* Get the elements class names.

 *

 * @since 6.0.0

 * @access private

 *

 * @param array $block Block object.

 * @return string      The unique class name.

 */

function wp_get_elements_class_name( $block ) {

	return 'wp-elements-' . md5( serialize( $block ) );

}

/**

 * Update the block content with elements class names.

 * @param string $block_content Rendered block content.

 * @param array  $block         Block object.

 * @return string Filtered block content.

	if ( ! $block_content ) {

		return $block_content;

	}

	$block_type                    = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );

	$skip_link_color_serialization = wp_should_skip_block_supports_serialization( $block_type, 'color', 'link' );

	if ( $skip_link_color_serialization ) {

		return $block_content;

	}

	 * For now we only care about link color.

	 * This code in the future when we have a public API

	 * should take advantage of WP_Theme_JSON::compute_style_properties

	 * and work for any element and style.

	 */

	$class_name = wp_get_elements_class_name( $block );

	return $content;

}

/**

 * Render the elements stylesheet.

 *

 * In the case of nested blocks we want the parent element styles to be rendered before their descendants.

 * This solves the issue of an element (e.g.: link color) being styled in both the parent and a descendant:

 * we want the descendant style to take priority, and this is done by loading it after, in DOM order.

 *

 * @since 6.0.0

 * @access private

 *

 * @param string|null $pre_render   The pre-rendered content. Default null.

 * @param array       $block        The block being rendered.

 *

 * @return null

 */

function wp_render_elements_support_styles( $pre_render, $block ) {

	$block_type                    = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );

	$skip_link_color_serialization = wp_should_skip_block_supports_serialization( $block_type, 'color', 'link' );

	if ( $skip_link_color_serialization ) {

		return null;

	}

	$link_color = null;

	if ( ! empty( $block['attrs'] ) ) {

		$link_color = _wp_array_get( $block['attrs'], array( 'style', 'elements', 'link', 'color', 'text' ), null );

	}

	/*

	* For now we only care about link color.

	* This code in the future when we have a public API

	* should take advantage of WP_Theme_JSON::compute_style_properties

	* and work for any element and style.

	*/

	if ( null === $link_color ) {

		return null;

	}

	$class_name = wp_get_elements_class_name( $block );

	if ( strpos( $link_color, 'var:preset|color|' ) !== false ) {

		// Get the name from the string and add proper styles.

		$index_to_splice = strrpos( $link_color, '|' ) + 1;

		$link_color_name = substr( $link_color, $index_to_splice );

		$link_color      = "var(--wp--preset--color--$link_color_name)";

	}

	$link_color_declaration = esc_html( safecss_filter_attr( "color: $link_color" ) );

	$style = ".$class_name a{" . $link_color_declaration . ';}';

	wp_enqueue_block_support_styles( $style );

	return null;

add_filter( 'pre_render_block', 'wp_render_elements_support_styles', 10, 2 );