WP_Theme_JSON::get_block_style_variation_selector( string $variation_name, string $block_selector ): string

5866	protected static function get_block_style_variation_selector( $variation_name, $block_selector ) {5867		$variation_class = ".is-style-$variation_name";5868 5869		if ( ! $block_selector ) {5870			return $variation_class;5871		}5872 5873		$limit          = 1;5874		$selector_parts = static::split_selector_list( $block_selector );5875		$result         = array();5876 5877		/*5878		 * Append the variation class to each selector's ancestor: the first5879		 * run of characters before any combinator (whitespace) or pseudo-class5880		 * (`:`). Only the first match is replaced.5881		 *5882		 * Examples ("custom" variation):5883		 * - `.wp-block`              => `.wp-block.is-style-custom`5884		 * - `.wp-block .inner`       => `.wp-block.is-style-custom .inner`5885		 * - `.wp-block:where(.a .b)` => `.wp-block.is-style-custom:where(.a .b)`5886		 * - `:where(.outer .inner)`  => `:where(.outer.is-style-custom .inner)`5887		 */5888		foreach ( $selector_parts as $part ) {5889			$result[] = preg_replace_callback(5890				'/[^\s:]+/',5891				function ( $matches ) use ( $variation_class ) {5892					return $matches[0] . $variation_class;5893				},5894				$part,5895				$limit5896			);5897		}5898 5899		return implode( ', ', $result );5900	}