Asp.Net MVC2 Clientside Validation problem with controls with prefixes

Question

The problem is: when I put 2 controls of the same type on a page I need to specify different prefixes for binding. In this case the validation rules generated right after the form are incorrect. So how to get client validation work for the case?:

the page contains:

<%
    Html.RenderPartial(ViewLocations.Shared.PhoneEditPartial, new PhoneViewModel { Phone = person.PhonePhone, Prefix = "PhonePhone" });
    Html.RenderPartial(ViewLocations.Shared.PhoneEditPartial, new PhoneViewModel { Phone = person.FaxPhone, Prefix = "FaxPhone" });
%>

the control ViewUserControl<PhoneViewModel>:

<%= Html.TextBox(Model.GetPrefixed("CountryCode"), Model.Phone.CountryCode) %>
<%= Html.ValidationMessage("Phone.CountryCode", new { id = Model.GetPrefixed("CountryCode"), name = Model.GetPrefixed("CountryCode") })%>

where Model.GetPrefixed("CountryCode") just returns "FaxPhone.CountryCode" or "PhonePhone.CountryCode" depending on prefix

---

And here is the validation rules generated after the form. They are duplicated for the field name "Phone.CountryCode". While the desired result is 2 rules (required, number) for each of the FieldNames "FaxPhone.CountryCode", "PhonePhone.CountryCode" alt text http://www.freeimagehosting.net/uploads/37fbe720bf.png

The question is somewhat duplicate of Asp.Net MVC2 Clientside Validation and duplicate ID's problem but the advise to manually generate ids doesn't helps.

Predictor

Answer 1

Correct way to set the same prefixes both for textbox and validation:

<% using (Html.BeginHtmlFieldPrefixScope(Model.Prefix)) { %>
   <%= Html.TextBoxFor(m => m.Address.PostCode) %>
   <%= Html.ValidationMessageFor(m => m.Address.PostCode) %>
<% } %>

where

public static class HtmlPrefixScopeExtensions
{
    public static IDisposable BeginHtmlFieldPrefixScope(this HtmlHelper html, string htmlFieldPrefix)
    {
        return new HtmlFieldPrefixScope(html.ViewData.TemplateInfo, htmlFieldPrefix);
    }

    private class HtmlFieldPrefixScope : IDisposable
    {
        private readonly TemplateInfo templateInfo;
        private readonly string previousHtmlFieldPrefix;

        public HtmlFieldPrefixScope(TemplateInfo templateInfo, string htmlFieldPrefix)
        {
            this.templateInfo = templateInfo;

            previousHtmlFieldPrefix = templateInfo.HtmlFieldPrefix;
            templateInfo.HtmlFieldPrefix = htmlFieldPrefix;
        }

        public void Dispose()
        {
            templateInfo.HtmlFieldPrefix = previousHtmlFieldPrefix;
        }
    }
}

(by chance found the solution in the code on Steve Sanderson's blog http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/)

Also looks like Html.EditorFor approach should work as well as suggested here: ASP.NET MVC 2 - ViewModel Prefix

Predictor

Nice. This answer was very helpful. Wish I could upvote it a couple more times. – Lycopodium

I know this is an old answer, but I was wondering if your method is preferable to putting this in your view: ViewData.TemplateInfo.HtmlFieldPrefix = "myViewModel.MyCustomObjdect"; – Uund

Yes, cause it does the same in DRY manner and more: it restores previous HtmlFieldPrefix in Dispose method. – Predictor

I think this should be a part of MVC core functionality – Proa