Question

I am using MVC 3 with Razor. I can’t figure out how to code a string extension regex to take this:

This_is_some_text

to display:

This is some text

I set up some enums for a drop down list, so they appear thusly (obviously I can’t create an enum with a space):

public enum MyProperty 
{
     This_is_some_text, 
     This_is_some_other_text
}

I just cannot figure out the regex is to do what I want if I am doing this:

 public static string EnumToDisplay(this string str)
        {
            return Regex.Replace(str, "[What is the regex I should use?]");
        }

As a bonus for me I would also like to add a period “.” to the end of the enum. The reason for this is that I have OCD and my enums are taking the form of short sentences. 🙂

Thanks!

Answer 1

Why do you want to use regular expressions? A very wise man once said, I quote:

Some people, when confronted with a problem, think “I know, I’ll use
regular expressions.” Now they have two problems.

How about using the [Display] attribute which is kinda designed exactly for this purpose:

public enum MyProperty
{
    [Display(Name = "This is some super text")]
    This_is_some_text,

    [Display(Name = "And this is some other text")]
    This_is_some_other_text
}

and then writing a custom Html helper:

public static class HtmlExtensions
{
    public static IHtmlString DisplayForEnum<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression)
    {
        if (!typeof(TProperty).IsEnum)
        {
            throw new ArgumentException("sorry this helper is inteded to be used with enum types");
        }

        var model = htmlHelper.ViewData.Model;

        if (htmlHelper.ViewData.Model == null)
        {
            return MvcHtmlString.Empty;
        }


        var field = typeof(TProperty).GetField(expression.Compile()(htmlHelper.ViewData.Model).ToString());
        if (field == null)
        {
            return new HtmlString(htmlHelper.Encode(htmlHelper.ViewData.Model.ToString()));
        }

        var display = field.GetCustomAttributes(typeof(DisplayAttribute), true).FirstOrDefault() as DisplayAttribute;
        if (display == null)
        {
            return new HtmlString(htmlHelper.Encode(htmlHelper.ViewData.Model.ToString()));
        }

        return new HtmlString(htmlHelper.Encode(display.Name));
    }
}

So now assuming you have a view model:

public class MyViewModel
{
    public MyProperty Foo { get; set; }
}

and a controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var model = new MyViewModel
        {
            Foo = MyProperty.This_is_some_other_text
        };
        return View(model);
    }
}

you could use the custom helper we just wrote in the view to display a user friendly text that we might have associated to an ugly enum. Hey, now you could even have this working with globalization and multiple languages using resources:

@model MyViewModel
@Html.DisplayForEnum(x => x.Foo)