How can I use DisplayName data annotations for column headers in WebGrid?

13
votes

I have a Car class that I'm trying to display in an MVC 3 view using the WebGrid helper. Below are the Car and it's metadata class.

Car class:

[MetadataType(typeof(CarMetadata))]
public partial class Car
{
    // car implementation
}

Car metadata class:

public class CarMetadata
{        
    [DisplayName("Car Name")]
    [StringLength(100, ErrorMessageResourceType = typeof(ValidationText), ErrorMessageResourceName="CarNameDescriptionLength")]
    [Required]
    public string CarName { get; set; }    
}

View contents:

@model List<Car>
...
var grid = new WebGrid(Model, canPage: true, rowsPerPage: 10);
grid.Pager(WebGridPagerModes.NextPrevious);

@grid.GetHtml(
    htmlAttributes: new { id = "grid" },
    columns: grid.Columns(
        grid.Column("CarName", ?????)
    ));

GOAL: I'd like to figure out how to use the DisplayName data annotation as the column header text in the WebGrid (?????). Does anyone know how this is accomplished?

Thanks in advance!

2
asp.netasp.net-mvc-3data-annotationswebgrid

2 Answers

11
votes

Ugly as hell but it could work:

grid.Column(
    "CarName", 
    ModelMetadata.FromLambdaExpression(
        car => car.CarName, 
        new ViewDataDictionary<Car>(new Car())
    ).DisplayName
)

The problem is that the WebGrid helper is entirely based on dynamic data, absolutely no strong typing and that's one of the reasons why I hate it. The WebMatrix team at Microsoft must be real fans of the C# 4.0 dynamic feature as their entire API takes only weakly typed objects :-)

MvcContrib Grid is much better.

0
votes

I have created a helper method like this:

public static string GetDisplayName<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> property)
{
    return GetDisplay(property);
}

public static string GetDisplayName<TModel, TProperty>(this HtmlHelper<IEnumerable<TModel>> html, Expression<Func<TModel, TProperty>> property)
{
    return GetDisplay(property);
}

private static string GetDisplay<M,P>(Expression<Func<M,P>> property)
{
    var propertyExp = (MemberExpression)property.Body;
    var member = propertyExp.Member;
    var disp = (DisplayAttribute)member.GetCustomAttribute(typeof(DisplayAttribute));
    if (disp == null)
    {
        return member.Name;
    }
    return disp.Name;
}

And used it like this:

new WebGridColumn { Header = Html.GetDisplayName(t=>t.Title), ColumnName = nameof(DataModel.Title), CanSort=true }