I would expect a fluent method chain to not produce side effects when a method is invoked more than once.  particularly, concerning the ability to apply HtmlAttributes more than once to a method chain.  This prevents me from implementing meaningful extension methods to promote a DRY approach to views. 

In particular, I am trying to do something like this:

public static TextBoxBuilder<TProperty> PasswordFor<TModel, TProperty>(this WidgetFactory<TModel> widgetFactory, Expression<Func<TModel, TProperty>> expression)
        {
            return widgetFactory.TextBoxFor(expression).HtmlAttributes(new { type = "password" });
        }

        public static TextBoxBuilder<TModel> AutoFocus<TModel>(this TextBoxBuilder<TModel> builder)
        {
            return builder.HtmlAttributes(new { autofocus = true });
        }


I am finding that because the HTML attributes is cleared in your base implementation.. 

this.Component.HtmlAttributes.Clear();


it doesn't support an aggregation of attributes, but instead it's last-man-in.   that defeats the purpose of extensibility and effectively insists upon repetition and sort of brittle design that a copy/paste architecture results in.

I would believe it be completely acceptable to give the last-attribute-applied precedence and overwrite the value, but the reality is that we're talking about basic key/value pairs, and it shouldn't be difficult to merge the attributes as they are built.   best case, right now i have to implement my own derivation of the WidgetBuilderBase and implement an extension method off the WidgetFactory that bootstraps my functionality - certainly not a stretch, but more work than should probably be necessary.



   
    public virtual TBuilder HtmlAttributes(object attributes)
    {
      return this.HtmlAttributes(ObjectExtensions.ToDictionary(attributes));
    }

    public virtual TBuilder HtmlAttributes(IDictionary<string, object> attributes)
    {
      this.Component.HtmlAttributes.Clear();
      Kendo.Mvc.Extensions.DictionaryExtensions.Merge(this.Component.HtmlAttributes, attributes);
      return this as TBuilder;
    }