datasift / storyplayer

        }

        // make sure we have our details

        if (!isset($tables->$tableName->$key)) {

            $msg = "table does not contain item '{$key}'";

            $log->endAction($msg);

            throw Exceptions::newExpectFailedException(__METHOD__, "{$tableName} table has item '{$key}'", "{$tableName} table has no item '{$key}'");

        }

        // all done

        $log->endAction();

        }

        // make sure we don't have the details

        if (isset($tables->$tableName->$key)) {

            $msg = "table already contains no item '{$key}'";

            $log->endAction($msg);

            throw Exceptions::newExpectFailedException(__METHOD__, "{$tableName} table has no item '{$key}'", "{$tableName} table has item '{$key}'");

        }

        // all done

        $log->endAction();

        }

        // make sure we don't have a duplicate entry

        if (isset($tables->$tableName->$group->$key)){

            $msg = "table already contains an entry for '{$group}->{$key}'";

            $log->endAction($msg);

            throw Exceptions::newActionFailedException(__METHOD__, $msg);

        }

        // add the entry

        $tables->$tableName->$group->$key = $value;