How can I make the Required attribute for my custom DropDownList editor template operate client side?

Question

I have an editor template for DropDownLists that is marked with an attribute like this:

[AttributeUsage(AttributeTargets.Property)]
public class DropDownListAttribute : UIHintAttribute
{
    public string SelectListName { get; set; }
    public DropDownListAttribute(string selectListName)
        : base("DropDownList", "MVC", selectListName)
    {
        SelectListName = selectListName;
    }
}

And itself looks like this:

@using Comair.RI.UI.Core
@{
    var list = this.GetModelSelectList();
    var listWithSelected = new SelectList(list.Items, list.DataValueField, list.DataTextField, Model);
}
@Html.DropDownListFor(m => Model, listWithSelected, " - select - ")

My issue here is it only validates server side, which is very annoying for a user to resolve all client side validations, only to submit and get a new, surprise server side validation.

@SławomirRosiek What is that supposed to mean? This is a general question applies to any model. — ProfK, Jan 17 '13 at 17:35
For me it works - did you have problem only with that control or maybe with all client-side validators? — Sławomir Rosiek, Jan 17 '13 at 17:55

Sławomir Rosiek · Answer 1 · 2013-01-18T18:44:13.410

If your client side validation doesn't work it may be caused by one of the following reasons:

Your web.config doesn't have that enteries:

&ltappSettings>
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>

You forgotten to add validation scripts:

<script src="@Url.Content("~/Scripts/jquery.validate.min.js")"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")"></script>

Your controls are not surrounded by Html.BeginForm or Ajax.BeginForm
Client-side validation can stop working in EditorFor after update to ASP.NET MVC 4 if you use:
```
@Html.DropDownListFor(m => Model, listWithSelected, " - select - ")
```
Replacing Model with m should resolve problem:
```
@Html.DropDownListFor(m => m, listWithSelected, " - select - ")
```

All my other client side validation works. My problem is that only my `DropDownList` editor template doesn't validate client side. — ProfK, Jan 18 '13 at 02:35

score 0 · Answer 2 · edited May 23 '17 at 12:05

0

Set the required class

@Html.DropDownListFor(m => Model, listWithSelected, " - select - ", new { @class='required' })

See ASP MVC 3: How can I do Client side Validation on a Select List?

edited May 23 '17 at 12:05

Community

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answered Jan 18 '13 at 11:15

Jeroen K

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Lovely, except the default message is just "This field is required." not the "The {0} field is required." Find if you place validation messages inline, but not so cool if you group them in some 'window' somewhere. – ProfK Jan 19 '13 at 16:29

How can I make the Required attribute for my custom DropDownList editor template operate client side?

2 Answers2