public virtual void OnActivityExecuting(WorkflowContext workflowContext, ActivityContext activityContext, CancellationToken cancellationToken) {
}
public virtual void OnWorkflowResuming(WorkflowContext context, CancellationToken cancellationToken) {
}
private void ResumeWorkflow(AwaitingActivityRecord awaitingActivityRecord, WorkflowContext workflowContext, IDictionary<string, object> tokens) {
// signal every activity that the workflow is about to be resumed
var cancellationToken = new CancellationToken();
InvokeActivities(activity => activity.OnWorkflowResuming(workflowContext, cancellationToken));
if (cancellationToken.IsCancelled) {
// workflow is aborted
return;
}
// signal every activity that the workflow is resumed
InvokeActivities(activity => activity.OnWorkflowResumed(workflowContext));
var workflow = awaitingActivityRecord.WorkflowRecord;
workflowContext.Record = workflow;
workflow.AwaitingActivities.Remove(awaitingActivityRecord);
var blockedOn = ExecuteWorkflow(workflowContext, awaitingActivityRecord.ActivityRecord, tokens).ToList();
// is the workflow halted on a blocking activity, and there is no more awaiting activities
if (!blockedOn.Any() && !workflow.AwaitingActivities.Any()) {
// no, delete the workflow
_workflowRepository.Delete(awaitingActivityRecord.WorkflowRecord);
}
else {
// add the new ones
foreach (var blocking in blockedOn) {
workflow.AwaitingActivities.Add(new AwaitingActivityRecord {
ActivityRecord = blocking,
WorkflowRecord = workflow
});
}
}
}
public IEnumerable<ActivityRecord> ExecuteWorkflow(WorkflowContext workflowContext, ActivityRecord activityRecord, IDictionary<string, object> tokens) {
var firstPass = true;
var scheduled = new Stack<ActivityRecord>();
scheduled.Push(activityRecord);
var blocking = new List<ActivityRecord>();
while (scheduled.Any()) {
activityRecord = scheduled.Pop();
var activityContext = CreateActivityContext(activityRecord, tokens);
// while there is an activity to process
if (!firstPass){
if (activityContext.Activity.IsEvent) {
blocking.Add(activityRecord);
continue;
}
}
else {
firstPass = false;
}
// signal every activity that the activity is about to be executed
var cancellationToken = new CancellationToken();
InvokeActivities(activity => activity.OnActivityExecuting(workflowContext, activityContext, cancellationToken));
if (cancellationToken.IsCancelled) {
// activity is aborted
continue;
}
var outcomes = activityContext.Activity.Execute(workflowContext, activityContext).ToList();
// signal every activity that the activity is executed
InvokeActivities(activity => activity.OnActivityExecuted(workflowContext, activityContext));
foreach (var outcome in outcomes) {
// look for next activity in the graph
var transition = workflowContext.Record.WorkflowDefinitionRecord.TransitionRecords.FirstOrDefault(x => x.SourceActivityRecord == activityRecord && x.SourceEndpoint == outcome.TextHint);
if (transition != null) {
scheduled.Push(transition.DestinationActivityRecord);
}
}
}
// apply Distinct() as two paths could block on the same activity
return blocking.Distinct();
}
private void StartWorkflow(WorkflowContext workflowContext, ActivityRecord activityRecord, IDictionary<string, object> tokens) {
// signal every activity that the workflow is about to start
var cancellationToken = new CancellationToken();
InvokeActivities(activity => activity.OnWorkflowStarting(workflowContext, cancellationToken));
if (cancellationToken.IsCancelled) {
// workflow is aborted
return;
}
// signal every activity that the workflow is has started
InvokeActivities(activity => activity.OnWorkflowStarted(workflowContext));
var blockedOn = ExecuteWorkflow(workflowContext, activityRecord, tokens).ToList();
// is the workflow halted on a blocking activity ?
if (!blockedOn.Any()) {
// no, nothing to do
}
else {
// workflow halted, create a workflow state
_workflowRepository.Create(workflowContext.Record);
foreach (var blocking in blockedOn) {
workflowContext.Record.AwaitingActivities.Add(new AwaitingActivityRecord {
ActivityRecord = blocking,
WorkflowRecord = workflowContext.Record
});
}
}
}
