/**
* Is the passed-in object different from this history item's?
* The object is compared to that previously set with {@link set_object()}. The objects must be the same. That
* is, their ids must match or the function throws an exception. This function is used to track differences between
* versions of an object, not to detect differences between objects.
* @param AUDITABLE $obj
* @access private
*/
public function record_differences($obj)
{
$objects_are_same_or_new = $obj->exists() == $this->_object->exists() && $obj->id == $this->_object->id;
$this->assert($objects_are_same_or_new, "Cannot compare two different objects (expected [{$this->_object->id}], got [{$obj->id}]", 'record_differences', 'HISTORY_ITEM');
if (!$obj->exists()) {
if (!isset($this->kind)) {
$this->kind = $obj->history_item_kind_for_new();
}
$this->_is_new = true;
} else {
if (!isset($this->kind)) {
$this->kind = History_item_updated;
}
$this->_record_differences($this->_object, $obj);
}
}
