1<?php
2/**
3 * Background block support flag.
4 *
5 * @package WordPress
6 * @since 6.4.0
7 */
8
9/**
10 * Registers the style block attribute for block types that support it.
11 *
12 * @since 6.4.0
13 * @access private
14 *
15 * @param WP_Block_Type $block_type Block Type.
16 */
17function wp_register_background_support( $block_type ) {
18 // Setup attributes and styles within that if needed.
19 if ( ! $block_type->attributes ) {
20 $block_type->attributes = array();
21 }
22
23 // Check for existing style attribute definition e.g. from block.json.
24 if ( array_key_exists( 'style', $block_type->attributes ) ) {
25 return;
26 }
27
28 $has_background_support = block_has_support( $block_type, array( 'background' ), false );
29
30 if ( $has_background_support ) {
31 $block_type->attributes['style'] = array(
32 'type' => 'object',
33 );
34 }
35}
36
37/**
38 * Renders the background styles to the block wrapper.
39 * This block support uses the `render_block` hook to ensure that
40 * it is also applied to non-server-rendered blocks.
41 *
42 * @since 6.4.0
43 * @since 6.5.0 Added support for `backgroundPosition` and `backgroundRepeat` output.
44 * @since 6.6.0 Removed requirement for `backgroundImage.source`. A file/url is the default.
45 * @since 6.7.0 Added support for `backgroundAttachment` output.
46 *
47 * @access private
48 *
49 * @param string $block_content Rendered block content.
50 * @param array $block Block object.
51 * @return string Filtered block content.
52 */
53function wp_render_background_support( $block_content, $block ) {
54 $block_type = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
55 $block_attributes = ( isset( $block['attrs'] ) && is_array( $block['attrs'] ) ) ? $block['attrs'] : array();
56 $has_background_image_support = block_has_support( $block_type, array( 'background', 'backgroundImage' ), false );
57
58 if (
59 ! $has_background_image_support ||
60 wp_should_skip_block_supports_serialization( $block_type, 'background', 'backgroundImage' ) ||
61 ! isset( $block_attributes['style']['background'] )
62 ) {
63 return $block_content;
64 }
65
66 $background_styles = array();
67 $background_styles['backgroundImage'] = $block_attributes['style']['background']['backgroundImage'] ?? null;
68 $background_styles['backgroundSize'] = $block_attributes['style']['background']['backgroundSize'] ?? null;
69 $background_styles['backgroundPosition'] = $block_attributes['style']['background']['backgroundPosition'] ?? null;
70 $background_styles['backgroundRepeat'] = $block_attributes['style']['background']['backgroundRepeat'] ?? null;
71 $background_styles['backgroundAttachment'] = $block_attributes['style']['background']['backgroundAttachment'] ?? null;
72
73 if ( ! empty( $background_styles['backgroundImage'] ) ) {
74 $background_styles['backgroundSize'] = $background_styles['backgroundSize'] ?? 'cover';
75
76 // If the background size is set to `contain` and no position is set, set the position to `center`.
77 if ( 'contain' === $background_styles['backgroundSize'] && ! $background_styles['backgroundPosition'] ) {
78 $background_styles['backgroundPosition'] = '50% 50%';
79 }
80 }
81
82 $styles = wp_style_engine_get_styles( array( 'background' => $background_styles ) );
83
84 if ( ! empty( $styles['css'] ) ) {
85 // Inject background styles to the first element, presuming it's the wrapper, if it exists.
86 $tags = new WP_HTML_Tag_Processor( $block_content );
87
88 if ( $tags->next_tag() ) {
89 $existing_style = $tags->get_attribute( 'style' );
90 if ( is_string( $existing_style ) && '' !== $existing_style ) {
91 $separator = str_ends_with( $existing_style, ';' ) ? '' : ';';
92 $updated_style = "{$existing_style}{$separator}{$styles['css']}";
93 } else {
94 $updated_style = $styles['css'];
95 }
96
97 $tags->set_attribute( 'style', $updated_style );
98 $tags->add_class( 'has-background' );
99 }
100
101 return $tags->get_updated_html();
102 }
103
104 return $block_content;
105}
106
107// Register the block support.
108WP_Block_Supports::get_instance()->register(
109 'background',
110 array(
111 'register_attribute' => 'wp_register_background_support',
112 )
113);
114
115add_filter( 'render_block', 'wp_render_background_support', 10, 2 );
116