public virtual T Then <T>(T nextTask, TaskRunOptions runOptions = TaskRunOptions.OnSuccess, bool taskIsTopOfChain = false)
where T : ITask
{
Guard.ArgumentNotNull(nextTask, nameof(nextTask));
var nextTaskBase = ((TaskBase)(object)nextTask);
// find the task at the top of the chain
if (!taskIsTopOfChain)
{
nextTaskBase = nextTaskBase.GetTopMostTask() ?? nextTaskBase;
}
// make the next task dependent on this one so it can get values from us
nextTaskBase.SetDependsOn(this);
var nextTaskFinallyHandler = nextTaskBase.finallyHandler;
if (runOptions == TaskRunOptions.OnSuccess)
{
this.continuationOnSuccess = nextTaskBase;
// if there are fault handlers in the chain we're appending, propagate them
// up this chain as well
if (nextTaskBase.continuationOnFailure != null)
{
SetFaultHandler(nextTaskBase.continuationOnFailure);
}
else if (nextTaskBase.continuationOnAlways != null)
{
SetFaultHandler(nextTaskBase.continuationOnAlways);
}
if (nextTaskBase.catchHandler != null)
{
Catch(nextTaskBase.catchHandler);
}
if (nextTaskFinallyHandler != null)
{
Finally(nextTaskFinallyHandler);
}
}
else if (runOptions == TaskRunOptions.OnFailure)
{
this.continuationOnFailure = nextTaskBase;
DependsOn?.Then(nextTaskBase, TaskRunOptions.OnFailure, true);
}
else
{
this.continuationOnAlways = nextTaskBase;
DependsOn?.SetFaultHandler(nextTaskBase);
}
// if the current task has a fault handler, attach it to the chain we're appending
if (finallyHandler != null)
{
TaskBase endOfChainTask = (TaskBase)nextTaskBase.GetEndOfChain();
while (endOfChainTask != this && endOfChainTask != null)
{
endOfChainTask.finallyHandler += finallyHandler;
endOfChainTask = endOfChainTask.DependsOn;
}
}
return(nextTask);
}