How to read property data annotation value in .NET MVC

Question

I Just starting out w/ ASP.NET MVC 3 and I am trying to render out the following HTML for the string properties on a ViewModel on the create/edit view.

Answer 1

A full code sample for tvanfosson's answer:

Model:

public class Product
{
    public int Id { get; set; }

    [MaxLength(200)]
    public string Name { get; set; }

EditorTemplates\String.cshtml

@model System.String
@{
    var metadata = ViewData.ModelMetadata;
    var prop = metadata.ContainerType.GetProperty(metadata.PropertyName);
    var attrs = prop.GetCustomAttributes(false);

    var maxLength = attrs.OfType().FirstOrDefault();
}

Editor Template:

@model System.String
@using System.ComponentModel.DataAnnotations;
@using Brass9.Web.Mvc.EditorTemplateHelpers;
@{
    var metadata = ViewData.ModelMetadata;

    var attrs = EditorTemplateHelper.GenerateAttributes(ViewData, new Delegate[] {
        new Func(len => "maxlength=" + len.MaximumLength),
        new Func(max => "maxlength=" + max.Length)
    });

    if (metadata.IsRequired)
    {
        attrs.Add("required");
    }

    string attrsHtml = String.Join(" ", attrs);
}

So you pass in an array of Delegates, and for each entry use a Func, and then return whatever HTML string you wanted for each attribute.

This actually decouples well - you can map only the attributes you care about, you can map different sets for different parts of the same HTML, and the final usage (like @attrsHtml) doesn't harm readability of the template.