嵌套的承諾返回未定義

Question

我在嵌套服務中有一個問題，在角度服務中，我有以下方法：

this.get = function (matchId, teamId) {
    var _key = matchId + '_' + teamId;
    var self = this;
    var alivePromise = $apiService.alive();
    alivePromise.success(function () {
        var getPromise = $apiService.get(matchId, teamId);
        getPromise.success(function (response) {
            self.clearLocal().then(function () {
                return self.pushToLocal({ ots: _key, data: response })
                .then(function () {
                    return self.fetchFromLocal(_key);
                });
            })
        });
        getPromise.error(function (response) {
            return self.fetchFromLocal(_key);
        });
    });
    alivePromise.error(function () {
        return self.fetchFromLocal(_key);
    });
};

this.fetchFromLocal = function (key) {
        return $indexedDB.openStore('teamsheets', function (store) {
            store.find(key);
        });
    }
    this.pushToLocal = function (data) {
        return $indexedDB.openStore('teamsheets', function (store) {
            store.upsert(data);
        });
    };

在控制器內部，我想以這種方式調用此方法：

$dataProvider.get(MATCH_ID, TEAM_ID)
        .then(function (result) {
            $scope.teamsheet = result;
            $scope.masterCopy = JSON.parse(JSON.stringify(result));

        });

但是我總是檢索以下錯誤：

angular.min.js:107 TypeError: Cannot read property 'then' of undefined
    at new <anonymous> (team-sheet-details-controller.js:3)
    at Object.e [as invoke] (angular.min.js:39)
    at Q.instance (angular.min.js:80)
    at L (angular.min.js:61)
    at g (angular.min.js:54)
    at g (angular.min.js:54)
    at angular.min.js:53
    at angular.min.js:20
    at m.$eval (angular.min.js:132)
    at m.$apply (angular.min.js:133)

我做錯了什么？

Answer 1

如果this.get是$ dataProvider上的get函數，請嘗試以下代碼：

this.get = function (matchId, teamId) {
    var _key = matchId + '_' + teamId;
    var self = this;

    return $apiService.alive().then(function () {
        return getPromise = $apiService.get(matchId, teamId);
        getPromise.success(function (response) {
            self.clearLocal().then(function () {
                return self.pushToLocal({ ots: _key, data: response })
                .then(function () {
                    return self.fetchFromLocal(_key);
                });
            })
        });
        getPromise.error(function (response) {
            return self.fetchFromLocal(_key);
        });
    }, function () {
        return self.fetchFromLocal(_key);
    });
};