wp_render_layout_support_flag

wp_render_layout_support_flag: 這個函式為一個文章型別新增一個佈局支援標誌。這個標誌允許主題開發者定義一個文章型別的佈局，例如，全寬的、盒式的或側邊欄。

將佈局配置渲染到區塊包裝器上。

function wp_render_layout_support_flag( $block_content, $block ) {
	$block_type     = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
	$support_layout = block_has_support( $block_type, array( '__experimentalLayout' ), false );

	if ( ! $support_layout ) {
		return $block_content;
	}

	$block_gap              = wp_get_global_settings( array( 'spacing', 'blockGap' ) );
	$global_layout_settings = wp_get_global_settings( array( 'layout' ) );
	$has_block_gap_support  = isset( $block_gap ) ? null !== $block_gap : false;
	$default_block_layout   = _wp_array_get( $block_type->supports, array( '__experimentalLayout', 'default' ), array() );
	$used_layout            = isset( $block['attrs']['layout'] ) ? $block['attrs']['layout'] : $default_block_layout;

	if ( isset( $used_layout['inherit'] ) && $used_layout['inherit'] ) {
		if ( ! $global_layout_settings ) {
			return $block_content;
		}
	}

	$class_names        = array();
	$layout_definitions = _wp_array_get( $global_layout_settings, array( 'definitions' ), array() );
	$block_classname    = wp_get_block_default_classname( $block['blockName'] );
	$container_class    = wp_unique_id( 'wp-container-' );
	$layout_classname   = '';

	// Set the correct layout type for blocks using legacy content width.
	if ( isset( $used_layout['inherit'] ) && $used_layout['inherit'] || isset( $used_layout['contentSize'] ) && $used_layout['contentSize'] ) {
		$used_layout['type'] = 'constrained';
	}

	if (
		wp_get_global_settings( array( 'useRootPaddingAwareAlignments' ) ) &&
		isset( $used_layout['type'] ) &&
		'constrained' === $used_layout['type']
	) {
		$class_names[] = 'has-global-padding';
	}

	/*
	 * The following section was added to reintroduce a small set of layout classnames that were
	 * removed in the 5.9 release (https://github.com/WordPress/gutenberg/issues/38719). It is
	 * not intended to provide an extended set of classes to match all block layout attributes
	 * here.
	 */
	if ( ! empty( $block['attrs']['layout']['orientation'] ) ) {
		$class_names[] = 'is-' . sanitize_title( $block['attrs']['layout']['orientation'] );
	}

	if ( ! empty( $block['attrs']['layout']['justifyContent'] ) ) {
		$class_names[] = 'is-content-justification-' . sanitize_title( $block['attrs']['layout']['justifyContent'] );
	}

	if ( ! empty( $block['attrs']['layout']['flexWrap'] ) && 'nowrap' === $block['attrs']['layout']['flexWrap'] ) {
		$class_names[] = 'is-nowrap';
	}

	// Get classname for layout type.
	if ( isset( $used_layout['type'] ) ) {
		$layout_classname = _wp_array_get( $layout_definitions, array( $used_layout['type'], 'className' ), '' );
	} else {
		$layout_classname = _wp_array_get( $layout_definitions, array( 'default', 'className' ), '' );
	}

	if ( $layout_classname && is_string( $layout_classname ) ) {
		$class_names[] = sanitize_title( $layout_classname );
	}

	/*
	 * Only generate Layout styles if the theme has not opted-out.
	 * Attribute-based Layout classnames are output in all cases.
	 */
	if ( ! current_theme_supports( 'disable-layout-styles' ) ) {

		$gap_value = _wp_array_get( $block, array( 'attrs', 'style', 'spacing', 'blockGap' ) );
		/*
		 * Skip if gap value contains unsupported characters.
		 * Regex for CSS value borrowed from `safecss_filter_attr`, and used here
		 * to only match against the value, not the CSS attribute.
		 */
		if ( is_array( $gap_value ) ) {
			foreach ( $gap_value as $key => $value ) {
				$gap_value[ $key ] = $value && preg_match( '%[\(&=}]|/*%', $value ) ? null : $value;
			}
		} else {
			$gap_value = $gap_value && preg_match( '%[\(&=}]|/*%', $gap_value ) ? null : $gap_value;
		}

		$fallback_gap_value = _wp_array_get( $block_type->supports, array( 'spacing', 'blockGap', '__experimentalDefault' ), '0.5em' );
		$block_spacing      = _wp_array_get( $block, array( 'attrs', 'style', 'spacing' ), null );

		/*
		 * If a block's block.json skips serialization for spacing or spacing.blockGap,
		 * don't apply the user-defined value to the styles.
		 */
		$should_skip_gap_serialization = wp_should_skip_block_supports_serialization( $block_type, 'spacing', 'blockGap' );

		$style = wp_get_layout_style(
			".$block_classname.$container_class",
			$used_layout,
			$has_block_gap_support,
			$gap_value,
			$should_skip_gap_serialization,
			$fallback_gap_value,
			$block_spacing
		);

		// Only add container class and enqueue block support styles if unique styles were generated.
		if ( ! empty( $style ) ) {
			$class_names[] = $container_class;
		}
	}

	/*
	 * This assumes the hook only applies to blocks with a single wrapper.
	 * A limitation of this hook is that nested inner blocks wrappers are not yet supported.
	 */
	$content = preg_replace(
		'/' . preg_quote( 'class="', '/' ) . '/',
		'class="' . esc_attr( implode( ' ', $class_names ) ) . ' ',
		$block_content,
		1
	);

	return $content;
}