/// <inheritdoc />
public async Task <object> Execute(WorkflowInstanceState state, CancellationToken token)
{
object result = await node.Execute(state, token);
if (operation != null)
{
if (result != null)
{
if (!state.Variables.TryGetValue(VariableName, out object lhs))
{
lhs = result is string? "" : Activator.CreateInstance(result.GetType());
}
result = await operation.ExecuteAsync(new VariableProvider(state.Variables, new Variable("lhs", lhs), new Variable("rhs", result)), token);
}
}
state.Variables[VariableName] = result;
return(result);
}
async Task <object> Execute(WorkflowInstanceState state, CancellationToken token, IInstanceNode current, object lastresult = null)
{
while (current != null)
{
try {
if (state.Profiling)
{
Stopwatch stopwatch = Stopwatch.StartNew();
lastresult = await current.Execute(state, token);
state.Logger.Performance(state.Workflow, current.NodeId, current.NodeName, stopwatch.Elapsed);
}
else
{
lastresult = await current.Execute(state, token);
}
if (token.IsCancellationRequested)
{
throw new TaskCanceledException();
}
// used for workflow suspension
if (lastresult is SuspendState)
{
return(lastresult);
}
}
catch (Exception e) {
state.Logger.Warning($"Error while executing node '{current.NodeName}'", e.Message);
InstanceTransition next = await EvaluateTransitions(current, state.Logger, new VariableProvider(state.Variables, new Variable("error", e)), current.ErrorTransitions, token);
if (next == null)
{
throw;
}
current = next.Target;
continue;
}
try {
InstanceTransition transition;
if (lastresult is LoopCommand)
{
if (current.LoopTransitions.Count == 0)
{
throw new InvalidOperationException("Iterator node without any loop transitions detected.");
}
transition = await EvaluateTransitions(current, state.Logger, state.Variables, current.LoopTransitions, token);
current = transition?.Target ?? current;
}
else
{
transition = await EvaluateTransitions(current, state.Logger, state.Variables, current.Transitions, token);
current = transition?.Target;
}
}
catch (Exception e) {
state.Logger.Warning($"Error while evaluating transitions of node '{current?.NodeName}'", e.Message);
InstanceTransition next = await EvaluateTransitions(current, state.Logger, new VariableProvider(state.Variables, new Variable("error", e)), current?.ErrorTransitions, token);
if (next == null)
{
throw;
}
current = next.Target;
}
}
return(lastresult);
}
public static Task <object> Execute(IInstanceNode node, IDictionary <string, object> variables = null)
{
variables ??= new Dictionary <string, object>();
return(node.Execute(new WorkflowInstanceState(new WorkflowIdentifier(), new WorkableLogger(new NullLogger <NodeTest>(), new WorkableTask()), new StateVariableProvider(variables), s => null, null, null, false), CancellationToken.None));
}
