Implements hook_field_formatter_prepare_view().
This preloads all taxonomy terms for multiple loaded objects at once and unsets values for invalid terms that do not exist.
function taxonomy_field_formatter_prepare_view($entity_type, $entities, $field, $instances, $langcode, &$items, $displays) {
$tids = array();
// Collect every possible term attached to any of the fieldable entities.
foreach ($entities as $id => $entity) {
foreach ($items[$id] as $delta => $item) {
// Force the array key to prevent duplicates.
if ($item['tid'] != 'autocreate') {
$tids[$item['tid']] = $item['tid'];
}
}
}
if ($tids) {
$terms = taxonomy_term_load_multiple($tids);
// Iterate through the fieldable entities again to attach the loaded term data.
foreach ($entities as $id => $entity) {
$rekey = FALSE;
foreach ($items[$id] as $delta => $item) {
// Check whether the taxonomy term field instance value could be loaded.
if (isset($terms[$item['tid']])) {
// Replace the instance value with the term data.
$items[$id][$delta]['taxonomy_term'] = $terms[$item['tid']];
}
elseif ($item['tid'] == 'autocreate') {
// Leave the item in place.
}
else {
unset($items[$id][$delta]);
$rekey = TRUE;
}
}
if ($rekey) {
// Rekey the items array.
$items[$id] = array_values($items[$id]);
}
}
}
}