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   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   * @param array $parsed_block The block being rendered.
  17   * @return array The migrated block object.
  18   */
  19  function block_core_gallery_data_id_backcompatibility( $parsed_block ) {
  20      if ( 'core/gallery' === $parsed_block['blockName'] ) {
  21          foreach ( $parsed_block['innerBlocks'] as $key => $inner_block ) {
  22              if ( 'core/image' === $inner_block['blockName'] ) {
  23                  if ( ! isset( $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] ) && isset( $inner_block['attrs']['id'] ) ) {
  24                      $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] = esc_attr( $inner_block['attrs']['id'] );
  25                  }
  26              }
  27          }
  28      }
  29  
  30      return $parsed_block;
  31  }
  32  
  33  add_filter( 'render_block_data', 'block_core_gallery_data_id_backcompatibility' );
  34  
  35  /**
  36   * Adds a style tag for the --wp--style--unstable-gallery-gap var.
  37   *
  38   * The Gallery block needs to recalculate Image block width based on
  39   * the current gap setting in order to maintain the number of flex columns
  40   * so a css var is added to allow this.
  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   */
  46  function block_core_gallery_render( $attributes, $content ) {
  47      $gap = _wp_array_get( $attributes, array( 'style', 'spacing', 'blockGap' ) );
  48      // Skip if gap value contains unsupported characters.
  49      // Regex for CSS value borrowed from `safecss_filter_attr`, and used here
  50      // because we only want to match against the value, not the CSS attribute.
  51      if ( is_array( $gap ) ) {
  52          foreach ( $gap as $key => $value ) {
  53              // Make sure $value is a string to avoid PHP 8.1 deprecation error in preg_match() when the value is null.
  54              $value = is_string( $value ) ? $value : '';
  55              $value = $value && preg_match( '%[\\\(&=}]|/\*%', $value ) ? null : $value;
  56  
  57              // Get spacing CSS variable from preset value if provided.
  58              if ( is_string( $value ) && str_contains( $value, 'var:preset|spacing|' ) ) {
  59                  $index_to_splice = strrpos( $value, '|' ) + 1;
  60                  $slug            = _wp_to_kebab_case( substr( $value, $index_to_splice ) );
  61                  $value           = "var(--wp--preset--spacing--$slug)";
  62              }
  63  
  64              $gap[ $key ] = $value;
  65          }
  66      } else {
  67          // Make sure $gap is a string to avoid PHP 8.1 deprecation error in preg_match() when the value is null.
  68          $gap = is_string( $gap ) ? $gap : '';
  69          $gap = $gap && preg_match( '%[\\\(&=}]|/\*%', $gap ) ? null : $gap;
  70  
  71          // Get spacing CSS variable from preset value if provided.
  72          if ( is_string( $gap ) && str_contains( $gap, 'var:preset|spacing|' ) ) {
  73              $index_to_splice = strrpos( $gap, '|' ) + 1;
  74              $slug            = _wp_to_kebab_case( substr( $gap, $index_to_splice ) );
  75              $gap             = "var(--wp--preset--spacing--$slug)";
  76          }
  77      }
  78  
  79      $unique_gallery_classname = wp_unique_id( 'wp-block-gallery-' );
  80      $processed_content        = new WP_HTML_Tag_Processor( $content );
  81      $processed_content->next_tag();
  82      $processed_content->add_class( $unique_gallery_classname );
  83  
  84      // --gallery-block--gutter-size is deprecated. --wp--style--gallery-gap-default should be used by themes that want to set a default
  85      // gap on the gallery.
  86      $fallback_gap = 'var( --wp--style--gallery-gap-default, var( --gallery-block--gutter-size, var( --wp--style--block-gap, 0.5em ) ) )';
  87      $gap_value    = $gap ? $gap : $fallback_gap;
  88      $gap_column   = $gap_value;
  89  
  90      if ( is_array( $gap_value ) ) {
  91          $gap_row    = isset( $gap_value['top'] ) ? $gap_value['top'] : $fallback_gap;
  92          $gap_column = isset( $gap_value['left'] ) ? $gap_value['left'] : $fallback_gap;
  93          $gap_value  = $gap_row === $gap_column ? $gap_row : $gap_row . ' ' . $gap_column;
  94      }
  95  
  96      // The unstable gallery gap calculation requires a real value (such as `0px`) and not `0`.
  97      if ( '0' === $gap_column ) {
  98          $gap_column = '0px';
  99      }
 100  
 101      // Set the CSS variable to the column value, and the `gap` property to the combined gap value.
 102      $gallery_styles = array(
 103          array(
 104              'selector'     => ".wp-block-gallery.{$unique_gallery_classname}",
 105              'declarations' => array(
 106                  '--wp--style--unstable-gallery-gap' => $gap_column,
 107                  'gap'                               => $gap_value,
 108              ),
 109          ),
 110      );
 111  
 112      wp_style_engine_get_stylesheet_from_css_rules(
 113          $gallery_styles,
 114          array(
 115              'context' => 'block-supports',
 116          )
 117      );
 118      return (string) $processed_content;
 119  }
 120  /**
 121   * Registers the `core/gallery` block on server.
 122   */
 123  function register_block_core_gallery() {
 124      register_block_type_from_metadata(
 125          __DIR__ . '/gallery',
 126          array(
 127              'render_callback' => 'block_core_gallery_render',
 128          )
 129      );
 130  }
 131  
 132  add_action( 'init', 'register_block_core_gallery' );