Add custom CSS for block style variations.

backport-changelog/6.6/6797.md

@@ -0,0 +1,3 @@
+https://github.com/WordPress/wordpress-develop/pull/6797
+
+* https://github.com/WordPress/gutenberg/pull/62526

lib/class-wp-theme-json-gutenberg.php

@@ -2703,6 +2703,7 @@ public function get_styles_for_block( $block_metadata ) {
 
 		// If there are style variations, generate the declarations for them, including any feature selectors the block may have.
 		$style_variation_declarations = array();
+		$style_variation_custom_css   = array();
 		if ( ! empty( $block_metadata['variations'] ) ) {
 			foreach ( $block_metadata['variations'] as $style_variation ) {
 				$style_variation_node           = _wp_array_get( $this->theme_json, $style_variation['path'], array() );
@@ -2729,9 +2730,12 @@ static function ( $split_selector ) use ( $clean_style_variation_selector ) {
 					// Add the new declarations to the overall results under the modified selector.
 					$style_variation_declarations[ $combined_selectors ] = $new_declarations;
 				}
-
 				// Compute declarations for remaining styles not covered by feature level selectors.
 				$style_variation_declarations[ $style_variation['selector'] ] = static::compute_style_properties( $style_variation_node, $settings, null, $this->theme_json );
+				// Store custom CSS for the style variation.
+				if ( isset( $style_variation_node['css'] ) ) {
+					$style_variation_custom_css[ $style_variation['selector'] ] = $this->process_blocks_custom_css( $style_variation_node['css'], $style_variation['selector'] );
+				}
 			}
 		}
 
@@ -2862,6 +2866,9 @@ static function ( $pseudo_selector ) use ( $selector ) {
 		// 6. Generate and append the style variation rulesets.
 		foreach ( $style_variation_declarations as $style_variation_selector => $individual_style_variation_declarations ) {
 			$block_rules .= static::to_ruleset( ":root :where($style_variation_selector)", $individual_style_variation_declarations );
+			if ( isset( $style_variation_custom_css[ $style_variation_selector ] ) ) {
+				$block_rules .= $style_variation_custom_css[ $style_variation_selector ];
+			}
 		}
 
 		// 7. Generate and append any custom CSS rules.

packages/block-editor/src/components/global-styles/use-global-styles-output.js

@@ -651,7 +651,9 @@ export const getNodesWithStyles = ( tree, blockSelectors ) => {
 					( [ variationName, variation ] ) => {
 						variations[ variationName ] =
 							pickStyleKeys( variation );
-
+						if ( variation?.css ) {
+							variations[ variationName ].css = variation.css;
+						}
 						const variationSelector =
 							blockSelectors[ blockName ]
 								.styleVariationSelectors?.[ variationName ];
@@ -1041,6 +1043,12 @@ export const toStyles = (
 										';'
 									) };}`;
 								}
+								if ( styleVariations?.css ) {
+									ruleset += processCSSNesting(
+										styleVariations.css,
+										`:root :where(${ styleVariationSelector })`
+									);
+								}
 							}
 						}
 					);