Abstract workflow factory & example usage (SiteVisitWorkflow) for ObjectFlow

SiteVisitWorkflow.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using kpa.mko.dal;
using kpa.common.workflow;
using Rainbow.ObjectFlow.Stateful;
using kpa.common.container;
using kpa.common.interfaces;

namespace kpa.mko.bll.workflow
{
    public class SiteVisitWorkflow : WorkflowFactory<SiteVisit>
    {
        /// <summary>
        /// The key
        /// </summary>
        public const string WorkflowCode = "kpa.mko.SiteVisit.Approval";
        private static int? workflowFk;
        public static int WorkflowFk
        {
            get
            {
                if (!workflowFk.HasValue)
                    workflowFk = Workflow.GetByName(WorkflowCode).WorkflowId;
                return workflowFk.Value;
            }
        }

        protected override Rainbow.ObjectFlow.Stateful.IStatefulWorkflow<SiteVisit> Define()
        {
            return  new StatefulWorkflow<SiteVisit>(WorkflowFk)
                .Yield(WorkflowState.SiteVisit.Approvals.InProgress)
                .Yield(WorkflowState.SiteVisit.Approvals.District)
                .Yield(WorkflowState.SiteVisit.Approvals.Company)
                .Yield(WorkflowState.SiteVisit.Approvals.Finance);
        }
    }
}

WorkflowFactory.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Castle.DynamicProxy;
using Rainbow.ObjectFlow.Stateful;

namespace kpa.common.workflow
{
    /// <summary>
    /// Describes a workflow process or sub-process that an object can go through. Actual
    /// processes will descend from this class.
    /// </summary>
    public abstract class WorkflowFactory<T> : kpa.common.workflow.IWorkflowFactory<T>
        where T : class, IStatefulObject
    {
        private IStatefulWorkflow<T> workflow;

        /// <summary>
        /// This is where you define your workflow
        /// </summary>
        /// <remarks>We'll pass this a DP to record the steps that must happen and proxy
        /// the steps to an actual WorkFlow object. This way we have a full ordering built
        /// up in memory so we can easily jump steps and start part-way through."/></remarks>
        protected abstract IStatefulWorkflow<T> Define();

        /// <summary>
        /// For resuming a workflow that has already begun or starting a workflow on a new
        /// object.
        /// </summary>
        /// <param name="initializer"></param>
        /// <returns></returns>
        public virtual T Process(T initializer)
        {
            if (workflow == null)
                workflow = Define();
            return workflow.Start(initializer);
        }
    }
}