asp.net mvc Ajax.BeginForm clone - asp.net-mvc

Question

I'm using asp.net mvc ajax.
The partial view is using Ajax.BeginForm (just an example):
<div id="divPlaceholder">
<% using (Ajax.BeginForm(new AjaxOptions { UpdateTargetId = "divPlaceholder" })) { %>
... asp.net mvc controls and validation messages
<input type="submit" value="Save" />
<% } %>
</div>
After update, if validation fails, the html is:
<div id="divPlaceholder">
<div id="divPlaceholder">
...form
</div>
</div>
I don't like that the returned html is inserted, instead it should replace original div.
Probably on POST I should not render <div> around form in partial view or render the div without id.
What else can I do in this situation?
I was thinking that maybe I should write a helper, something like Ajax.DivBeginForm, which will render form inside div on GET and hide the div on POST.
Can somebody provide a good advice how to write such helper (Ajax.DivBeginForm)?
I'd like it to work with using keyword:
<% using (Ajax.DivBeginForm(new AjaxOptions { UpdateTargetId = "myId" })) { ... }%>

Answer 1

My solution. Please comment if something is wrong.
public class DivMvcForm : MvcForm
{
private bool _disposed;
private MvcForm mvcForm;
private ViewContext viewContext;
public DivMvcForm(MvcForm mvcForm, ViewContext viewContext) : base(viewContext)
{
this.mvcForm = mvcForm;
this.viewContext = viewContext;
}
protected override void Dispose(bool disposing)
{
if (!_disposed)
{
_disposed = true;
mvcForm.EndForm();
viewContext.Writer.Write("</div>");
}
}
}
Helper
public static class AjaxHelperExtensions
{
public static MvcForm DivBeginForm(this AjaxHelper ajaxHelper, AjaxOptions ajaxOptions)
{
var tagBuilder = new TagBuilder("div");
if (ajaxHelper.ViewContext.HttpContext.Request.RequestType == "GET"
&& string.IsNullOrWhiteSpace(ajaxOptions.UpdateTargetId) != true)
{
tagBuilder.MergeAttribute("id", ajaxOptions.UpdateTargetId);
}
ajaxHelper.ViewContext.Writer.Write(tagBuilder.ToString(TagRenderMode.StartTag));
var theForm = ajaxHelper.BeginForm(ajaxOptions);
return new DivMvcForm(theForm, ajaxHelper.ViewContext);
}
}
And how it works
<% using (Ajax.DivBeginForm(new AjaxOptions { UpdateTargetId = "divPlaceholder" })) { %>
... controls
<% } %>
Result - when ModelState is invalid the partial view returns div without id.

Answer 2

I'm going to take a little different approach here, rather than getting your original solution to work, I'd recommend using the pattern normally followed in this scenario and not using a helper. I realize this is a bit later than the original post, but for future use by anyone : )
If your partial view has a form, then you will keep posting, and returning a form in a form in a form in a form, etc. so you want to have your PARENT contain BeginForm, the div, and renderpartial
using (Ajax.BeginForm("Index", "ProjectManager", new AjaxOptions() ....
<div id="divPlaceholder">
Html.RenderPartial(....)
</div>
If you want to encapsulate this logic in say, an "Order" partial view that is displayed on a Customer screen, then you have two options.
1. Include the BeginForm on the parent Customer view (which reduces code reusability as any view that wants to include the "Order" partial view must include the ajax wiring.
Or
2. You have two partial views for order. One is OrderIndex.ascx (or cshtml if razor) and one is OrderIndexDetail.ascx (or whatever naming convention you decide)
OrderIndex contains your Ajax.beginform and OrderIndexDetail has no form, only the partial view details.
Option 2 is more code (ok, literally about 30 more seconds of coding to move the ajax.beginform into another view) but increases code reusability.

Answer 3

You can handle submit form yourself:
<div id="divPlaceholder">
<% using (Html.BeginForm("action", "controller", FormMethod.Post, new { id = "submitForm"})) { %>
... asp.net mvc controls and validation messages
<input type="submit" value="Save" />
<% } %>
</div>
and write some javascript as:
$('#submitForm').submit(function() {
$.post('post-to-this-url',
data: { foo: formvalue1, bar: formvalue2},
function(data) {
// update html here
});
return false;
})