Getting status 500 when using angularjs $http to get data from server

Question

I am working on an asp.net mvc application and I am using Entity Framework and AngularJS in it. I am using AngularJS's $http service to call an action method and retrieve data from the server. The correct data is retrieved from the server (I confirmed this by debugging), but somehow an error occurs after the action method returns the retrieved data and the error callback function is fired instead of the success callback function. And then I get a status 500 in the browser's console.

Here are the involved blocks of codes:

(From angularjs controller)

    $http({
        url: rootUrl + "User/GetUser",//'@Url.Action("GetUser","User")',
        method: 'POST',
        params: {
            uname: $scope.username,
            pword: $scope.pass
        }
    }).then(function (response) {
        alert('success!');
        $scope.user = response.data;
        if ($scope.user.Fullname != undefined) {
            $http({
                url: rootUrl + "Session/Set",
                method: "POST",
                data: {
                    "key": "curr_user",
                    "value": JSON.stringify($scope.user)
                }
            });

            window.location.href = rootUrl + 'Product/List/';

        } else {
            //invalid login
            $("input[name='password']").select();
            $("#validation-summary").html("Wrong email or password.");
            $scope.invalidlogin = true;
            $(btnLogin).removeClass('disabled');
            $(btnLogin).text("Submit");

        }

(From mvc controller)

    [HttpPost]
    public JsonResult GetUser(string uname, string pword)
    {
        JBManager manager = null;

        using (SE_Context db = new SE_Context())
        {
            try
            {
                manager = db.Managers
                    .Include("Transactions.Items")
                    .Where(m => m.Username == uname && m.Password == pword)
                    .FirstOrDefault();
                //At this point, manager has the desired data
                return Json(manager, JsonRequestBehavior.AllowGet);
            }
            catch (Exception ex)
            {
                return null;
            }
        }
    }

And here's a screenshot of the error in the browser:

Would really appreciate any help. Thanks!

UPDATE: Everything was working fine before I used Entity Framework. (Just in case it has something to do with the issue)

Answer 1

I think your issue is nested objects.You can flatten object graphs that contain nested objects using DTOs (Data Transfer Objects).

You can just try simple example as like below.If it'll work then you need to extend it to work with your EF query.

public class MyDto
    {
        public string Name { get; set; }
    }


    [HttpPost]
    public JsonResult GetUser(string uname, string pword)
    {
        JBManager manager = null;

        using (SE_Context db = new SE_Context())
        {
            try
            {
               //construct the DTO here
                manager = db.Managers.Select(a=> new MyDto(
                {
                 Name = a.Name
                 })).FirstOrDefault(m => m.Username == uname && m.Password == pword);

                return Json(manager, JsonRequestBehavior.AllowGet);
            }
            catch (Exception ex)
            {
                return null;
            }
        }
    }

You can read more about DTOs here : Create Data Transfer Objects (DTOs)