Override the ASP.NET MVC 3 Nullable Boolean EditorFor EditorTemplate

If you use EditorFor() in your MVC View code and pass it a nullable boolean (bool?), you'll see that MVC helpfully renders a tri-state dropdown list. However, the three choices in the dropdown are "Not Set", "True", and "False" which seem a bit unfriendly to some users.

Save the following template as Boolean.cshtml under Views / Shared / EditorTemplates in your project and you'll see a more friendly widget by default.

@model bool?
@using System.Web.Mvc

@{
    var selectList = new List<SelectListItem>();
    selectList.Add(new SelectListItem { Text = "", Value = "" });
    selectList.Add(new SelectListItem { Text = "Yes", Value = "true", Selected = Model.HasValue && Model.Value });
    selectList.Add(new SelectListItem { Text = "No", Value = "false", Selected = Model.HasValue && !Model.Value });
}

@Html.DropDownListFor(model => model, selectList)

Now you can customise it as you please.

If you don't want to override the standard template, bear in mind that you can save it with a different filename e.g. FriendlyBool.cshtml and then call it explicitly like so:

@Html.EditorFor(model => model.myNullableBool, "FriendlyBool")