ $property ];
						} else {
							unset( $pattern_data[ $property ] );
						}
					}

					// Parse properties of type bool.
					foreach ( array( 'inserter' ) as $property ) {
						if ( ! empty( $pattern_data[ $property ] ) ) {
							$pattern_data[ $property ] = in_array(
								strtolower( $pattern_data[ $property ] ),
								array( 'yes', 'true' ),
								true
							);
						} else {
							unset( $pattern_data[ $property ] );
						}
					}

					// Translate the pattern metadata.
					$text_domain = $theme->get( 'TextDomain' );
					//phpcs:ignore WordPress.WP.I18n.NonSingularStringLiteralText, WordPress.WP.I18n.NonSingularStringLiteralContext, WordPress.WP.I18n.NonSingularStringLiteralDomain, WordPress.WP.I18n.LowLevelTranslationFunction
					$pattern_data['title'] = translate_with_gettext_context( $pattern_data['title'], 'Pattern title', $text_domain );
					if ( ! empty( $pattern_data['description'] ) ) {
						//phpcs:ignore WordPress.WP.I18n.NonSingularStringLiteralText, WordPress.WP.I18n.NonSingularStringLiteralContext, WordPress.WP.I18n.NonSingularStringLiteralDomain, WordPress.WP.I18n.LowLevelTranslationFunction
						$pattern_data['description'] = translate_with_gettext_context( $pattern_data['description'], 'Pattern description', $text_domain );
					}

					// The actual pattern content is the output of the file.
					ob_start();
					include $file;
					$pattern_data['content'] = ob_get_clean();
					if ( ! $pattern_data['content'] ) {
						continue;
					}

					register_block_pattern( $pattern_data['slug'], $pattern_data );
				}
			}
		}
	}
}