MVC 3 dropdownlist validation not working for complex view model RSS

• • Reply
  

  mreyeros

  Contributor

  4022 Points

  736 Posts

  MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 02:19 AM|LINK

  Good evening everyone I have a question regarding validation of drop-down list values. I have a view that is bound to a view model type called ReservationData.

  This object contains a property CustomerVehicles of type List<VehicleData>. VehicleDatahas two int properties VehicleMakeId and VehicleModelId.

  On my view I am trying to loop over the number of items in the CustomerVehicles collection and displaying two dropdowns for each, a vehicle make dropdown and a vehicle model dropdown usingDropDownListFor.

  When I try to submit and validate I do not see any validation errors displayed on the screen.

  Just in case you are wondering I have added a ValidationMessageFor for each dropdown as well. I am not sure if this is an issue with the structure of my view model and its complexity and how the controls need to be named or how the ids need to be set. Any help would be greatly appreciated.

  Here is the code for the looping over the collection:

  @for (var i = 0; i < Model.CustomerVehicles.Count(); i++)
      {
          var vehicleNumber = i + 1;
          <div class="vehicle-selection-wrapper">
              <div class="content-container">
                  <h3>
                      Vehicle @vehicleNumber</h3>
                  <img class="vehicle-image" alt="manufacturer image" src="@Url.Content("~/Content/images/default-vehicle.gif")" /><br />
                  @Html.LabelFor(m => m.CustomerVehicles[i].VehicleMakeId)
                  @Html.DropDownListFor(m => m.CustomerVehicles[i].VehicleMakeId
              , new SelectList(Model.VehicleMakes, "Id", "Name")
                            , @UIDisplay.Dropdown_DefaultOption, new { @class = "long-field" })<br />
                  @Html.ValidationMessageFor(m => m.CustomerVehicles[i].VehicleMakeId)<br />
                  @Html.LabelFor(m => m.CustomerVehicles[i].VehicleModelId)
                  @Html.DropDownListFor(m => m.CustomerVehicles[i].VehicleModelId
              , new SelectList(new List<CWR.Domain.VehicleModel>(), "Id", "Name")
                   , @UIDisplay.Dropdown_DefaultOption, new { @class = "long-field" })
                  @Html.ValidationMessageFor(m => m.CustomerVehicles[i].VehicleModelId)
              </div>
          </div>
      }

  
  
  

  Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
• • Reply
  

  raduenuca

  All-Star

  24675 Points

  4250 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 05:16 AM|LINK

  Hi,

  Can you show the VehicleData model? Do you have any DataAnnotations attribute on those properties (like Required)? 

  Please click 'Mark as Answer' if my reply has assisted you
  
  Radu Enuca | Blog
• • Reply
  

  mreyeros

  Contributor

  4022 Points

  736 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 02:14 PM|LINK

  public class VehicleData
      {
          [Display(Name="VehicleData_VehicleMake", ResourceType=typeof(UIDisplay))]
          [Required(ErrorMessageResourceName="VehicleData_VehicleMakeRequired"
              , ErrorMessageResourceType=typeof(UIValidation)
              , AllowEmptyStrings = false)]
          public int VehicleMakeId { get; set; }
          [Display(Name = "VehicleData_VehicleModel", ResourceType = typeof(UIDisplay))]
          [Required(ErrorMessageResourceName = "VehicleData_VehicleModelRequired"
              , ErrorMessageResourceType = typeof(UIValidation)
              , AllowEmptyStrings=false)]
          public int VehicleModelId { get; set; }
      }

  
  
  

  Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
• • Reply
  

  mreyeros

  Contributor

  4022 Points

  736 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 02:31 PM|LINK

  UPDATE:

  Ok so I was testing and noticed that if I keep my code identical except I swap theHtml.DropdownListFor calls with Html.TextboxFor calls then the validation works. What could be causing this? Could it be a framework bug with the unobtrusive validation?

  Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
• • Reply
  

  raduenuca

  All-Star

  24675 Points

  4250 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 02:47 PM|LINK

  How is the html for the select (dropdownlist) and textbox (for the m => m.CustomerVehicles[i].VehicleMakeId) generated?

  Please click 'Mark as Answer' if my reply has assisted you
  
  Radu Enuca | Blog
• • Reply
  

  counsellorbe...

  Member

  540 Points

  112 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 03:24 PM|LINK

  mreyeros

  Ok so I was testing and noticed that if I keep my code identical except I swap theHtml.DropdownListFor calls with Html.TextboxFor calls then the validation works. What could be causing this? Could it be a framework bug with the unobtrusive validation?

   

  Michael,

  Yes, this is a bug in unobtrusive validation of dropdownlists.  MVC 3 RTM does not create unobtrusive validation for a collection of dropdownlists.  See http://aspnet.codeplex.com/workitem/7629.  The problem is that the code to build the unobtrusive validation makes a call WITHOUT reference to the metadata, which causes it to return a null value.  The solution is to build your own HtmlHelper for DropDownListFor (I call mine DdUovFor), and in the helper, make the following call:

  IDictionary<string, object> validationAttributes = htmlHelper
                  .GetUnobtrusiveValidationAttributes(ExpressionHelper.GetExpressionText(expression), metadata);

  Then, you can combine the IDictionary with any other htmlAttributes, and pass the result to SelectExtensions.DropDownListFor(), and you will receive back a dropdownlist with the unobtrusive validation rules.

  counsellorben

  
   

   

  • Marked as answer by mreyeros on Feb 04, 2011 01:51 AM
• • Reply
  

  mreyeros

  Contributor

  4022 Points

  736 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 04:06 PM|LINK

  Good afternoon counsellorben could you please provide me with a sample of how your helper is defined. It would be greatly appreciated.

  Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
• • Reply
  

  counsellorbe...

  Member

  540 Points

  112 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 04:47 PM|LINK

  Michael,

  OK, you asked for it, you got it.  Below is the code for my helpers:

  [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
          public static MvcHtmlString DdUovFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList)
          {
              return DdUovFor(htmlHelper, expression, selectList, null /* optionLabel */, null /* htmlAttributes */);
          }
  
  
          [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
          public static MvcHtmlString DdUovFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, object htmlAttributes)
          {
              return DdUovFor(htmlHelper, expression, selectList, null /* optionLabel */, new RouteValueDictionary(htmlAttributes));
          }
  
  
          [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
          public static MvcHtmlString DdUovFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, IDictionary<string, object> htmlAttributes)
          {
              return DdUovFor(htmlHelper, expression, selectList, null /* optionLabel */, htmlAttributes);
          }
  
  
          [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
          public static MvcHtmlString DdUovFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string optionLabel)
          {
              return DdUovFor(htmlHelper, expression, selectList, optionLabel, null /* htmlAttributes */);
          }
  
  
          [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
          public static MvcHtmlString DdUovFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string optionLabel, object htmlAttributes)
          {
              return DdUovFor(htmlHelper, expression, selectList, optionLabel, new RouteValueDictionary(htmlAttributes));
          }
  
  
          [SuppressMessage("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters", Justification = "Users cannot use anonymous methods with the LambdaExpression type")]
          [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
          public static MvcHtmlString DdUovFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string optionLabel, IDictionary<string, object> htmlAttributes)
          {
              if (expression == null)
              {
                  throw new ArgumentNullException("expression");
              }
  
  
              ModelMetadata metadata = ModelMetadata.From_L_a_m_b_d_a_E_x_p_r_e_s_s_i_o_n(expression, htmlHelper.ViewData);
  
  
              IDictionary<string, object> validationAttributes = htmlHelper
                  .GetUnobtrusiveValidationAttributes(ExpressionHelper.GetExpressionText(expression), metadata);
  
  
              if (htmlAttributes == null)
                  htmlAttributes = validationAttributes;
              else
                  htmlAttributes = htmlAttributes.Concat(validationAttributes).ToDictionary(k => k.Key, v => v.Value);
  
  
              return SelectExtensions.DropDownListFor(htmlHelper, expression, selectList, optionLabel, htmlAttributes);
          }

  Also, in the web.config file in the Views folder, be sure to add the namespace which covers your HtmlHelper class, in the following section:

    <system.web.webPages.razor>
      <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
      <pages pageBaseType="System.Web.Mvc.WebViewPage">
        <namespaces>
          <add namespace="YOUR NAMESPACE HERE" />
  

  
  counsellorben
   

  • Edited by counsellorben on Feb 03, 2011 04:53 PM
  • Edited by counsellorben on Feb 03, 2011 04:55 PM
• • Reply
  

  mreyeros

  Contributor

  4022 Points

  736 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 04:53 PM|LINK

  Thank you very much counsellorben I will try to add this to my project and see how it works.  If you notice there was a piece of the code that was blocked.  Could you please forward me the code sample to my email mreyerosATgmail.com.

  
  

  Thank you again.

  Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
• • Reply
  

  counsellorbe...

  Member

  540 Points

  112 Posts

  Re: MVC 3 dropdownlist validation not working for complex view model

  Feb 03, 2011 04:57 PM|LINK

  mreyeros

  If you notice there was a piece of the code that was blocked.  

   

  Michael,

  I edited my post, and added underbars to the blocked line.  It is now visible, and all you need to do is remove the underbar characters.

  counsellorben