block.module

<?php


/**
 * @file
 */


/**
 * Assigns an initial, default set of blocks for a theme.
 *
 * This function is called the first time a new theme is installed. The new
 * theme gets a copy of the default theme's blocks, with the difference that if
 * a particular region isn't available in the new theme, the block is assigned
 * to the new theme's default region.
 *
 * @param string $theme
 *   The name of a theme.
 *
 * @deprecated in drupal:11.4.0 and is removed from drupal:13.0.0. No
 *   replacement is provided.
 *
 * @see https://www.drupal.org/node/3566783
 */
function block_theme_initialize($theme) : void {
  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:11.4.0 and is removed from drupal:13.0.0. No replacement is provided. See https://www.drupal.org/node/3566783', E_USER_DEPRECATED);
  // Initialize theme's blocks if none already registered.
  $has_blocks = \Drupal::entityTypeManager()->getStorage('block')
    ->loadByProperties([
    'theme' => $theme,
  ]);
  if (!$has_blocks) {
    $default_theme = \Drupal::config('system.theme')->get('default');
    // Apply only to new theme's visible regions.
    $regions = system_region_list($theme, REGIONS_VISIBLE);
    $default_theme_blocks = \Drupal::entityTypeManager()->getStorage('block')
      ->loadByProperties([
      'theme' => $default_theme,
    ]);
    foreach ($default_theme_blocks as $default_theme_block_id => $default_theme_block) {
      if (str_starts_with($default_theme_block_id, $default_theme . '_')) {
        $id = str_replace($default_theme . '_', '', $default_theme_block_id);
      }
      else {
        $id = $default_theme_block_id;
      }
      $id = \Drupal::service('block.repository')->getUniqueMachineName($id, $theme);
      $block = $default_theme_block->createDuplicateBlock($id, $theme);
      // If the region isn't supported by the theme, assign the block to the
      // theme's default region.
      if (!isset($regions[$block->getRegion()])) {
        $block->setRegion(system_default_region($theme));
      }
      $block->save();
    }
  }
}