Using Ajax.BeginForm with ASP.NET MVC 3 Razor

Question

Is there a tutorial or code example of using Ajax.BeginForm within Asp.net MVC 3 where unobtrusive validation and Ajax exist?

This is an elusive topic for MVC 3, and I cannot seem to get my form to work properly. It will do an Ajax submit but ignores the validation errors.

Answer 1

Example

//In Model

public class MyModel
{  
   [Required]
    public string Name{ get; set; }
}

//In PartailView //PartailView.cshtml

@model MyModel

<div>
    <div>
      @Html.LabelFor(model=>model.Name)
    </div>
    <div>
        @Html.EditorFor(model=>model.Name)
        @Html.ValidationMessageFor(model => model.Name)
    </div>
</div>

In Index.cshtml view

@model MyModel
<div id="targetId">
    @{Html.RenderPartial("PartialView",Model)}
</div>

@using(Ajax.BeginForm("AddName", new AjaxOptions { UpdateTargetId = "targetId", HttpMethod = "Post" }))
{
     <div>
        <input type="submit" value="Add Unit" />
    </div>
}

In Controller

public ActionResult Index()
{
  return View(new MyModel());
}


public string AddName(MyModel model)
{
   string HtmlString = RenderPartialViewToString("PartailView",model);
   return HtmlString;
}


protected string RenderPartialViewToString(string viewName, object model)
        {
            if (string.IsNullOrEmpty(viewName))
                viewName = ControllerContext.RouteData.GetRequiredString("action");

            ViewData.Model = model;

            using (StringWriter sw = new StringWriter())
            {
                ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(ControllerContext, viewName);
                ViewContext viewContext = new ViewContext(ControllerContext, viewResult.View, ViewData, TempData, sw);
                viewResult.View.Render(viewContext, sw);
                return sw.GetStringBuilder().ToString();
            }
        }

you must be pass ViewName and Model to RenderPartialViewToString method. it will return you view with validation which are you applied in model and append the content in "targetId" div in Index.cshtml. I this way by catching RenderHtml of partial view you can apply validation.

Answer 2

Ajax forms work asynchronously using Javascript. So it is required, to load the script files for execution. Even though it's a small performance compromise, the execution happens without postback.

We need to understand the difference between the behaviours of both Html and Ajax forms.

Ajax:

1. Won't redirect the form, even you do a RedirectAction().

2. Will perform save, update and any modification operations asynchronously.

Html:

1. Will redirect the form.

2. Will perform operations both Synchronously and Asynchronously (With some extra code and care).

Demonstrated the differences with a POC in below link. Link