features.module

<?php

/**
 * @file
 * Main hooks for Features module.
 */

use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function features_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.features':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The Features module provides a user interface for exporting bundles of configuration into modules. For more information, see the online documentation for <a href=":url">Features module</a>', [
        ':url' => 'http://drupal.org/node/2404427',
      ]) . '</p>';
      return $output;
  }
}

/**
 * Implements hook_file_download().
 */
function features_file_download($uri) {
  $stream_wrapper_manager = \Drupal::service('stream_wrapper_manager');
  $scheme = $stream_wrapper_manager->getScheme($uri);
  $target = $stream_wrapper_manager->getTarget($uri);

  if ($scheme == 'temporary' && $target) {
    $request = \Drupal::request();
    $route = $request->attributes->get('_route');
    // Check if we were called by Features download route.
    // No additional access checking needed here: route requires
    // "export configuration" permission, token is validated by the controller.
    // @see \Drupal\features\Controller\FeaturesController::downloadExport()
    if ($route == 'features.export_download') {
      return [
        'Content-disposition' => 'attachment; filename="' . $target . '"',
      ];
    }
  }
}

/**
 * Implements hook_modules_installed().
 */
function features_modules_installed($modules) {
  if (!in_array('features', $modules)) {
    /** @var \Drupal\features\FeaturesAssignerInterface $assigner */
    $assigner = \Drupal::service('features_assigner');
    $assigner->purgeConfiguration();
  }
}