javascript - 需要帮助解决嵌套的 Promise，Promise 没有得到解决

Question

我设计了一个服务，它接受一些参数，然后循环输入数组，找出哪个项目是空的，然后将它们添加到数组中，然后在 $q.all 解析后，它应该给我空项目的数组.

输入是项目数组

function getElements(inputs) {
            var elements= [],
                promise, whenPromise,
                promises = [],
                mainPromise = $q.defer();
            if (inputs.length === 0) {
                mainPromise.resolve(elements);
                return mainPromise.promise;
            }

            angular.forEach(inputs, function (input) {
                promise = getPromises(input);
                whenPromise = $q.resolve(promise).then(function (response) {
                $timeout(function() {
                        if (response.isEmpty) {
                  **//perform action with the response.data;**
                        }
                  });
                }, function () {

                });

                promises.push(whenPromise);
            });


            $q.all(promises).finally(function () {
                 mainPromise.resolve(outdatedEntities);

            });

            return mainPromise.promise;
        }

        function getPromises(input) {
            var deferred = $q.defer();

            someSerivce.getItemDetails(input.Id).then(function (value) {
                if (value === null) {
                    $timeout(function () {
                        deferred.resolve({data: input, isEmpty: true});
                    });

                } else {
                    //have item locally, but need to see if it's current
                    input.isEmpty().then(function (isEmpty) {
                        $timeout(function () {
                            deferred.resolve({data: input, isEmpty: isEmpty});
                        });
                    }, function (error) {
                        deferred.reject(error);
                    });
                }

            });

            return deferred.promise;
        }

现在，问题是 $q.all 从未得到解决。尽管所有内部 promise 都得到了解决。

Answer 1

这应该有效:

function getElements(inputs) {
    var elements = [],
            promise, whenPromise,
            promises = [],
            mainPromise = $q.defer();
    if (inputs.length === 0) {
        mainPromise.resolve(elements);
        return mainPromise.promise;
    }

    angular.forEach(inputs, function (input) {
        promise = getPromises(input);
        whenPromise = promise.then(function (response) {

            if (response.isEmpty) {
                * *//perform action with the response.data;**
            }

        }, function () {

        });

        promises.push(whenPromise);
    });


    return $q.all(promises).finally(function () {
        return outdatedEntities;
    });
}

function getPromises(input) {
    return someSerivce.getItemDetails(input.Id).then(function (value) {
        if (value === null) {
            return {data: input, isEmpty: true};
        } else {
            //have item locally, but need to see if it's current
            return input.isEmpty().then(function (isEmpty) {
                return {data: input, isEmpty: isEmpty};
            }, function (error) {
                return error;
            });
        }
    });
}