Ditto TypeConverter - Multiple IEnumerable<IPublishedContent> & Single IPublishedContent

MultipleIPublishedTypeConverterBase.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using Umbraco.Core;
using Umbraco.Core.Models;

namespace My.Website.ComponentModel.TypeConverters
{
    public abstract class MultipleIPublishedContentTypeConverterBase<T> : TypeConverter
    {
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            return sourceType.Implements<IEnumerable<IPublishedContent>>();
        }

        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            if (value is IEnumerable<IPublishedContent>)
            {
                return ConvertFromMultipleIPublishedContent(value as IEnumerable<IPublishedContent>);
            }
            return base.ConvertFrom(context, culture, value);
        }

        protected abstract T ConvertFromMultipleIPublishedContent(IEnumerable<IPublishedContent> entities);
    }
}

MyViewModel.cs

using Our.Umbraco.Ditto;
using System.ComponentModel;
using My.Website.ComponentModel.TypeConverters;

namespace My.Website.ViewModels
{
    public class MyViewModel
    {
        [UmbracoProperty("targetSearchPagePickedFromTheCmsAsIdLikeMyAuthorsToChooseWhereTheWebsiteHeaderSearchFormPostsToForTheirSearchResults")]
        [TypeConverter(typeof(SinglePublishedContentUrlTypeConverter))]
        public string FormUrl { get; set; }
    }
}

SingleIPublishedContentTypeConverterBase.cs

using System.Collections.Generic;
using System.Linq;
using Umbraco.Core.Models;

namespace My.Website.ComponentModel.TypeConverters
{
    public abstract class SingleIPublishedContentTypeConverterBase<T> : MultipleIPublishedContentTypeConverterBase<T>
    {
        protected override T ConvertFromMultipleIPublishedContent(IEnumerable<IPublishedContent> entities)
        {
            var firstItem = entities.FirstOrDefault();

            if (firstItem != null)
            {
                return ConvertFromSingleIPublishedContent(firstItem);
            }

            return default(T);
        }

        public abstract T ConvertFromSingleIPublishedContent(IPublishedContent entity);
    }
}

SinglePublishedContentUrlTypeConverter.cs

using Umbraco.Core.Models;

namespace My.Website.ComponentModel.TypeConverters
{
    public class SinglePublishedContentUrlTypeConverter : SingleIPublishedContentTypeConverterBase<string>
    {
        public override string ConvertFromSingleIPublishedContent(IPublishedContent entity) {        
            return entity.Url;
        }
    }
}