MVC Ajax - Parsing Form Submission Return Data

Question

I am using MVC Ajax to do a form submission. What I can't get right is to get the Action on the server to return a partial view to the browser.

The form submission looks like this:

<% using (Ajax.BeginForm("Add", "Example", new AjaxOptions { HttpMethod = FormMethod.Post.ToString(), OnComplete = "widgetAdded" } )) { %>

This hits the server and the action gets executed. The JavaScript method 'widgetAdded' that gets executed after the action completes looks something like this:

function widgetAdded(ajaxContext) {
    var response = ajaxContext.get_response().get_object();
    alert(response);
}

If I return a Json result in the action like this, it works - the alert shows the data being passed from the server.

return Json("bob");

Now if I change the action to return a PartialView like this, it doesn't work.

return PartialView("Widgets");

I've tried to interrogate the response object in Firebug, but I can't seem to get the actual view html. Any ideas?

Answer 1

You could render your partial view to a string, and return the string:

        public static string RenderPartialToString(string controlName, object viewData, object model, System.Web.Routing.RequestContext viewContext)
        {

            ViewDataDictionary vd = new ViewDataDictionary(viewData);
            ViewPage vp = new ViewPage { ViewData = vd };

            vp.ViewData = vd;
            vp.ViewData.Model = model;
            vp.ViewContext = new ViewContext();
            vp.Url = new UrlHelper(viewContext);

            Control control = vp.LoadControl(controlName);

            vp.Controls.Add(control);

            StringBuilder sb = new StringBuilder();

            using (StringWriter sw = new StringWriter(sb))
            {

                using (HtmlTextWriter tw = new HtmlTextWriter(sw))
                {

                    vp.RenderControl(tw);

                }

            }

            return sb.ToString();

        }

Code above taken from here

Answer 2

To get the actual view html use:

alert(ajaxContext.get_response().get_responseData());

The get_object() function works only with JSON content.

Answer 3

I did some more research and it seems it's not possible to return a view as the response to a POST action. I looked at the actual response being sent to the client - if I return a string (as Json) the response header actually gets populated - if I return a view the response header is empty.

It seems like the best solution is to simply do another GET (using JQuery) and retrieving the View manually.