Question

We have a model with properties decorated with [Required] which works great for validation. However, what we’d like to do is mark those required fields in the view with an asterisk (or some other style) to denote they are required before the user enters any data for validation.

I don’t seem to be able to find anything built into the MVC framework to allow me to do this and therefore wondered if anyone else had already solved this and how?

Ultimately what we’re trying to prevent is the need to change code in two places if we subsequently remove a [Required] from a model property.

Many Thanks

Answer 1

You can build your own HtmlHelper extension for this:

public static string RequiredMarkFor<TModel, TValue>(this HtmlHelper html, Expression<Func<TModel, TValue>> expression)
{
    if(ModelMetadata.FromLambdaExpression(expression, html.ViewData).IsRequired)
         return "*";
    else
         return string.Empty;
}