Function then

src/js/WinJS/Promise/_StateMachine.js:678–683

(promise, onComplete, onError, onProgress)

        promise._setState(targetState);
    }
    function then(promise, onComplete, onError, onProgress) {
        var result = new ThenPromise(promise);
        var asyncOpID = _Trace._traceAsyncOperationStarting("WinJS.Promise.then");
        pushListener(promise, { promise: result, c: onComplete, e: onError, p: onProgress, asyncOpID: asyncOpID });
        return result;
    }

    //
    // Internal implementation detail promise, ThenPromise is created when a promise needs