DomainEvents

DomainEvents.cs

	///<summary>
	/// Provides methods for raising domaing events and registering their handlers.
	///</summary>
	public static class DomainEvents
	{
		[ThreadStatic]
		private static List<Delegate> actions;

		/// <summary>
		/// Gets or sets the service provider used to resolve event handlers.
		/// </summary>
		public static IServiceProvider ServiceProvider { get; set; }

		/// <summary>
		/// Associates a callback with a domain event.
		/// </summary>
		/// <typeparam name="T">The type of event the action should be triggered for.</typeparam>
		/// <param name="callback">The action to call when the specified event is raised.</param>
		public static ActionRegistration Register<T>(Action<T> callback) where T : IDomainEvent
		{
			if (actions == null) actions = new List<Delegate>();
            
			actions.Add(callback);

			return new ActionRegistration(actions, callback);
		}

		public static ActionRegistration Register<THandler, TEvent>(THandler handler)
			where TEvent : IDomainEvent
			where THandler : IDomainEventHandler<TEvent>
		{
			return Register<TEvent>(handler.Handle);
		}

		/// <summary>
		/// Clear all previously registere call back actions.
		/// </summary>
		public static void ClearCallbacks()
		{
			actions = null;
		}

		/// <summary>
		/// Raises a domain event.
		/// </summary>
		/// <typeparam name="T">The type of event to raise.</typeparam>
		/// <param name="args">The domain event to raise.</param>
		public static void Raise<T>(T args) where T : IDomainEvent
		{
			if (ServiceProvider != null)
				foreach (var handler in ServiceProvider.GetServices<IDomainEventHandler<T>>()) 
					handler.Handle(args);

			if (actions != null)
				foreach (var action in actions)
					if (action is Action<T>) ((Action<T>)action)(args);
		}
	}