I'm enjoying workflow emmensely, I particularly like that we're forced to code in a manner that has us focus on the concerns of the Activity's Use Case.
For example the TagProcessorActivity and ElementProcessorActivity represented below:
Each of the above activities (pointed to by arrows) have a CodeActivity, SetCurrentElementCode and HtmlTagCode respectively; these code activities have a sole purpose in life. The HtmlTag's purpose is to update/set the MAMLTag property to the value returned by the ProcessorService (service is set in SequenceActivityBase via Unity container).
The TagProcessorActivity (executes first) has the sole responsibility of setting the current element; the ReplicatorActivity provides us a CurrentIndex to notify us of our position in the Replicator list. The TagProcessorActivity uses a method on our DataState object (of type IMAMLState) to update our state object; an excerpt from the MAMLState class follows:
/// <summary>
/// Sets the current element.
/// </summary>
/// <param name="activity">The activity.</param>
/// <returns></returns>
public ElementEnt SetCurrentElement(Activity activity)
{
if (activity == null || activity.Parent ==null)
return null;
if (!(activity.Parent.Parent != null
&& activity.Parent.Parent is ReplicatorActivity))
return null;
ReplicatorActivity grandParent =
activity.Parent.Parent as ReplicatorActivity;
ElementBeingProcessed = grandParent.CurrentIndex;
CurrentElement = (ElementEnt)
grandParent.InitialChildData[grandParent.CurrentIndex];
return CurrentElement;
}
Note: the [Sequence]ActivityBase is responsible for setting up the Activity so that the state is available; an excerpt from the ActivityBase follows:
protected override void OnActivityExecutionContextLoad(IServiceProvider provider)
{
IWFState<IMAMLState> State;
base.OnActivityExecutionContextLoad(provider);
State = provider
.GetService(typeof(IWFState<IMAMLState>)) as IWFState<IMAMLState>;
Logger = State.UnityContainer.Resolve<ILoggerFacade>();
ProcessorService = State.UnityContainer.Resolve<ITagProcessorService>();
DataState = State.Data;
WireupActivity(this);
}
At each level of processing there is a clear, testable separation of concern.
Source code available at http://www.Codeplex.com/MAMLConverter
Tags:
unity,
workflow
Categories:
Unity