<?php 
/** 
 * Server-side rendering of the `core/gallery` block. 
 * 
 * @package WordPress 
 */ 
 
/** 
 * Handles backwards compatibility for Gallery Blocks, 
 * whose images feature a `data-id` attribute. 
 * 
 * Now that the Gallery Block contains inner Image Blocks, 
 * we add a custom `data-id` attribute before rendering the gallery 
 * so that the Image Block can pick it up in its render_callback. 
 * 
 * @since 5.9.0 
 * 
 * @param array $parsed_block The block being rendered. 
 * @return array The migrated block object. 
 */ 
function block_core_gallery_data_id_backcompatibility( $parsed_block ) { 
    if ( 'core/gallery' === $parsed_block['blockName'] ) { 
        foreach ( $parsed_block['innerBlocks'] as $key => $inner_block ) { 
            if ( 'core/image' === $inner_block['blockName'] ) { 
                if ( ! isset( $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] ) && isset( $inner_block['attrs']['id'] ) ) { 
                    $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] = esc_attr( $inner_block['attrs']['id'] ); 
                } 
            } 
        } 
    } 
 
    return $parsed_block; 
} 
 
add_filter( 'render_block_data', 'block_core_gallery_data_id_backcompatibility' ); 
 
/** 
 * Renders the `core/gallery` block on the server. 
 * 
 * @since 6.0.0 
 * 
 * @param array  $attributes Attributes of the block being rendered. 
 * @param string $content Content of the block being rendered. 
 * @return string The content of the block being rendered. 
 */ 
function block_core_gallery_render( $attributes, $content ) { 
    // Adds a style tag for the --wp--style--unstable-gallery-gap var. 
    // The Gallery block needs to recalculate Image block width based on 
    // the current gap setting in order to maintain the number of flex columns 
    // so a css var is added to allow this. 
 
    $gap = $attributes['style']['spacing']['blockGap'] ?? null; 
    // Skip if gap value contains unsupported characters. 
    // Regex for CSS value borrowed from `safecss_filter_attr`, and used here 
    // because we only want to match against the value, not the CSS attribute. 
    if ( is_array( $gap ) ) { 
        foreach ( $gap as $key => $value ) { 
            // Make sure $value is a string to avoid PHP 8.1 deprecation error in preg_match() when the value is null. 
            $value = is_string( $value ) ? $value : ''; 
            $value = $value && preg_match( '%[\\\(&=}]|/\*%', $value ) ? null : $value; 
 
            // Get spacing CSS variable from preset value if provided. 
            if ( is_string( $value ) && str_contains( $value, 'var:preset|spacing|' ) ) { 
                $index_to_splice = strrpos( $value, '|' ) + 1; 
                $slug            = _wp_to_kebab_case( substr( $value, $index_to_splice ) ); 
                $value           = "var(--wp--preset--spacing--$slug)"; 
            } 
 
            $gap[ $key ] = $value; 
        } 
    } else { 
        // Make sure $gap is a string to avoid PHP 8.1 deprecation error in preg_match() when the value is null. 
        $gap = is_string( $gap ) ? $gap : ''; 
        $gap = $gap && preg_match( '%[\\\(&=}]|/\*%', $gap ) ? null : $gap; 
 
        // Get spacing CSS variable from preset value if provided. 
        if ( is_string( $gap ) && str_contains( $gap, 'var:preset|spacing|' ) ) { 
            $index_to_splice = strrpos( $gap, '|' ) + 1; 
            $slug            = _wp_to_kebab_case( substr( $gap, $index_to_splice ) ); 
            $gap             = "var(--wp--preset--spacing--$slug)"; 
        } 
    } 
 
    $unique_gallery_classname = wp_unique_id( 'wp-block-gallery-' ); 
    $processed_content        = new WP_HTML_Tag_Processor( $content ); 
    $processed_content->next_tag(); 
    $processed_content->add_class( $unique_gallery_classname ); 
 
    // --gallery-block--gutter-size is deprecated. --wp--style--gallery-gap-default should be used by themes that want to set a default 
    // gap on the gallery. 
    $fallback_gap = 'var( --wp--style--gallery-gap-default, var( --gallery-block--gutter-size, var( --wp--style--block-gap, 0.5em ) ) )'; 
    $gap_value    = $gap ? $gap : $fallback_gap; 
    $gap_column   = $gap_value; 
 
    if ( is_array( $gap_value ) ) { 
        $gap_row    = isset( $gap_value['top'] ) ? $gap_value['top'] : $fallback_gap; 
        $gap_column = isset( $gap_value['left'] ) ? $gap_value['left'] : $fallback_gap; 
        $gap_value  = $gap_row === $gap_column ? $gap_row : $gap_row . ' ' . $gap_column; 
    } 
 
    // The unstable gallery gap calculation requires a real value (such as `0px`) and not `0`. 
    if ( '0' === $gap_column ) { 
        $gap_column = '0px'; 
    } 
 
    // Set the CSS variable to the column value, and the `gap` property to the combined gap value. 
    $gallery_styles = array( 
        array( 
            'selector'     => ".wp-block-gallery.{$unique_gallery_classname}", 
            'declarations' => array( 
                '--wp--style--unstable-gallery-gap' => $gap_column, 
                'gap'                               => $gap_value, 
            ), 
        ), 
    ); 
 
    wp_style_engine_get_stylesheet_from_css_rules( 
        $gallery_styles, 
        array( 
            'context' => 'block-supports', 
        ) 
    ); 
 
    // The WP_HTML_Tag_Processor class calls get_updated_html() internally 
    // when the instance is treated as a string, but here we explicitly 
    // convert it to a string. 
    $updated_content = $processed_content->get_updated_html(); 
 
    /* 
     * Randomize the order of image blocks. Ideally we should shuffle 
     * the `$parsed_block['innerBlocks']` via the `render_block_data` hook. 
     * However, this hook doesn't apply inner block updates when blocks are 
     * nested. 
     * @todo In the future, if this hook supports updating innerBlocks in 
     * nested blocks, it should be refactored. 
     * 
     * @see: https://github.com/WordPress/gutenberg/pull/58733 
     */ 
    if ( empty( $attributes['randomOrder'] ) ) { 
        return $updated_content; 
    } 
 
    // This pattern matches figure elements with the `wp-block-image` class to 
    // avoid the gallery's wrapping `figure` element and extract images only. 
    $pattern = '/<figure[^>]*\bwp-block-image\b[^>]*>.*?<\/figure>/'; 
 
    // Find all Image blocks. 
    preg_match_all( $pattern, $updated_content, $matches ); 
    if ( ! $matches ) { 
        return $updated_content; 
    } 
    $image_blocks = $matches[0]; 
 
    // Randomize the order of Image blocks. 
    shuffle( $image_blocks ); 
    $i       = 0; 
    $content = preg_replace_callback( 
        $pattern, 
        static function () use ( $image_blocks, &$i ) { 
            $new_image_block = $image_blocks[ $i ]; 
            ++$i; 
            return $new_image_block; 
        }, 
        $updated_content 
    ); 
 
    return $content; 
} 
/** 
 * Registers the `core/gallery` block on server. 
 * 
 * @since 5.9.0 
 */ 
function register_block_core_gallery() { 
    register_block_type_from_metadata( 
        __DIR__ . '/gallery', 
        array( 
            'render_callback' => 'block_core_gallery_render', 
        ) 
    ); 
} 
 
add_action( 'init', 'register_block_core_gallery' ); 
 
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