Returns cache ID parts for building a cache ID.

Parameters

$granularity: One or more cache granularity constants. For example, to cache separately for each user, use DRUPAL_CACHE_PER_USER. To cache separately for each page and role, use the expression:

  DRUPAL_CACHE_PER_PAGE | DRUPAL_CACHE_PER_ROLE
  

Return value

An array of cache ID parts, always containing the active theme. If the locale module is enabled it also contains the active language. If $granularity was passed in, more parts are added.

File

drupal-7.x/includes/common.inc, line 6224

Common functions that many Drupal modules will need to reference.

Code

function drupal_render_cid_parts($granularity = NULL) {
  global $theme, $base_root, $user;

  $cid_parts[] = $theme;
  // If Locale is enabled but we have only one language we do not need it as cid
  // part.
  if (drupal_multilingual()) {
    foreach (language_types_configurable() as $language_type) {
      $cid_parts[] = $GLOBALS[$language_type]->language;
    }
  }

  if (!empty($granularity)) {
    // 'PER_ROLE' and 'PER_USER' are mutually exclusive. 'PER_USER' can be a
    // resource drag for sites with many users, so when a module is being
    // equivocal, we favor the less expensive 'PER_ROLE' pattern.
    if ($granularity & DRUPAL_CACHE_PER_ROLE) {
      $cid_parts[] = 'r.' . implode(',', array_keys($user->roles));
    }
    elseif ($granularity & DRUPAL_CACHE_PER_USER) {
      $cid_parts[] = "u.$user->uid";
    }

    if ($granularity & DRUPAL_CACHE_PER_PAGE) {
      $cid_parts[] = $base_root . request_uri();
    }
  }

  return $cid_parts;
}