Question

I’m having an issue with using AJAX in MVC3. The problem is as I’m debugging the project, I see that the controller is getting the appropriate values passed in, I see that the query is being generated properly and is returning the same result as I get when I test it in LINQPad. When the query returns an empty result set, I don’t get any errors. However, when there is data in the result set I get an “Internal Server Error”. It seems that the problem lies is passing the JSON result from the controller to the view.

I have the code below.

Controller Code

[HttpPost]
public ActionResult Load(int value1, int value2, int value3)
{
    var db = new MyDataContext();
    List<Foo> items = new List<Foo>();
    items = db.Foos.Where(f => f.v1 == value1 && f.v2 == value2 && f.v3 == value3).Take(50).ToList();
    var results = Json(items, JsonRequestBehavior.AllowGet);
    return results;
}

JQuery/Javascript Code

function Load() {
    var v1 = 3;
    var v2 = 2;
    var v3 = 1;

    $.ajax({
        type: 'POST',
        dataType: 'json',
        url: '/FooBar/Load',
        data: { value1: v1, value2: v2, value3: v3 },
        error: function (xhr, status, error) {
            alert('Error loading: "' + error + '"');
        },
        success: function (jsonresults) {

        }
    });
}

If someone could take a second look I would greatly appreciate it.

Answer 1

Try changing your action method to return a JsonResult instead of an ActionResult. It’s the only thing I can see that you’re doing wrong, as I am doing pretty much the same thing and it’s working as intended, but my controller method return a JsonResult.

Also, check out this link as it may or may not be helpful. It saved my butt a couple days ago:

http://blog.janjonas.net/2011-08-07/asp_net-mvc_3-jquery-ajax-submit-ajax-form-supporting-unobtrusive-client-side-validation-and-server-side-validation