FooBarClassCompletion.cs

[HtmlCompletionProvider(CompletionTypes.Values,"*", "class")]
[ContentType(HtmlContentTypeDefinition.HtmlContentType)]
class FooBarClassCompletion : BaseCompletionProvider
{
        private static List<string> _classes = new List<string>()
        {
            "foo",
            "bar",
        };

        public override string CompletionType
        {
            get { return CompletionTypes.Values; }
        }

        public override  IList<HtmlCompletion> GetEntries(HtmlCompletionContext context)
        {
            var list = new List<HtmlCompletion>();

            foreach (var name in _classes)
            {
                list.Add(CreateItem(name, context.Session));
            }

            return list;
        }
}

abstract class BaseCompletionProvider : IHtmlCompletionListProvider
{

        public abstract string CompletionType { get; }

        public abstract IList<HtmlCompletion> GetEntries(HtmlCompletionContext context);

        protected HtmlCompletion CreateItem(string name, ICompletionSession session)
        {
            return new HtmlCompletion(name, name, "", null, null, session);
        }
}