Javascript Angular服务在返回承诺时引发异常

在我的app.js代码中，我运行了一些init代码，从服务器中提取会话变量

到目前为止还不错；然而，我现在尝试添加一个额外的调用来为treeview小部件提取数据。此新调用导致JavaScript异常：

  "Cannot read property 'then' of undefined"

启动代码为：

1) app.run gets called first,

2) call into 'userService' to init various $rootScope vars

3) userService makes API calls to a server and returns data. $q.defer() and $http is used

**接下来的步骤会导致异常

4) call into userService.getUserReportsTreeFromDataContext() from app.run

5) userService.getUserReportsTreeFromDataContext then calls down into datacontext.js (THIS SOMEHOW CAUSES AN EXCEPTION).

这是app.so中我的app.run（）代码

app.run(['$route', '$rootScope', 'common', 'userService', function ($route, $rootScope, common, userService) {
 // initialize session vars     
   userService.openUserSession(razorEnvJson).then(function (data) {
            var sessionID = data.data[0];
            $rootScope.rageSessionVars.sessionID = sessionID;

            // **** THROWS EXCEPTION HERE ****                     
            userService.getUserReportsTreeFromDataContext().then(function (data){
                       // var myData = data;   
            });
    });
 }]);    

以及userContext.js服务中的一个片段：

 this.openUserSession = function (razorEnvParams) {
        _razorEnvParams = razorEnvParams;

        _// some vars ommitted here for brevity
        var url = "http://" + _domain + ":" + _port + controllerpath + "?userid=" + user + "&pass=" + pass;
        var deferred = $q.defer();
        deferred.notify("Opening user session...");
        var retval = [];
        $http({
            method: 'GET',
            encoding: 'JSON',
            headers: {
                'Access-Control-Allow-Origin': 'true',
                'Content-Type': 'application/json'
            },
            withCredentials: true,
            url: url
        }).success(function (data, status, headers, config) {
            retval = data;
            deferred.resolve(retval);
        }).error(function (data, status, headers, config) {
            log("Cannot open a user session via api call. Errors details: " + data);
        });
        return deferred.promise;
    }

    this.getUserReportsTreeFromDataContext = function (userID) {         
        datacontext.getReportsTree().then(function (data) {
             return data;
        });            
    }

以及我的datacontext.js代码，用于从服务器提取数据，或提取一些测试数据：

   (function () {
'use strict';

var serviceId = 'datacontext';
angular.module('app').factory(serviceId, ['$http', '$rootScope', 'common', datacontext]);

function datacontext($http, $rootScope, common) {
    var $q = common.$q;

     var service = {
        getReportsTree: getReportsTree,
        sendAggrRequestToServer: sendAggrRequestToServer,            
    };

    return service;

    function getReportsTree() {
        var reportsJson = [
            {
              id: 1, text: "Standard", expanded: false, spriteCssClass: "rootfolder", checkChildren: true, items: [ 
            { id: 3, text: "MTM Aggr", reptName: "MTM Aggr" },
            { id: 4, text: "Member Aggr", reptName: "Member Aggr"                }                                
        ]
},
{
    id: 30, text: "Hierarchy", expanded: false, spriteCssClass: "rootfolder", checkChildren: true, items: [
        { id: 31, text: "Ctpy Hrchy", reptName: "CTPYHIER", withHierarchy: 'true' },
        { id: 32, text: "Ctpy/BkgLocation Hrchy", reptName: "CTPYHIER_BKG_LOC", withHierarchy: 'true' }
    ]
}                          
];
        return $q.when(reportsJson);
    }
  })();  // end datacontext.js

仅供参考-我从dashboard.js控制器到datacontext.js进行了许多其他成功调用，没有任何问题

下面是一个很好的示例，其中一些测试数据来自datacontext：

dashboard.js-

    function getPositionsData() {
        datacontext.getPositions().then(function (data) {
            vm.positionsData = data;
            populateGridDataSource(vm.positionsData);
        });
    }

datacontext.js-

   function getPositions() {
        var positionsJson = [
            { id: 1, product: "BAX", instrument: "BOND-0003", position: 11, delta: 0.02, gamma: 0.79, initMarin: 600, initMarginPctChange: 250, varMargin: 75 },
            { id: 2, product: "BAX", instrument: "BOND-0004", position: -4, delta: 0.12, gamma: 0.46, initMarin: 400, initMarginPctChange: 300, varMargin: 65 },
            { id: 3, product: "BAX", instrument: "BOND-0004", position: 9, delta: 0.09, gamma: 0.55, initMarin: 700, initMarginPctChange: 200, varMargin: 40 }
        ];
        return $q.when(positionsJson);
    }

---

您忘记在

getUserReportsTreeFromDataContext

函数中返回初始承诺：应如下所示：

this.getUserReportsTreeFromDataContext = function (userID) 
{ return datacontext.getReportsTree()
         .then(function (data) { return data; }); 
} 

---

您忘记在getUserReportsTreeFromDataContext函数中返回初始承诺：应该是这样的：this.getUserReportsTreeFromDataContext=function（userID）{return datacontext.getReportsTree（）。然后（function（data）{return data；}）；}天哪，您说得对！换句话说，我在数据完成后返回数据，然后返回实际承诺。非常感谢。请添加准确的帖子作为您的答案！你能看一下吗？对不起，我检查了问题，但我对这个问题一无所知。