wp_render_layout_support_flag() │ WP 5.8.0

Renders the layout config to the block wrapper.

No Hooks.

Returns

string. Filtered block content.

Usage

wp_render_layout_support_flag( $block_content, $block );

$block_content(string) (required)

Rendered block content.

$block(array) (required)

Block object.

Changelog

wp_render_layout_support_flag() wp render layout support flag code ^{WP 7.1}

function wp_render_layout_support_flag( $block_content, $block ) {
	static $global_styles = null;

	$block_type            = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
	$block_supports_layout = block_has_support( $block_type, 'layout', false ) || block_has_support( $block_type, '__experimentalLayout', false );
	$style_attr            = $block['attrs']['style'] ?? array();
	/*
	 * A block with no layout support and no style attribute at all cannot
	 * produce layout output, so return before resolving global settings.
	 *
	 * Resolving settings is not read-only: on a cold cache it queries the
	 * user's `wp_global_styles` post, which fires `the_posts`. A callback on
	 * that hook that renders blocks re-enters this filter, and the content it
	 * renders at that point is the global styles post itself, which parses to a
	 * single block with no name and no attributes. Without this return that
	 * block resolves settings again and the recursion has no base case.
	 */
	if ( ! $block_supports_layout && empty( $style_attr ) ) {
		return $block_content;
	}

	$global_settings          = wp_get_global_settings();
	$viewport_settings        = $global_settings['viewport'] ?? null;
	$responsive_media_queries = WP_Theme_JSON::get_viewport_media_queries( $viewport_settings );
	$child_layout             = $style_attr['layout'] ?? null;

	/*
	 * Collect responsive viewport child layout overrides so that a block with
	 * only responsive child layout (no base child layout) is still processed.
	 */
	$viewport_child_layouts = array();
	foreach ( $responsive_media_queries as $breakpoint => $media_query ) {
		$viewport_child = wp_get_layout_child_values( $style_attr[ $breakpoint ]['layout'] ?? null );

		if ( ! empty( $viewport_child ) ) {
			$viewport_child_layouts[ $breakpoint ] = array(
				'media_query'  => $media_query,
				'child_layout' => $viewport_child,
			);
		}
	}

	if ( ! $block_supports_layout && ! $child_layout && empty( $viewport_child_layouts ) ) {
		return $block_content;
	}

	$outer_class_names = array();

	// Child layout specific logic.
	if ( $child_layout || ! empty( $viewport_child_layouts ) ) {
		$base_child_layout = wp_get_layout_child_values( $child_layout );
		$parent_layout     = $block['parentLayout'] ?? array();
		/*
		 * Generates a unique class for child block layout styles.
		 *
		 * To ensure consistent class generation across different page renders,
		 * only properties that affect layout styling are used. These properties
		 * come from `$block['attrs']['style']['layout']`, viewport overrides in
		 * `$block['attrs']['style'][$breakpoint]['layout']`, and `$block['parentLayout']`.
		 *
		 * As long as these properties coincide, the generated class will be the same.
		 */
		$container_content_hash_input = array(
			'layout'       => $base_child_layout,
			'parentLayout' => array_intersect_key(
				$parent_layout,
				array_flip( array( 'minimumColumnWidth', 'columnCount' ) )
			),
		);

		foreach ( $viewport_child_layouts as $breakpoint => $viewport_data ) {
			$container_content_hash_input[ $breakpoint ] = $viewport_data['child_layout'];
		}

		$container_content_class = wp_unique_id_from_values(
			$container_content_hash_input,
			'wp-container-content-'
		);

		$child_layout_styles = wp_get_child_layout_style_rules( ".$container_content_class", $base_child_layout, $parent_layout );

		/*
		 * Emit responsive child layout CSS using the same container-content class
		 * so that base and responsive child layout share the exact same selector.
		 */
		foreach ( $viewport_child_layouts as $viewport_data ) {
			$viewport_child_styles = wp_get_child_layout_style_rules(
				".$container_content_class",
				$base_child_layout,
				$parent_layout,
				$viewport_data['child_layout']
			);

			foreach ( $viewport_child_styles as $index => $rule ) {
				$viewport_child_styles[ $index ]['rules_group'] = $viewport_data['media_query'];
			}

			$child_layout_styles = array_merge( $child_layout_styles, $viewport_child_styles );
		}

		/*
		 * Add to the style engine store to enqueue and render layout styles.
		 * Return styles here just to check if any exist.
		 */
		$child_css = wp_style_engine_get_stylesheet_from_css_rules(
			$child_layout_styles,
			array(
				'context'  => 'block-supports',
				'prettify' => false,
			)
		);

		if ( $child_css ) {
			$outer_class_names[] = $container_content_class;
		}
	}

	// Prep the processor for modifying the block output.
	$processor = new WP_HTML_Tag_Processor( $block_content );

	// Having no tags implies there are no tags onto which to add class names.
	if ( ! $processor->next_tag() ) {
		return $block_content;
	}

	/*
	 * A block may not support layout but still be affected by a parent block's layout.
	 *
	 * In these cases add the appropriate class names and then return early; there's
	 * no need to investigate on this block whether additional layout constraints apply.
	 */
	if ( ! $block_supports_layout && ! empty( $outer_class_names ) ) {
		foreach ( $outer_class_names as $class_name ) {
			$processor->add_class( $class_name );
		}
		return $processor->get_updated_html();
	} elseif ( ! $block_supports_layout ) {
		// Ensure layout classnames are not injected if there is no layout support.
		return $block_content;
	}

	$fallback_layout = $block_type->supports['layout']['default'] ?? array();
	if ( empty( $fallback_layout ) ) {
		$fallback_layout = $block_type->supports['__experimentalLayout']['default'] ?? array();
	}
	$used_layout = $block['attrs']['layout'] ?? $fallback_layout;

	$class_names        = array();
	$layout_definitions = wp_get_layout_definitions();

	// 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';
	}

	$root_padding_aware_alignments = $global_settings['useRootPaddingAwareAlignments'] ?? false;

	if (
		$root_padding_aware_alignments &&
		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 = $layout_definitions[ $used_layout['type'] ]['className'] ?? '';
	} else {
		$layout_classname = $layout_definitions['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_sanitize_block_gap_value( $style_attr['spacing']['blockGap'] ?? null );
		$fallback_gap_value = $block_type->supports['spacing']['blockGap']['__experimentalDefault'] ?? '0.5em';
		$block_spacing      = $style_attr['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' );

		$block_gap             = $global_settings['spacing']['blockGap'] ?? null;
		$has_block_gap_support = isset( $block_gap );

		// Get default blockGap value from global styles for use in layouts like grid.
		// Check style variation first, then block-specific styles, then fall back to root styles.
		$block_name = $block['blockName'] ?? '';
		if ( null === $global_styles ) {
			$global_styles = wp_get_global_styles();
		}

		// Check if the block has an active style variation with a blockGap value.
		// Only check the registry if the className contains a variation class to avoid unnecessary lookups.
		$variation_block_gap_value = null;
		$block_class_name          = is_string( $block['attrs']['className'] ?? null )
			? $block['attrs']['className']
			: '';
		if ( $block_class_name && str_contains( $block_class_name, 'is-style-' ) && $block_name ) {
			$styles_registry   = WP_Block_Styles_Registry::get_instance();
			$registered_styles = $styles_registry->get_registered_styles_for_block( $block_name );
			$variation_name    = wp_get_block_style_variation_name_from_registered_style( $block_class_name, $registered_styles );
			if ( $variation_name ) {
				$variation_block_gap_value = $global_styles['blocks'][ $block_name ]['variations'][ $variation_name ]['spacing']['blockGap'] ?? null;
			}
		}

		$global_block_gap_value = $variation_block_gap_value ?? $global_styles['blocks'][ $block_name ]['spacing']['blockGap'] ?? $global_styles['spacing']['blockGap'] ?? null;

		if ( null !== $global_block_gap_value ) {
			$fallback_gap_value = $global_block_gap_value;
		}

		$container_class_hash_input = array(
			$used_layout,
			$has_block_gap_support,
			$gap_value,
			$should_skip_gap_serialization,
			$fallback_gap_value,
			$block_spacing,
		);

		foreach ( array_keys( $responsive_media_queries ) as $breakpoint ) {
			$viewport_style = $style_attr[ $breakpoint ] ?? null;
			if ( ! is_array( $viewport_style ) ) {
				continue;
			}

			$viewport_container_layout = wp_get_layout_container_values( $viewport_style['layout'] ?? null );
			if ( ! empty( $viewport_container_layout ) ) {
				$container_class_hash_input[] = array(
					'breakpoint' => $breakpoint,
					'layout'     => $viewport_container_layout,
				);
			}

			if ( isset( $viewport_style['spacing']['blockGap'] ) ) {
				$container_class_hash_input[] = array(
					'breakpoint' => $breakpoint,
					'blockGap'   => wp_sanitize_block_gap_value( $viewport_style['spacing']['blockGap'] ),
				);
			}
		}

		/*
		 * Generates a unique ID based on all the data required to obtain the
		 * corresponding layout style. Keeps the CSS class names the same
		 * even for different blocks on different places, as long as they have
		 * the same layout definition. Makes the CSS class names stable across
		 * paginations for features like the enhanced pagination of the Query block.
		 */
		$container_class = wp_unique_id_from_values(
			$container_class_hash_input,
			'wp-container-' . sanitize_title( $block['blockName'] ) . '-is-layout-'
		);

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

		/*
		 * Emit responsive container layout styles using the same $container_class
		 * selector as the base layout so they target the inner block wrapper.
		 */
		foreach ( $responsive_media_queries as $breakpoint => $media_query ) {
			$viewport_style = $style_attr[ $breakpoint ] ?? null;
			if ( ! is_array( $viewport_style ) ) {
				continue;
			}

			$viewport_container_layout = wp_get_layout_container_values( $viewport_style['layout'] ?? null );
			$has_viewport_layout       = ! empty( $viewport_container_layout );
			$has_viewport_block_gap    = isset( $viewport_style['spacing']['blockGap'] );

			if ( ! $has_viewport_layout && ! $has_viewport_block_gap ) {
				continue;
			}

			$viewport_gap_value = $has_viewport_block_gap
				? wp_sanitize_block_gap_value( $viewport_style['spacing']['blockGap'] )
				: $gap_value;

			$viewport_block_spacing = is_array( $viewport_style['spacing'] ?? null )
				? array_replace( is_array( $block_spacing ) ? $block_spacing : array(), $viewport_style['spacing'] )
				: $block_spacing;

			$viewport_styles = wp_get_layout_style(
				".$container_class",
				$used_layout,
				$has_block_gap_support,
				$viewport_gap_value,
				$should_skip_gap_serialization,
				$fallback_gap_value,
				$viewport_block_spacing,
				array(
					'rules_group'            => $media_query,
					'viewport_overrides'     => $viewport_container_layout,
					'has_block_gap_override' => $has_viewport_block_gap,
				)
			);

			if ( ! empty( $viewport_styles ) && ! in_array( $container_class, $class_names, true ) ) {
				$class_names[] = $container_class;
			}
		}

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

	// Add combined layout and block classname for global styles to hook onto.
	$split_block_name = explode( '/', $block['blockName'] );
	$full_block_name  = 'core' === $split_block_name[0] ? end( $split_block_name ) : implode( '-', $split_block_name );
	$class_names[]    = 'wp-block-' . $full_block_name . '-' . $layout_classname;

	// Add classes to the outermost HTML tag if necessary.
	if ( ! empty( $outer_class_names ) ) {
		foreach ( $outer_class_names as $outer_class_name ) {
			$processor->add_class( $outer_class_name );
		}
	}

	/**
	 * Attempts to refer to the inner-block wrapping element by its class attribute.
	 *
	 * When examining a block's inner content, if a block has inner blocks, then
	 * the first content item will likely be a text (HTML) chunk immediately
	 * preceding the inner blocks. The last HTML tag in that chunk would then be
	 * an opening tag for an element that wraps the inner blocks.
	 *
	 * There's no reliable way to associate this wrapper in $block_content because
	 * it may have changed during the rendering pipeline (as inner contents is
	 * provided before rendering) and through previous filters. In many cases,
	 * however, the `class` attribute will be a good-enough identifier, so this
	 * code finds the last tag in that chunk and stores the `class` attribute
	 * so that it can be used later when working through the rendered block output
	 * to identify the wrapping element and add the remaining class names to it.
	 *
	 * It's also possible that no inner block wrapper even exists. If that's the
	 * case this code could apply the class names to an invalid element.
	 *
	 * Example:
	 *
	 *     $block['innerBlocks']  = array( $list_item );
	 *     $block['innerContent'] = array( '<ul class="list-wrapper is-unordered">', null, '</ul>' );
	 *
	 *     // After rendering, the initial contents may have been modified by other renderers or filters.
	 *     $block_content = <<<HTML
	 *         <figure>
	 *             <ul class="annotated-list list-wrapper is-unordered">
	 *                 <li>Code</li>
	 *             </ul><figcaption>It's a list!</figcaption>
	 *         </figure>
	 *     HTML;
	 *
	 * Although it is possible that the original block-wrapper classes are changed in $block_content
	 * from how they appear in $block['innerContent'], it's likely that the original class attributes
	 * are still present in the wrapper as they are in this example. Frequently, additional classes
	 * will also be present; rarely should classes be removed.
	 *
	 * @todo Find a better way to match the first inner block. If it's possible to identify where the
	 *       first inner block starts, then it will be possible to find the last tag before it starts
	 *       and then that tag, if an opening tag, can be solidly identified as a wrapping element.
	 *       Can some unique value or class or ID be added to the inner blocks when they process
	 *       so that they can be extracted here safely without guessing? Can the block rendering function
	 *       return information about where the rendered inner blocks start?
	 *
	 * @var string|null
	 */
	$inner_block_wrapper_classes = null;
	$first_chunk                 = $block['innerContent'][0] ?? null;
	if ( is_string( $first_chunk ) && count( $block['innerContent'] ) > 1 ) {
		$first_chunk_processor = new WP_HTML_Tag_Processor( $first_chunk );
		/*
		 * Use a stack to track open elements as tags are visited. Void elements
		 * (those without a matching closing tag) are excluded so they don't
		 * accumulate on the stack. At the end of the chunk, every element still
		 * on the stack is unclosed — meaning its closing tag lives in a later
		 * innerContent entry alongside the inner blocks, which makes it the
		 * inner-block container. Elements that open and close within this chunk
		 * are siblings that precede the inner blocks and should be ignored.
		 * The last unclosed element with a class attribute is the best candidate
		 * for the inner-block wrapper.
		 */
		$tag_stack = array();
		while ( $first_chunk_processor->next_tag( array( 'tag_closers' => 'visit' ) ) ) {
			if ( $first_chunk_processor->is_tag_closer() ) {
				array_pop( $tag_stack );
			} elseif ( ! WP_HTML_Processor::is_void( $first_chunk_processor->get_tag() ) ) {
				$tag_stack[] = $first_chunk_processor->get_attribute( 'class' );
			}
		}
		foreach ( array_reverse( $tag_stack ) as $class_attribute ) {
			if ( is_string( $class_attribute ) && ! empty( $class_attribute ) ) {
				$inner_block_wrapper_classes = $class_attribute;
				break;
			}
		}
	}

	/*
	 * If necessary, advance to what is likely to be an inner block wrapper tag.
	 *
	 * This advances until it finds the first tag containing the original class
	 * attribute from above. If none is found it will scan to the end of the block
	 * and fail to add any class names.
	 *
	 * If there is no block wrapper it won't advance at all, in which case the
	 * class names will be added to the first and outermost tag of the block.
	 * For cases where this outermost tag is the only tag surrounding inner
	 * blocks then the outer wrapper and inner wrapper are the same.
	 */
	do {
		if ( ! $inner_block_wrapper_classes ) {
			break;
		}

		$class_attribute = $processor->get_attribute( 'class' );
		if ( is_string( $class_attribute ) && str_contains( $class_attribute, $inner_block_wrapper_classes ) ) {
			break;
		}
	} while ( $processor->next_tag() );

	// Add the remaining class names.
	foreach ( $class_names as $class_name ) {
		$processor->add_class( $class_name );
	}

	return $processor->get_updated_html();
}