How can I test for [AllowHtml] attribute within an editor template?

Question

I would like to be able to test a property for the [AllowHtml] attribute from within an editor template.

It doesn't seem to be lurking within ViewData.ModelMetadata.

I've tried iterating through ViewData.ModelMetadata.AdditionalValues to see if it's there, but it doesn't appear to be.

I've scoured Google and Brad Wilson's post on templates, but I can't find the answer anywhere.

Answer 1

I believe you'll have to do some heavy lifting in the template like:

var allowHtmlAttribute = this.ViewData.ModelMetadata
  .ContainerType
  .GetProperty(this.ViewData.ModelMetadata.PropertyName)
  .GetCustomAttributes(typeof(AllowHtmlAttribute), false)
  .Select(a => a as AllowHtmlAttribute)
  .FirstOrDefault(a => a != null);

and now that I think about it, a Extension Method would be great!

public static class ModelMetadataExtensions
{
  public T GetPropertyAttribute<T>(this ModelMetadata instance)
    where T : Attribute
  {
    var result = instance.ContainerType
      .GetProperty(instance.PropertyName)
      .GetCustomAttributes(typeof(T), false)
      .Select(a => a as T)
      .FirstOrDefault(a => a != null);

    return result;
  } 
}

Then

var myAttribute = this.ViewData.ModelMetadata
  .GetPropertyAttribute<AllowHtmlAttribute>();