private async Task DoActivity(ActivityFlowStep activityFlowStep, FlowContext stepFlowContext,
FlowValues flowValues, FlowTrace flowTrace, CancellationToken cancellationToken)
{
var activityRequest = CreateRequest(stepFlowContext, activityFlowStep, flowValues);
if (IsRequestDisabled(activityRequest))
{
_logger?.LogActivityRequestDisabled(stepFlowContext, activityRequest);
return;
}
_logger?.LogActivityRequest(stepFlowContext, activityRequest);
var stopWatch = new Stopwatch();
stopWatch.Start();
object activityResponse =
await GetActivityResponse(
stepFlowContext, activityFlowStep, activityRequest, cancellationToken);
stopWatch.Stop();
ValidateFlowObjectValues(activityResponse, activityResponse.GetType().GetFlowObjectType(), activityFlowStep.Name);
flowTrace.AddStep(new FlowTraceStep {
StepType = FlowTraceStepType.Activity, Name = activityFlowStep.Name
});
_logger?.LogActivityResponse(stepFlowContext, activityResponse, stopWatch.ElapsedMilliseconds);
SetFlowValuesFromResponse(activityFlowStep.Definition, stepFlowContext, flowValues, activityRequest, activityResponse);
AppendResponseFlowTrace(flowTrace, activityResponse);
}
private void RecordLabelStep(FlowTrace flowTrace, FlowContext stepFlowContext)
{
_logger.LogLabel(stepFlowContext);
flowTrace.AddStep(new FlowTraceStep {
StepType = FlowTraceStepType.Label, Name = stepFlowContext.FlowStepName
});
}
public async Task <TFlowResponse> Handle(TFlowRequest flowRequest, CancellationToken cancellationToken)
{
// TODO: Respect the cancellation token
var flowContext = new FlowContext(typeof(TFlowRequest), flowRequest.FlowContext);
try
{
var stopWatch = new Stopwatch();
stopWatch.Start();
using (flowContext.IsRootFlow ? _logger?.BeginFlowScope(flowContext) : null)
{
_logger?.LogFlowRequest(flowContext, flowRequest);
var flowDefinition = ResolveFlowDefinition(flowRequest, flowContext);
var flowValues = GetInitialFlowValues(flowDefinition, flowRequest);
var flowTrace = new FlowTrace();
var flowStepIndex = 0;
while (flowStepIndex < flowDefinition.Steps.Count)
{
var flowStep = flowDefinition.Steps[flowStepIndex];
var stepFlowContext = flowContext.GetStepContext(flowStep.Name);
OnDebugEvent(flowStep.Name, FlowDebugEvent.PreStep, flowValues);
flowStepIndex =
await PerformFlowStep(
stepFlowContext, flowDefinition, flowStep, flowStepIndex, flowValues, flowTrace, cancellationToken);
OnDebugEvent(flowStep.Name, FlowDebugEvent.PostStep, flowValues);
}
var flowResponse = BuildFlowResponse(flowContext, flowDefinition, flowTrace, flowValues);
stopWatch.Stop();
_logger?.LogFlowResponse(flowContext, flowResponse, stopWatch.ElapsedMilliseconds);
return(flowResponse);
}
}
catch (Exception ex) when(LogFlowError(flowContext, flowRequest, ex))
{
throw;
}
}
private static TFlowResponse BuildFlowResponse(FlowContext flowContext, FlowDefinition <TFlowRequest, TFlowResponse> flowDefinition,
FlowTrace flowTrace, FlowValues flowValues)
{
var flowResponseType = typeof(TFlowResponse);
var flowResponse = (TFlowResponse)Activator.CreateInstance(flowResponseType);
var flowObjectType = flowResponseType.GetFlowObjectType();
var missingMandatoryPropertyNames = new List <string>();
foreach (var flowObjectProperty in flowObjectType.Properties)
{
var binding =
flowDefinition.Finalizer?.Inputs.Find(b => b.Property.Name == flowObjectProperty.Name)
?? new FlowValueInputBinding(flowObjectProperty)
{
FlowValueSelector = new FlowValueSingleSelector(flowObjectProperty.Name)
};
if (binding.TryGetRequestValue(flowValues, flowResponse, out var responseValue))
{
flowObjectProperty.PropertyInfo.SetValue(flowResponse, responseValue);
}
CheckMandatoryFlowObjectProperty(flowResponse, flowObjectProperty, missingMandatoryPropertyNames);
}
if (missingMandatoryPropertyNames.Count > 0)
{
throw new FlowException(
$"The following mandatory properties were not populated on {flowResponseType.FullName}: " +
$"{string.Join(", ", missingMandatoryPropertyNames.ToArray())}");
}
if (flowResponse is FlowResponse baseFlowResponse)
{
baseFlowResponse.CorrelationId = flowContext.CorrelationId;
baseFlowResponse.RequestId = flowContext.RequestId;
baseFlowResponse.FlowInstanceId = flowContext.FlowInstanceId;
baseFlowResponse.Trace = flowTrace;
}
return(flowResponse);
}
private static void AppendResponseFlowTrace(FlowTrace flowTrace, dynamic activityResponse)
{
var subFlowTrace = activityResponse is FlowResponse flowStepResponse ? flowStepResponse.Trace : null;
flowTrace.AddSubFlowTrace(subFlowTrace);
}
private int CheckDecision(int flowStepIndex, DecisionFlowStepBase decisionFlowStep, FlowDefinition <TFlowRequest, TFlowResponse> flowDefinition,
FlowContext stepFlowContext, FlowValues flowValues, FlowTrace flowTrace)
{
var decisionRequest = (FlowDecisionBase)CreateRequest(stepFlowContext, decisionFlowStep, flowValues);
// TODO: Pass the targets directly into GetMatchingBranchIndex
decisionFlowStep.Branches.ForEach(b => decisionRequest.AddBranch(b.Targets));
_logger?.LogDecisionRequest(stepFlowContext, decisionRequest);
var branchIndex = decisionRequest.GetMatchingBranchIndex();
if (branchIndex < 0 || branchIndex >= decisionFlowStep.Branches.Count)
{
throw new FlowException($"The branch index returned was out of bounds of the branch array: {branchIndex}");
}
var branch = decisionFlowStep.Branches[branchIndex];
flowTrace.AddStep(new FlowTraceStep
{
StepType = FlowTraceStepType.Decision, Name = decisionFlowStep.Name, BranchTargets = branch.Targets
});
_logger?.LogDecisionResponse(stepFlowContext, branch);
if (branch.IsEnd)
{
return(int.MaxValue);
}
if (branch.IsUnhandled)
{
throw new FlowUnhandledElseException($"Unhandled ELSE for decision '{decisionFlowStep.Name}'");
}
var isContinue = (branch.NextStepName == null);
if (isContinue)
{
return(flowStepIndex + 1);
}
var nextFlowStepIndex = flowDefinition.GetStepIndex(branch.NextStepName);
return(nextFlowStepIndex);
}
private async Task <int> PerformFlowStep(FlowContext stepFlowContext, FlowDefinition <TFlowRequest, TFlowResponse> flowDefinition, FlowStep flowStep,
int flowStepIndex, FlowValues flowValues, FlowTrace flowTrace, CancellationToken cancellationToken)
{
int nextFlowStepIndex;
switch (flowStep)
{
case ActivityFlowStep activityFlowStep:
await DoActivity(
activityFlowStep, stepFlowContext, flowValues,
flowTrace, cancellationToken);
nextFlowStepIndex = flowStepIndex + 1;
break;
case DecisionFlowStepBase decisionFlowStep:
nextFlowStepIndex =
CheckDecision(
flowStepIndex, decisionFlowStep, flowDefinition, stepFlowContext, flowValues,
flowTrace);
break;
case GotoFlowStep gotoFlowStep:
_logger.LogGoto(stepFlowContext, gotoFlowStep.NextStepName);
nextFlowStepIndex = flowDefinition.GetStepIndex(gotoFlowStep.NextStepName);
break;
case LabelFlowStep _:
RecordLabelStep(flowTrace, stepFlowContext);
nextFlowStepIndex = flowStepIndex + 1;
break;
case EndFlowStep _:
nextFlowStepIndex = int.MaxValue;
break;
default:
throw new FlowException(
$"Unexpected flow activityFlowStep type {flowStep.GetType().FullName}");
}
return(nextFlowStepIndex);
}
internal void AddSubFlowTrace(FlowTrace subFlowTrace)
{
_steps.Last().SubFlowTrace = subFlowTrace;
}