Get DataFormatString formatted value from server side

Question

class Report
{
    [Display(Name = "Market Value")]
    [DisplayFormat(DataFormatString = "£ {0:#,##0}", ConvertEmptyStringToNull = true)]
    public int? MarketValue { get; set; }
}

Of course it works in the view and the result is "£ 10,000"

@Html.DisplayFor(model => report.MarketValue)

How can I retrieve the formatted value via server side with something like this?

string formattedValue = report.MarketValue.ToFormattedString();

Thanks in advance!

Answer 1

Very rough, but it can do the thing:

public static string GetAttributeFormatedString<TModel, TMember>(this TModel model, Expression<Func<TModel, TMember>> memberSelector)
{
    var selectorBody = memberSelector.Body;
    if (selectorBody.NodeType != ExpressionType.MemberAccess)
    {
        throw new ArgumentException("Nope dude, not this time", "memberSelector");
    }
    var attribute = ((MemberExpression) selectorBody).Member
        .GetCustomAttributes(typeof(DisplayFormatAttribute), true)
        .OfType<DisplayFormatAttribute>()
        .FirstOrDefault();
    if (attribute == null)
    {
        throw new InvalidOperationException("Attribute, dude");
    }
    var format = attribute.DataFormatString;
    var result = string.Format(format, memberSelector.Compile().Invoke(model));

    return result;
}

Usage:

    var r = new Report
    {
        MarketValue = 10000
    };
    var formated = r.GetAttributeFormatedString(x => x.MarketValue);