/**
* {@inheritdoc}
*/
public function loadMultiple(array $ids = NULL)
{
$entities = array();
// Create a new variable which is either a prepared version of the $ids
// array for later comparison with the entity cache, or FALSE if no $ids
// were passed. The $ids array is reduced as items are loaded from cache,
// and we need to know if it's empty for this reason to avoid querying the
// database when all requested entities are loaded from cache.
$passed_ids = !empty($ids) ? array_flip($ids) : FALSE;
// Try to load entities from the static cache, if the entity type supports
// static caching.
if ($this->entityType->isStaticallyCacheable() && $ids) {
$entities += $this->getFromStaticCache($ids);
// If any entities were loaded, remove them from the ids still to load.
if ($passed_ids) {
$ids = array_keys(array_diff_key($passed_ids, $entities));
}
}
// Load any remaining entities from the database. This is the case if $ids
// is set to NULL (so we load all entities) or if there are any ids left to
// load.
if ($ids === NULL || $ids) {
$queried_entities = $this->doLoadMultiple($ids);
}
// Pass all entities loaded from the database through $this->postLoad(),
// which attaches fields (if supported by the entity type) and calls the
// entity type specific load callback, for example hook_node_load().
if (!empty($queried_entities)) {
$this->postLoad($queried_entities);
$entities += $queried_entities;
}
if ($this->entityType->isStaticallyCacheable()) {
// Add entities to the cache.
if (!empty($queried_entities)) {
$this->setStaticCache($queried_entities);
}
}
// Ensure that the returned array is ordered the same as the original
// $ids array if this was passed in and remove any invalid ids.
if ($passed_ids) {
// Remove any invalid ids from the array.
$passed_ids = array_intersect_key($passed_ids, $entities);
foreach ($entities as $entity) {
$passed_ids[$entity->id()] = $entity;
}
$entities = $passed_ids;
}
return $entities;
}
