Question

This validation should work, but the post fires right past it if there are no selected values in the dropdown. When moved to another non-partial the validation works just fine. Edited for brevity.

ViewModel:

public class BuilderVM
{
    [Display(Name = "Select A Task")]
    [Required]
    public int? TaskId { get; set; }
    public GenericSelectList Tasks { get; set; }
}

Parent View (the partial view is rendered at the bottom of this page after a post. as you may have noticed, the ajax options dictate that the partial view will be rendered in div id="MoveOn"):

@{
 ViewBag.Title = "Builder";
 AjaxOptions ajaxOpts = new AjaxOptions
 {
    LoadingElementDuration = 2,
    LoadingElementId = "removeChoice",
    UpdateTargetId = "MoveOn"
 };
}
<div id="removeChoice">
@using (Ajax.BeginForm("Selected", ajaxOpts))
{
<fieldset>
    <div>
     //Data For Submission (This data validates perfectly before post)
    </div>
    <p><input type="submit" value="Go" /></p>
</fieldset>
}
</div>
<div id="MoveOn"></div>

Partial View (rendered after a post from parent view):

@model namespace.BuilderVM
@{
 AjaxOptions ajaxOpts = new AjaxOptions
  {
    UpdateTargetId = "Entry",
    LoadingElementDuration = 2,
    LoadingElementId = "RemoveEntry"
  };
}

<div id="RemoveEntry">
<h2>Details</h2>
@using (Ajax.BeginForm("Data", ajaxOpts))
{
@Html.ValidationSummary(true)
<fieldset>
<legend>Data</legend>
<div>
    <span class="label">@Html.LabelFor(model => model.TaskId)</span>
    <span class="content">
    @Html.DropDownListFor(
        model => model.TaskId,
        new SelectList(
            Model.Tasks.Values,
            "Id",
            "DisplayFields",
            Model.Tasks.StartValue
        ),
        Model.Tasks.Message
    )
    </span>@Html.ValidationMessageFor(model => model.TaskId)
</div>
<p><input type="submit" value="Add Work Completed Data" /></p>
</fieldset>
}
</div>
<div id="Entry"></div>

Although the dropdownlistfor is bound to model.TaskId which is annotated with [Required] when the post button is clicked (input type="submit") and there is no value selected in the dropdownlist the post goes through instead of stopping and appending the validation message. I am not sure what to do to fix this, as it works just fine when copy pasted to a regular view. Why wont the partial view validation work?

Answer 1

The problem is that the validator just loads in the beginning (with $(document).ready()).
What you can do is the following (insert in the partial view):

    <script>
        $(function() {
            $.validator.unobtrusive.parse('.Content');
        });
    </script>

From the given information I assume this is your problem. Hope this helps you.