Returns cache ID parts for building a cache ID.
$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;
An array of cache ID parts, always containing the active theme. If the locale module is enabled it also contains the active language. If $granularity was passed in, more parts are added.
function drupal_render_cid_parts($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 (language_multilingual()) {
foreach (language_types_get_configurable() as $language_type) {
$cid_parts[] = language($language_type)->langcode;
}
}
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;
}