function ThemeInstaller::getThemesToInstall

File

core/lib/Drupal/Core/Extension/ThemeInstaller.php, line 55

Class

ThemeInstaller

Manages theme installation/uninstallation.

Namespace

Code

public function getThemesToInstall(array $theme_list, bool $install_dependencies = TRUE) : array {
  if (!$install_dependencies) {
    // Without dependency resolution the caller is responsible for providing a
    // complete list; the install loop still skips already-installed themes.
    return array_values($theme_list);
  }
  $extension_config = $this->configFactory
    ->get('core.extension');
  $theme_data = $this->themeExtensionList
    ->reset()
    ->getList();
  $installed_themes = $extension_config->get('theme') ?: [];
  $installed_modules = $extension_config->get('module') ?: [];
  $theme_list = array_combine(array_values($theme_list), array_values($theme_list));
  if ($missing = array_diff_key($theme_list, $theme_data)) {
    // One or more of the given themes doesn't exist.
    throw new UnknownExtensionException('Unknown themes: ' . implode(', ', $missing) . '.');
  }
  // Only process themes that are not installed currently.
  if (!$theme_list = array_diff_key($theme_list, $installed_themes)) {
    // Nothing to do. All themes already installed.
    return [];
  }
  $module_list = $this->moduleExtensionList
    ->getList();
  foreach ($theme_list as $theme => $value) {
    $module_dependencies = $theme_data[$theme]->module_dependencies;
    // $theme_data[$theme]->requires contains both theme and module
    // dependencies keyed by the extension machine names.
    // $theme_data[$theme]->module_dependencies contains only the module
    // dependencies keyed by the module extension machine name. Therefore,
    // we can find the theme dependencies by finding array keys for
    // 'requires' that are not in $module_dependencies.
    $theme_dependencies = array_diff_key($theme_data[$theme]->requires, $module_dependencies);
    // We can find the unmet module dependencies by finding the module
    // machine names keys that are not in $installed_modules keys.
    $unmet_module_dependencies = array_diff_key($module_dependencies, $installed_modules);
    // Prevent themes with unmet module dependencies from being installed.
    if (!empty($unmet_module_dependencies)) {
      $unmet_module_dependencies_list = implode(', ', array_keys($unmet_module_dependencies));
      throw new MissingDependencyException("Unable to install theme: '{$theme}' due to unmet module dependencies: '{$unmet_module_dependencies_list}'.");
    }
    foreach ($module_dependencies as $dependency => $dependency_object) {
      if ($incompatible = $this->checkDependencyMessage($module_list, $dependency, $dependency_object)) {
        $sanitized_message = Html::decodeEntities(strip_tags($incompatible));
        throw new MissingDependencyException("Unable to install theme: {$sanitized_message}");
      }
    }
    // Add dependencies to the list of themes to install. The new themes
    // will be processed as the parent foreach loop continues.
    foreach (array_keys($theme_dependencies) as $dependency) {
      if (!isset($theme_data[$dependency])) {
        // The dependency does not exist.
        throw new UnknownExtensionException("Unable to install theme: '{$theme}' is missing its theme dependency '{$dependency}'.");
      }
      // Skip already installed themes.
      if (!isset($theme_list[$dependency]) && !isset($installed_themes[$dependency])) {
        $theme_list[$dependency] = $dependency;
      }
    }
  }
  // Set the actual theme weights.
  $theme_list = array_map(function ($theme) use ($theme_data) {
    return $theme_data[$theme]->sort;
  }, $theme_list);
  // Sort the theme list by their weights (reverse).
  arsort($theme_list);
  return array_keys($theme_list);
}