Question

I have a stringified JSON object that appears properly in an alert, appears properly in the post section in the browser debugger, but in the controller it appears as null. I’m not sure how it is losing the information.

Here is the JS code:

 var assessmentStatus = [];

            $("select.assessmentSelect").each(function () {
                assessmentStatus.push({
                    assessmentname: $(this).attr("id"),
                    assessmentstatus: $(this).val()
                });


            });
alert(JSON.stringify(assessmentStatus));


            $.ajax({
                url: '@Url.Action("testAS")',
                type: "POST",
                contentType: 'application/json',
                data: JSON.stringify({
                    AS: assessmentStatus,
                    AS2: assessmentStatus

                })

            });

this is what is appearing in the alert:

[{"assessmentname":"testassessment","assessmentstatus":"Design"},{"assessmentname":"DepressionUpload","assessmentstatus":"Design"}]

this is what is appearing in the post:

[Object { assessmentname="testassessment", assessmentstatus="Design"}, Object { assessmentname="DepressionUpload", assessmentstatus="Design"}]

my controller looks like this:

public ActionResult testAS (string[] AS, string AS2)

string[] AS returns [0]null  [1]null
string AS2 just returns null.

Why is it not getting stringified when being sent to the controller?

Answer 1

You seem to be attempting to pass an array of complex objects with 2 properties:

assessmentStatus.push({
    assessmentname: $(this).attr("id"),
    assessmentstatus: $(this).val()
});

to a simple array of strings: string[] as. This is obviously not gonna work.

So start by defining a view model:

public class AssessmentViewModel
{
    public string Name { get; set; }
    public string Status { get; set; }
}

then adapt your controller action:

public ActionResult TestAS(AssessmentViewModel[] assessments)
{
    ...
}

and finally your javascript:

var assessments = [];
$('select.assessmentSelect').each(function () {
    assessments.push({
        name: $(this).attr("id"),
        status: $(this).val()
    });
});
$.ajax({
    url: '@Url.Action("testAS")',
    type: "POST",
    contentType: 'application/json',
    data: JSON.stringify({ assessments: assessments })
});