BaseActiveRecord::afterSaveThruHasMany PHP Method

    private function afterSaveThruHasMany($name, $rel, $thru, $new_objs)
    {
        $thru_cls = $thru->className;
        // get the criteria from the named relation to apply to the through relation
        $criteria = new CDbCriteria();
        $criteria->addCondition($rel->on);
        $orig_objs = $this->getRelated($thru->name, true, $criteria);
        $orig_by_id = array();
        if ($orig_objs) {
            foreach ($orig_objs as $orig) {
                $orig_by_id[$orig->{$rel->foreignKey}] = $orig;
            }
        }
        if ($new_objs) {
            foreach ($new_objs as $i => $new) {
                if ($save = @$orig_by_id[$new->getPrimaryKey()]) {
                    unset($orig_by_id[$new->getPrimaryKey()]);
                } else {
                    $save = new $thru_cls();
                }
                $save->attributes = $this->getRelationsDefaults($name);
                $save->{$thru->foreignKey} = $this->getPrimaryKey();
                $save->{$rel->foreignKey} = $new->getPrimaryKey();
                if ($save->hasAttribute('display_order')) {
                    $save->display_order = $i + 1;
                }
                $a = $save->save();
                if (!$a) {
                    //save->save()) {
                    throw new Exception("unable to save new through relation {$thru->name} for {$name}" . print_r($save->getErrors(), true));
                }
            }
        }
        foreach ($orig_by_id as $orig) {
            if (!$orig->delete()) {
                throw new Exception("unable to delete redundant through relation {$thru->name} with id {$orig->getPrimaryKey()} for {$name}" . $orig->rel_id);
            }
        }
    }