Persistent Update API

The Persistent Update API module adds a hook (HOOK_persistent_update()) for persistent updates, updates that are run every time you access update.php or run 'drush updb'.

The module was created for use with a Features driven deployment model so that features would be reverted without human interaction, but can be used for other solutions.

Example

/**
 * Flush Drupal caches and revert feature components.
 */
function hook_persistent_update() {
  $module = basename(__FILE__, '.install');
  $info   = system_get_info('module', $module);

  // Enable all dependencies.
  module_enable($info['dependencies']);

  // Forcefully clear Features caches.
  module_load_include('inc', 'features', 'features.export');
  foreach (array_keys($info['features']) as $component) {
    if ($component == 'features_api') {
      continue;
    }

    features_get_components($component, NULL, TRUE);
    features_include_defaults($component, TRUE);
    features_get_default($component, $module, TRUE, TRUE);
  }

  // Build components list for feature revert.
  $revert[$module] = array_keys($info['features']);

  // Flush all standard Drupal caches.
  drupal_flush_all_caches();

  // Revert all feature component.
  features_revert($revert);
}