1<?php
2/**
3 * Server-side rendering of the `core/gallery` block.
4 *
5 * @package WordPress
6 */
7
8/**
9 * Handles backwards compatibility for Gallery Blocks,
10 * whose images feature a `data-id` attribute.
11 *
12 * Now that the Gallery Block contains inner Image Blocks,
13 * we add a custom `data-id` attribute before rendering the gallery
14 * so that the Image Block can pick it up in its render_callback.
15 *
16 * @since 5.9.0
17 *
18 * @param array $parsed_block The block being rendered.
19 * @return array The migrated block object.
20 */
21function block_core_gallery_data_id_backcompatibility( $parsed_block ) {
22 if ( 'core/gallery' === $parsed_block['blockName'] ) {
23 foreach ( $parsed_block['innerBlocks'] as $key => $inner_block ) {
24 if ( 'core/image' === $inner_block['blockName'] ) {
25 if ( ! isset( $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] ) && isset( $inner_block['attrs']['id'] ) ) {
26 $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] = esc_attr( $inner_block['attrs']['id'] );
27 }
28 }
29 }
30 }
31
32 return $parsed_block;
33}
34
35add_filter( 'render_block_data', 'block_core_gallery_data_id_backcompatibility' );
36
37/**
38 * Renders the `core/gallery` block on the server.
39 *
40 * @since 6.0.0
41 *
42 * @param array $attributes Attributes of the block being rendered.
43 * @param string $content Content of the block being rendered.
44 * @return string The content of the block being rendered.
45 */
46function block_core_gallery_render( $attributes, $content ) {
47 // Adds a style tag for the --wp--style--unstable-gallery-gap var.
48 // The Gallery block needs to recalculate Image block width based on
49 // the current gap setting in order to maintain the number of flex columns
50 // so a css var is added to allow this.
51
52 $gap = $attributes['style']['spacing']['blockGap'] ?? null;
53 // Skip if gap value contains unsupported characters.
54 // Regex for CSS value borrowed from `safecss_filter_attr`, and used here
55 // because we only want to match against the value, not the CSS attribute.
56 if ( is_array( $gap ) ) {
57 foreach ( $gap as $key => $value ) {
58 // Make sure $value is a string to avoid PHP 8.1 deprecation error in preg_match() when the value is null.
59 $value = is_string( $value ) ? $value : '';
60 $value = $value && preg_match( '%[\\\(&=}]|/\*%', $value ) ? null : $value;
61
62 // Get spacing CSS variable from preset value if provided.
63 if ( is_string( $value ) && str_contains( $value, 'var:preset|spacing|' ) ) {
64 $index_to_splice = strrpos( $value, '|' ) + 1;
65 $slug = _wp_to_kebab_case( substr( $value, $index_to_splice ) );
66 $value = "var(--wp--preset--spacing--$slug)";
67 }
68
69 $gap[ $key ] = $value;
70 }
71 } else {
72 // Make sure $gap is a string to avoid PHP 8.1 deprecation error in preg_match() when the value is null.
73 $gap = is_string( $gap ) ? $gap : '';
74 $gap = $gap && preg_match( '%[\\\(&=}]|/\*%', $gap ) ? null : $gap;
75
76 // Get spacing CSS variable from preset value if provided.
77 if ( is_string( $gap ) && str_contains( $gap, 'var:preset|spacing|' ) ) {
78 $index_to_splice = strrpos( $gap, '|' ) + 1;
79 $slug = _wp_to_kebab_case( substr( $gap, $index_to_splice ) );
80 $gap = "var(--wp--preset--spacing--$slug)";
81 }
82 }
83
84 $unique_gallery_classname = wp_unique_id( 'wp-block-gallery-' );
85 $processed_content = new WP_HTML_Tag_Processor( $content );
86 $processed_content->next_tag();
87 $processed_content->add_class( $unique_gallery_classname );
88
89 // --gallery-block--gutter-size is deprecated. --wp--style--gallery-gap-default should be used by themes that want to set a default
90 // gap on the gallery.
91 $fallback_gap = 'var( --wp--style--gallery-gap-default, var( --gallery-block--gutter-size, var( --wp--style--block-gap, 0.5em ) ) )';
92 $gap_value = $gap ? $gap : $fallback_gap;
93 $gap_column = $gap_value;
94
95 if ( is_array( $gap_value ) ) {
96 $gap_row = isset( $gap_value['top'] ) ? $gap_value['top'] : $fallback_gap;
97 $gap_column = isset( $gap_value['left'] ) ? $gap_value['left'] : $fallback_gap;
98 $gap_value = $gap_row === $gap_column ? $gap_row : $gap_row . ' ' . $gap_column;
99 }
100
101 // The unstable gallery gap calculation requires a real value (such as `0px`) and not `0`.
102 if ( '0' === $gap_column ) {
103 $gap_column = '0px';
104 }
105
106 // Set the CSS variable to the column value, and the `gap` property to the combined gap value.
107 $gallery_styles = array(
108 array(
109 'selector' => ".wp-block-gallery.{$unique_gallery_classname}",
110 'declarations' => array(
111 '--wp--style--unstable-gallery-gap' => $gap_column,
112 'gap' => $gap_value,
113 ),
114 ),
115 );
116
117 wp_style_engine_get_stylesheet_from_css_rules(
118 $gallery_styles,
119 array(
120 'context' => 'block-supports',
121 )
122 );
123
124 // The WP_HTML_Tag_Processor class calls get_updated_html() internally
125 // when the instance is treated as a string, but here we explicitly
126 // convert it to a string.
127 $updated_content = $processed_content->get_updated_html();
128
129 /*
130 * Randomize the order of image blocks. Ideally we should shuffle
131 * the `$parsed_block['innerBlocks']` via the `render_block_data` hook.
132 * However, this hook doesn't apply inner block updates when blocks are
133 * nested.
134 * @todo In the future, if this hook supports updating innerBlocks in
135 * nested blocks, it should be refactored.
136 *
137 * @see: https://github.com/WordPress/gutenberg/pull/58733
138 */
139 if ( empty( $attributes['randomOrder'] ) ) {
140 return $updated_content;
141 }
142
143 // This pattern matches figure elements with the `wp-block-image` class to
144 // avoid the gallery's wrapping `figure` element and extract images only.
145 $pattern = '/<figure[^>]*\bwp-block-image\b[^>]*>.*?<\/figure>/s';
146
147 // Find all Image blocks.
148 preg_match_all( $pattern, $updated_content, $matches );
149 if ( ! $matches ) {
150 return $updated_content;
151 }
152 $image_blocks = $matches[0];
153
154 // Randomize the order of Image blocks.
155 shuffle( $image_blocks );
156 $i = 0;
157 $content = preg_replace_callback(
158 $pattern,
159 static function () use ( $image_blocks, &$i ) {
160 $new_image_block = $image_blocks[ $i ];
161 ++$i;
162 return $new_image_block;
163 },
164 $updated_content
165 );
166
167 return $content;
168}
169/**
170 * Registers the `core/gallery` block on server.
171 *
172 * @since 5.9.0
173 */
174function register_block_core_gallery() {
175 register_block_type_from_metadata(
176 __DIR__ . '/gallery',
177 array(
178 'render_callback' => 'block_core_gallery_render',
179 )
180 );
181}
182
183add_action( 'init', 'register_block_core_gallery' );
184