Getting a Partial View's HTML from inside of t

Question

I have developed a simple mechanism for my mvc website to pull in html via jquery which then populates a specified div. All is well and it looks cool.
My problem is that i'm now creating html markup inside of my controller (Which is very easy to do in VB.net btw) I'd rather not mix up the sepparation of concerns.

Is it possible to use a custom 'MVC View User Control' to suit this need? Can I create an instance of a control, pass in the model data and render to html? It would then be a simple matter of rendering and passing back to the calling browser.

Answer 1

In rails this is called rendering a partial view, and you do it with render :partial => 'yourfilename'. I believe ASP.NET MVC has a similar RenderPartial method, but I can't find the official docs for MVC to confirm or deny such a thing.

Answer 2

This is a solution that is working with ASP.Net MVC 1.0 (many that claim to work with beta 3 don't work with 1.0), doesn't suffer of the 'Server cannot set content type after HTTP headers have been sent' problem and can be called from within a controller (not only a view):

/// <summary>
/// Render a view into a string. It's a hack, it may fail badly.
/// </summary>
/// <param name="name">Name of the view, that is, its path.</param>
/// <param name="data">Data to pass to the view, a model or something like that.</param>
/// <returns>A string with the (HTML of) view.</returns>
public static string RenderPartialToString(string controlName, object viewData) {
    ViewPage viewPage = new ViewPage() { ViewContext = new ViewContext() };
    viewPage.Url = GetBogusUrlHelper();

    viewPage.ViewData = new ViewDataDictionary(viewData);
    viewPage.Controls.Add(viewPage.LoadControl(controlName));

    StringBuilder sb = new StringBuilder();
    using (StringWriter sw = new StringWriter(sb)) {
        using (HtmlTextWriter tw = new HtmlTextWriter(sw)) {
            viewPage.RenderControl(tw);
        }
    }

    return sb.ToString();
}

public static UrlHelper GetBogusUrlHelper() {
  var httpContext = HttpContext.Current;

  if (httpContext == null) {
    var request = new HttpRequest("/", Config.Url.ToString(), "");
    var response = new HttpResponse(new StringWriter());
    httpContext = new HttpContext(request, response);
  }

  var httpContextBase = new HttpContextWrapper(httpContext);
  var routeData = new RouteData();
  var requestContext = new RequestContext(httpContextBase, routeData);

  return new UrlHelper(requestContext);
}

It's a static method you can drop somewhere you find it convenient. You can call it this way:

string view = RenderPartialToString("~/Views/Controller/AView.ascx", someModelObject); 

Answer 3

it is very simple you just have to create a strongly typed partial view(or user control) then in your cotroller something like this:

public PartialViewResult yourpartialviewresult()
{
    var yourModel
    return PartialView("yourPartialView", yourModel);
}

then you can use JQuery to perform the request whener you want:

$.ajax({
    type: 'GET',
    url: '/home/yourpartialviewresult',
    dataType: 'html', //be sure to use html dataType
    contentType: 'application/json; charset=utf-8',
    success: function(data){
         $(container).html(data);
    },
    complete: function(){ }
 });    

Answer 4

You should use jquery to populate your divs (and create new html elements if needed), and Json serialization for ActionResult.

Other way is to use jquery to call some controller/action, but instead json use regular View (aspx or ascx, webforms view engine) for rendering content, and with jquery just inject that html to some div. This is half way to UpdatePanels from asp.net ajax...

I would probably go with first method, with json, where you have little more job to do, but it's much more "optimized", because you don't transfer whole html over the wire, there are just serialized objects. It's the way that "big ones" (gmail, g docs, hotmail,..) do it - lot of JS code that manipulates with UI.

If you don't need ajax, then you basically have two ways of calling partial views:

• html.renderpartial("name of ascx")
• html.RenderAction(x=>x.ActionName) from Microsoft.web.mvc (mvc futures)