private Task InvokeHubPipeline(IHub hub,
IJsonValue[] parameterValues,
MethodDescriptor methodDescriptor,
HubRequest hubRequest,
StateChangeTracker tracker)
{
// TODO: Make adding parameters here pluggable? IValueProvider? ;)
HubInvocationProgress progress = GetProgressInstance(methodDescriptor, value => SendProgressUpdate(hub.Context.ConnectionId, tracker, value, hubRequest));
Task <object> piplineInvocation;
try
{
var args = _binder.ResolveMethodParameters(methodDescriptor, parameterValues);
// We need to add the IProgress<T> instance after resolving the method as the resolution
// itself looks for overload matches based on the incoming arg values
if (progress != null)
{
args = args.Concat(new [] { progress }).ToList();
}
var context = new HubInvokerContext(hub, tracker, methodDescriptor, args);
// Invoke the pipeline and save the task
piplineInvocation = _pipelineInvoker.Invoke(context);
}
catch (Exception ex)
{
piplineInvocation = TaskAsyncHelper.FromError <object>(ex);
}
// Determine if we have a faulted task or not and handle it appropriately.
return(piplineInvocation.ContinueWithPreservedCulture(task =>
{
if (progress != null)
{
// Stop ability to send any more progress updates
progress.SetComplete();
}
if (task.IsFaulted)
{
return ProcessResponse(tracker, result: null, request: hubRequest, error: task.Exception);
}
else if (task.IsCanceled)
{
return ProcessResponse(tracker, result: null, request: hubRequest, error: new OperationCanceledException());
}
else
{
return ProcessResponse(tracker, task.Result, hubRequest, error: null);
}
})
.FastUnwrap());
}
private static HubInvocationProgress GetProgressInstance(MethodDescriptor methodDescriptor, Func <object, Task> sendProgressFunc)
{
HubInvocationProgress progress = null;
if (methodDescriptor.ProgressReportingType != null)
{
progress = HubInvocationProgress.Create(methodDescriptor.ProgressReportingType, sendProgressFunc);
}
return(progress);
}