本地缓存不是从Angular中的服务调用更新的

Question

我被深深地抛弃而不确定我在看什么，但是我真的想了解为什么下面代码中的本地缓存没有被更新。

这是我的控制者：

    scope.assessment = assessment;
    assessment.possibleScore = 0;
    assessment.score = 0;

    assessment.test.items.forEach(function (item) {
        assessment.possibleScore += item.possibleScore;
        assessment.score += item.mark;
    });

    scope.percentageScore = Math.floor(assessment.score / assessment.possibleScore * 100);

    AssessmentService.updateUserAssessment(assessment);

这是在AssessmentService中调用的updateUserAssessment函数：

    /**
     * Given a userAssessment object, update the cache and server.
     * @param userAssessment - The object we want updating
     * @returns a promise which resolves to the updated user assessment, if successful.
     */
    self.updateUserAssessment = function (userAssessment) {
        delete userAssessment.$resolved;
        delete userAssessment.$promise;
        if (self.assessmentCache[userAssessment._id]) {
            _.assign(self.assessmentCache[userAssessment._id], userAssessment);
        } else {
            self.assessmentCache[userAssessment._id] = userAssessment;
            self.assessmentCache[userAssessment._id].dirty = true;
        }

        var items = self.assessmentCache[userAssessment._id].test.items;

        return UserAssessment
            .nestedUpdateById({
                userId: userAssessment.user,
                assessmentId: userAssessment._id
            }, self.assessmentCache[userAssessment._id])
            .$promise
            .then(function (assessment) {
                _.assign(self.assessmentCache[userAssessment._id], assessment);
                self.assessmentCache[userAssessment._id].dirty = false;
                self.assessmentCache[userAssessment._id].test.items = items;
                self.saveCache();
                return self.assessmentCache[userAssessment._id];
            });
    };

上面的函数应该更新服务器以及localcache，但似乎没有这样做。

作为一个FYI，这就是self.assessmentCache持有者：

    self.loadAssessmentCache = function () {
        var cachedAssessments = window.localStorage.getItem('assessments');
        self.assessmentCache = cachedAssessments ? JSON.parse(cachedAssessments) : {};
    };

**更新***

    self.saveCache = function () {
        window.localStorage.setItem('assessments', JSON.stringify(self.assessmentCache));
    };