public static function builder_call_nested_collection(Database_Query_Builder $builder, Jam_Event_Data $data, $groups = FALSE, $depth = 0)
{
$choices = array();
if ($depth == 0) {
$builder->root();
}
$items = $builder->order_by(':name_key', 'ASC');
foreach ($items as $item) {
if ($groups and $depth == 0) {
$choices[$item->name()] = array();
if ($item->children->count()) {
$choices[$item->name()] = self::builder_call_nested_collection($item->children->collection(), $data, $groups, $depth + 1);
}
} else {
$choices[$item->id()] = str_repeat(' ', $depth) . $item->name();
if ($item->children->count()) {
$choices = Arr::merge($choices, self::builder_call_nested_collection($item->children->collection(), $data, $groups, $depth + 1));
}
}
}
if ($depth == 0) {
$data->return = $choices;
} else {
return $choices;
}
}
