/// <summary>
/// Runs this instance.
/// </summary>
public override void Run()
{
Trace.WriteLine("Starting processing of messages");
// Initiates the message pump and callback is invoked for each message that is received, calling close on the client will stop the pump.
this.Client.OnMessage(
receivedMessage =>
{
try
{
this.resetEvent = new ManualResetEvent(false);
// Process the message
Trace.WriteLine(
"Processing Service Bus message: " + receivedMessage.SequenceNumber.ToString());
// Name of workflow to trigger.
var workflowToTrigger = receivedMessage.Properties["workflowName"];
// Prepare input message for Workflow.
var channelData = new ChannelData {
Payload = receivedMessage.GetBody <HostQueueMessage>()
};
this.arrivedMessage = channelData.Payload;
// You can save the workflow xaml externally (usually database). See this.
var workflowXaml = File.ReadAllText($"{workflowToTrigger}.txt");
if (!string.IsNullOrWhiteSpace(workflowXaml))
{
//// 5. Compose WF Application.
var workflowApplication =
new WorkflowApplication(
Routines.CreateWorkflowActivityFromXaml(workflowXaml, this.GetType().Assembly),
new Dictionary <string, object> {
{ "ChannelData", channelData }
});
//// 6. Extract Request Identifier to set it as identifier of workflow.
this.SetupWorkflowEnvironment(
workflowApplication,
channelData.Payload.WorkflowIdentifier);
//// 7. Test whether this is a resumed bookmark or a fresh message.
if (channelData.Payload.IsBookmark)
{
//// 8.1. Make sure there is data for this request identifier in storage to avoid errors due to transient errors.
if (null
!= this.repository.GetById(
"WorkflowInstanceStoreData",
channelData.Payload.WorkflowIdentifier.ToString()))
{
//// Prepare a new workflow instance as we need to resume bookmark.
var bookmarkedWorkflowApplication =
new WorkflowApplication(
Routines.CreateWorkflowActivityFromXaml(
workflowXaml,
this.GetType().Assembly));
this.SetupWorkflowEnvironment(
bookmarkedWorkflowApplication,
channelData.Payload.WorkflowIdentifier);
//// 9. Resume bookmark and supply input as is from channel data.
bookmarkedWorkflowApplication.Load(channelData.Payload.WorkflowIdentifier);
//// 9.1. If workflow got successfully completed, remove the host message.
if (BookmarkResumptionResult.Success
== bookmarkedWorkflowApplication.ResumeBookmark(
bookmarkedWorkflowApplication.GetBookmarks().Single().BookmarkName,
channelData,
TimeSpan.FromDays(7)))
{
Trace.Write(
Routines.FormatStringInvariantCulture("Bookmark successfully resumed."));
this.resetEvent.WaitOne();
this.Client.Complete(receivedMessage.LockToken);
return;
}
}
else
{
//// This was a transient error.
Trace.Write(Routines.FormatStringInvariantCulture("Error"));
}
}
//// 10. Run workflow in case of normal execution.
workflowApplication.Run(TimeSpan.FromDays(7));
Trace.Write(
Routines.FormatStringInvariantCulture(
"Workflow for request id has started execution"));
this.resetEvent.WaitOne();
}
}
catch
{
// Handle any message processing specific exceptions here
}
});
this.CompletedEvent.WaitOne();
}
