in .net mvc4 how to exclude dropdown from unobtrusive validation

Question

I have optional dropdown and it triggers validation errors if selection not made, how do I make it optional but still bind it if selection is made.

got this answer link but it actually stops binding, that is not what I want, also I know how to get rid of unobtrusive validation completely and get it done classic way and then get what I want from http post but I want to know if mvc4 client validation is flexible for this. Basically I am validating server side and throwing exceptions then adding them to ModelState, so kind of need partial support from mvc built-in client validation and it works fine except for dropdowns.

my model has no "Required" attributes on properties and here is my form:

    @using (Html.BeginForm("Send", "Mail", FormMethod.Post))
    {
        @Html.AntiForgeryToken()
        @Html.ValidationSummary()
        <fieldset>
            <legend>New Support Ticket: </legend>
            <ul>
                <li>
                    <label for="@Model.TypeLookupId">Type</label>
                    @Html.DropDownListFor(m => m.TypeLookupId, Model.Types)
                </li>
                <li>
                    <label for="@Model.IssueName">Subject</label>
                    @Html.TextBoxFor(m => m.IssueName, Model.IssueName)
                </li>  

                <li>
                    <label for="@Model.IssueNewNote">Comment</label>
                    @Html.TextAreaFor(m => m.IssueNewNote, string.Empty)
                </li>

                <li>
                    <input type="file" name="files" id="files" multiple="multiple"/>
                </li>


                <li>
                    <input type="submit" value="Save" />
                </li>


            </ul>

        </fieldset>
    }

Answer 1

int are not nullable by default. Validation will treat this as required. Change your property to int? or Nullable<int> to make it not required.