How to view the controller's resulting html in debug with ASP.NET MVC?

Question

Is there a way that I can see, while debugging, the result (html, xml, json) of a Controller's action.

For instance, I have this in my controller:

    public PartialViewResult Reload()
    {
        return PartialView("Index");
    }

While debugging, I'd like to see what HTML will be sent back to the client. Thanks

Answer 1

It is not easy, because partial view result is sent directly to httpcontext.current.response.output, it doesn't return string. You can use this extension method to catch it as string by filtering httpcontext output:

    /// <summary>Renders a view to string.</summary>
    public static string RenderViewToString(this Controller controller,
                                            string viewName, object viewData)
    {
        //Getting current response
        var response = HttpContext.Current.Response;
        //Flushing
        response.Flush();

        //Finding rendered view
        var view = ViewEngines.Engines.FindPartialView(controller.ControllerContext, viewName).View;
        //Creating view context
        var viewContext = new ViewContext(controller.ControllerContext, view,
                                          controller.ViewData, controller.TempData);

        //Since RenderView goes straight to HttpContext.Current, we have to filter and cut out our view
        var oldFilter = response.Filter;
        Stream filter = new MemoryStream(); ;
        try
        {
            response.Filter = filter;
            viewContext.View.Render(viewContext, null);
            response.Flush();
            filter.Position = 0;
            var reader = new StreamReader(filter, response.ContentEncoding);
            return reader.ReadToEnd();
        }
        finally
        {
            filter.Dispose();
            response.Filter = oldFilter;
        } 
    }

and use it like this during debug:

public PartialViewResult Reload()
{
    var result = RenderViewToString("Index",ViewData);
    return PartialView("Index");
}

Extension method for Spark:

    public static string RenderSparkToString(this Controller controller,
                                            string viewName, object viewData)
    {
        var view = ViewEngines.Engines.FindPartialView(controller.ControllerContext, viewName).View;
        //Creating view context
        var viewContext = new ViewContext(controller.ControllerContext, view,
                                          controller.ViewData, controller.TempData);

        var sb = new StringBuilder();
        var writer = new StringWriter(sb);

        viewContext.View.Render(viewContext, writer);
        writer.Flush();
        return sb.ToString();
    }

Answer 2

What prevents you from just hitting the Route that renders the partial view and view source?

Answer 3

Browser will show the result anyway

Why would you want to see it in debug mode, while you can see it in your browser anyway. That's where it goes afterwards anyway. If JSON is in question use Firefox + Firebug and you'll see all requests and responses with all related data and info.

If you tell us why exactly would you like to do this, we may suggest a better way of getting you there...