Javascript 服务返回承诺，但大笑服务不返回

我正在调用getWeeklyDates，它正在调用cachingGlobalConfiguration服务，如果在本地存储中找不到globalConfiguration数据，它将再次调用globalConfiguration服务

代码=>

return cachingGlobalConfigurationService.getGlobalConfiguration()
                   .then(function(response1){

当globalConfiguration尚未缓存时，它可以正常工作，因为我会调用ajax并返回一个承诺

但是当可以在本地存储中找到我的全局配置时，上面带有.thenfunctionresponse1的代码行是未定义的，只返回以下内容：

 else {
          return cachedGlobalConfiguration;
        }

我想我不能用。那么在这种情况下，我想

我怎样才能解决这个问题

一,

二,

三,

})

您可以注入$q服务，并在返回时使用它来包装对象，这样您就可以始终从api中返回承诺，并删除多余的else。如果需要的话，还记得拒绝承诺

'use strict';
angular.module('test').service('cachingGlobalConfigurationService', function (localStorageService, globalConfigurationService, $q) {
  this.getGlobalConfiguration = function () {

    var cachedGlobalConfiguration = localStorageService.get('globalConfiguration');
    if (cachedGlobalConfiguration) {
        //Return a promise
        return $q.when(cachedGlobalConfiguration);
     }

     return globalConfigurationService.getGlobalConfiguration().then(
        function (globalConfiguration) {
          localStorageService.set('globalConfiguration', globalConfiguration);
          return globalConfiguration;
        },
        function (error) {
          console.log('error', error);
          return $q.reject(error); //<-- reject
        });
  };

  //....
});

$q.when-将可能是值或第三方的对象包装为$q承诺。当您处理的对象可能是承诺，也可能不是承诺，或者承诺来自不可信任的来源时，这非常有用

'use strict';
angular.module('test').service('cachingGlobalConfigurationService', function (localStorageService, globalConfigurationService) {
  this.getGlobalConfiguration = function () {

    var cachedGlobalConfiguration = localStorageService.get('globalConfiguration');
    if (!cachedGlobalConfiguration) {
      return globalConfigurationService.getGlobalConfiguration().then(
        function (globalConfiguration) {
          localStorageService.set('globalConfiguration', globalConfiguration);
          return globalConfiguration;
        },
        function (error) {
          console.log('error', error);
        });
    }
    else {
      return cachedGlobalConfiguration;
    }
  };

  this.saveGlobalConfiguration = function (globalConfiguration) {

    // TODO: Only save to local storage when service.save was successfully
    localStorageService.set('globalConfiguration', globalConfiguration);
    globalConfigurationService.saveGlobalConfiguration(globalConfiguration);
  }
});

'use strict';
angular.module('test').service('globalConfigurationService', function ($http) {
  this.getGlobalConfiguration = function () {

    // TODO get from db
    var path = 'scripts/model/globalConfiguration.json';
    return $http.get(path).then(function (response) {
      return response.data.globalConfiguration;
    });
  };

  this.saveGlobalConfiguration = function (globalConfiguration) {

    // TODO: save on db
    //var path = 'scripts/model/globalConfiguration.json';
    //return $http.post(path, globalConfiguration).then(function (response) {
    //  alert('global configuration was saved succesfully!');
    //});
  }

'use strict';
angular.module('test').service('cachingGlobalConfigurationService', function (localStorageService, globalConfigurationService, $q) {
  this.getGlobalConfiguration = function () {

    var cachedGlobalConfiguration = localStorageService.get('globalConfiguration');
    if (cachedGlobalConfiguration) {
        //Return a promise
        return $q.when(cachedGlobalConfiguration);
     }

     return globalConfigurationService.getGlobalConfiguration().then(
        function (globalConfiguration) {
          localStorageService.set('globalConfiguration', globalConfiguration);
          return globalConfiguration;
        },
        function (error) {
          console.log('error', error);
          return $q.reject(error); //<-- reject
        });
  };

  //....
});