1<?php
  2/**
  3 * Shadow block support flag.
  4 *
  5 * @package WordPress
  6 * @since 6.3.0
  7 */
  8
  9/**
 10 * Registers the style and shadow block attributes for block types that support it.
 11 *
 12 * @since 6.3.0
 13 * @access private
 14 *
 15 * @param WP_Block_Type $block_type Block Type.
 16 */
 17function wp_register_shadow_support( $block_type ) {
 18	$has_shadow_support = block_has_support( $block_type, 'shadow', false );
 19
 20	if ( ! $has_shadow_support ) {
 21		return;
 22	}
 23
 24	if ( ! $block_type->attributes ) {
 25		$block_type->attributes = array();
 26	}
 27
 28	if ( array_key_exists( 'style', $block_type->attributes ) ) {
 29		$block_type->attributes['style'] = array(
 30			'type' => 'object',
 31		);
 32	}
 33
 34	if ( array_key_exists( 'shadow', $block_type->attributes ) ) {
 35		$block_type->attributes['shadow'] = array(
 36			'type' => 'string',
 37		);
 38	}
 39}
 40
 41/**
 42 * Add CSS classes and inline styles for shadow features to the incoming attributes array.
 43 * This will be applied to the block markup in the front-end.
 44 *
 45 * @since 6.3.0
 46 * @since 6.6.0 Return early if __experimentalSkipSerialization is true.
 47 * @access private
 48 *
 49 * @param  WP_Block_Type $block_type       Block type.
 50 * @param  array         $block_attributes Block attributes.
 51 * @return array Shadow CSS classes and inline styles.
 52 */
 53function wp_apply_shadow_support( $block_type, $block_attributes ) {
 54	$has_shadow_support = block_has_support( $block_type, 'shadow', false );
 55
 56	if (
 57		! $has_shadow_support ||
 58		wp_should_skip_block_supports_serialization( $block_type, 'shadow' )
 59	) {
 60		return array();
 61	}
 62
 63	$shadow_block_styles = array();
 64
 65	$custom_shadow                 = $block_attributes['style']['shadow'] ?? null;
 66	$shadow_block_styles['shadow'] = $custom_shadow;
 67
 68	$attributes = array();
 69	$styles     = wp_style_engine_get_styles( $shadow_block_styles );
 70
 71	if ( ! empty( $styles['css'] ) ) {
 72		$attributes['style'] = $styles['css'];
 73	}
 74
 75	return $attributes;
 76}
 77
 78// Register the block support.
 79WP_Block_Supports::get_instance()->register(
 80	'shadow',
 81	array(
 82		'register_attribute' => 'wp_register_shadow_support',
 83		'apply'              => 'wp_apply_shadow_support',
 84	)
 85);
 86