WPF Extensibility Hacks or WEX - Includes EventTrigger, ReactiveTrigger, InvokeMethodAction, InvokeCommandAction etc.

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Wex.Lib.Composition;

namespace Wex.Lib.Interactions
{
    public class ReactiveTrigger : ObserverTrigger<EventResult>
    {

        public string ImportName
        {
            get { return (string)GetValue(ImportNameProperty); }
            set { SetValue(ImportNameProperty, value); }
        }

        // Using a DependencyProperty as the backing store for ImportName.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ImportNameProperty =
            DependencyProperty.Register("ImportName", typeof(string), typeof(ReactiveTrigger), new PropertyMetadata(string.Empty));


        /// <summary>
        /// Initialize this reactive trigger
        /// </summary>
        protected override void Initialize()
        {
            this.Cleanup();
            var func = WexPartComposer.Resolve(this.ImportName);
            if (func == null) throw new InvalidOperationException("The requested reactive trigger name is not found in the exported collection");
            this.Observable = func(this.Source);
        }

        /// <summary>
        /// On next action for this observer trigger
        /// </summary>
        /// <param name="param"></param>
        protected override void OnNext(object param)
        {
            this.Dispatcher.BeginInvoke(new Action<EventResult>(InvokeConditional), new object[] { param as EventResult });
        }

    }
}