public virtual async Task <RunWorkflowResult> RunWorkflowAsync(
IWorkflowBlueprint workflowBlueprint,
WorkflowInstance workflowInstance,
string?activityId = default,
object?input = default,
CancellationToken cancellationToken = default)
{
using var loggingScope = _logger.BeginScope(new Dictionary <string, object> { ["WorkflowInstanceId"] = workflowInstance.Id });
using var workflowExecutionScope = _serviceScopeFactory.CreateScope();
var workflowExecutionContext = new WorkflowExecutionContext(workflowExecutionScope.ServiceProvider, workflowBlueprint, workflowInstance, input);
if (!string.IsNullOrWhiteSpace(workflowInstance.ContextId))
{
var loadContext = new LoadWorkflowContext(workflowExecutionContext);
workflowExecutionContext.WorkflowContext = await _workflowContextManager.LoadContext(loadContext, cancellationToken);
}
// If the workflow instance has a CurrentActivity, it means the workflow instance is being retried.
var currentActivity = workflowInstance.CurrentActivity;
if (currentActivity != null)
{
activityId = currentActivity.ActivityId;
}
var activity = activityId != null?workflowBlueprint.GetActivity(activityId) : default;
// Give application a chance to prevent workflow from executing.
var validateWorkflowExecution = new ValidateWorkflowExecution(workflowExecutionContext, activity);
await _mediator.Publish(validateWorkflowExecution, cancellationToken);
if (!validateWorkflowExecution.CanExecuteWorkflow)
{
_logger.LogInformation("Workflow execution prevented for workflow {WorkflowInstanceId}", workflowInstance.Id);
return(new RunWorkflowResult(workflowInstance, activityId, false));
}
await _mediator.Publish(new WorkflowExecuting(workflowExecutionContext), cancellationToken);
RunWorkflowResult runWorkflowResult;
switch (workflowExecutionContext.Status)
{
case WorkflowStatus.Idle:
runWorkflowResult = await BeginWorkflow(workflowExecutionContext, activity, cancellationToken);
if (!runWorkflowResult.Executed)
{
_logger.LogDebug("Workflow {WorkflowInstanceId} cannot begin from an idle state (perhaps it needs a specific input)", workflowInstance.Id);
return(runWorkflowResult);
}
break;
case WorkflowStatus.Running:
await RunWorkflowAsync(workflowExecutionContext, cancellationToken);
runWorkflowResult = new RunWorkflowResult(workflowInstance, activityId, true);
break;
case WorkflowStatus.Suspended:
runWorkflowResult = await ResumeWorkflowAsync(workflowExecutionContext, activity !, cancellationToken);
if (!runWorkflowResult.Executed)
{
_logger.LogDebug("Workflow {WorkflowInstanceId} cannot be resumed from a suspended state (perhaps it needs a specific input)", workflowInstance.Id);
return(runWorkflowResult);
}
break;
default:
throw new ArgumentOutOfRangeException();
}
await _mediator.Publish(new WorkflowExecuted(workflowExecutionContext), cancellationToken);
var statusEvent = workflowExecutionContext.Status switch
{
WorkflowStatus.Cancelled => new WorkflowCancelled(workflowExecutionContext),
WorkflowStatus.Finished => new WorkflowCompleted(workflowExecutionContext),
WorkflowStatus.Faulted => new WorkflowFaulted(workflowExecutionContext),
WorkflowStatus.Suspended => new WorkflowSuspended(workflowExecutionContext),
_ => default(INotification)
};
if (statusEvent != null)
{
_logger.LogTrace("Publishing a status event of type {EventType} for workflow {WorkflowInstanceId}", statusEvent.GetType().Name, workflowInstance.Id);
await _mediator.Publish(statusEvent, cancellationToken);
}
await _mediator.Publish(new WorkflowExecutionFinished(workflowExecutionContext), cancellationToken);
return(runWorkflowResult);
}
protected virtual async Task <RunWorkflowResult> RunWorkflowInternalAsync(WorkflowExecutionContext workflowExecutionContext, string?activityId = default, CancellationToken cancellationToken = default)
{
var workflowInstance = workflowExecutionContext.WorkflowInstance;
if (!string.IsNullOrWhiteSpace(workflowInstance.ContextId))
{
var loadContext = new LoadWorkflowContext(workflowExecutionContext);
workflowExecutionContext.WorkflowContext = await _workflowContextManager.LoadContext(loadContext, cancellationToken);
}
// If the workflow instance has a CurrentActivity, it means the workflow instance is being retried.
var currentActivity = workflowInstance.CurrentActivity;
if (activityId == null && currentActivity != null)
{
activityId = currentActivity.ActivityId;
}
var workflowBlueprint = workflowExecutionContext.WorkflowBlueprint;
var activity = activityId != null?workflowBlueprint.GetActivity(activityId) : default;
// Give application a chance to prevent workflow from executing.
var validateWorkflowExecution = new ValidateWorkflowExecution(workflowExecutionContext, activity);
await _mediator.Publish(validateWorkflowExecution, cancellationToken);
if (!validateWorkflowExecution.CanExecuteWorkflow)
{
_logger.LogInformation("Workflow execution prevented for workflow {WorkflowInstanceId}", workflowInstance.Id);
return(new RunWorkflowResult(workflowInstance, activityId, null, false));
}
await _mediator.Publish(new WorkflowExecuting(workflowExecutionContext), cancellationToken);
RunWorkflowResult runWorkflowResult;
switch (workflowExecutionContext.Status)
{
case WorkflowStatus.Idle:
runWorkflowResult = await BeginWorkflow(workflowExecutionContext, activity, cancellationToken);
if (!runWorkflowResult.Executed)
{
if (workflowInstance.WorkflowStatus != WorkflowStatus.Faulted)
{
_logger.LogDebug("Workflow {WorkflowInstanceId} cannot begin from an idle state (perhaps it needs a specific input)", workflowInstance.Id);
return(runWorkflowResult);
}
}
break;
case WorkflowStatus.Running:
runWorkflowResult = await RunWorkflowAsync(workflowExecutionContext, activity, cancellationToken);
break;
case WorkflowStatus.Suspended:
runWorkflowResult = await ResumeWorkflowAsync(workflowExecutionContext, activity !, cancellationToken);
if (!runWorkflowResult.Executed)
{
_logger.LogDebug("Workflow {WorkflowInstanceId} cannot be resumed from a suspended state (perhaps it needs a specific input)", workflowInstance.Id);
return(runWorkflowResult);
}
break;
default:
throw new ArgumentOutOfRangeException();
}
await _mediator.Publish(new WorkflowExecuted(workflowExecutionContext), cancellationToken);
var statusEvents = workflowExecutionContext.Status switch
{
WorkflowStatus.Cancelled => new INotification[] { new WorkflowCancelled(workflowExecutionContext), new WorkflowInstanceCancelled(workflowInstance) },
WorkflowStatus.Finished => new INotification[] { new WorkflowCompleted(workflowExecutionContext) },
WorkflowStatus.Faulted => new INotification[] { new WorkflowFaulted(workflowExecutionContext) },
WorkflowStatus.Suspended => new INotification[] { new WorkflowSuspended(workflowExecutionContext) },
_ => Array.Empty <INotification>()
};
foreach (var statusEvent in statusEvents)
{
await _mediator.Publish(statusEvent, cancellationToken);
}
await _mediator.Publish(new WorkflowExecutionFinished(workflowExecutionContext), cancellationToken);
return(runWorkflowResult);
}