private MethodInfo GetAvailabilityMethod(string?availabilityMethodName)
{
if (availabilityMethodName == null)
{
throw new Exception("If the action is conditionally available you need to provide a method to calculate availability.");
}
var declaringType = ActionMethod.DeclaringType;
var method = declaringType.GetMethod(availabilityMethodName);
if (method == null)
{
throw new Exception($"Availability Method {availabilityMethodName} was not found on type {declaringType.FullName}");
}
if (method.ReturnType != typeof(bool))
{
throw new Exception($"AvailabilityCheck method ({availabilityMethodName}) MUST return bool.");
}
var actionBindingParameterType = ActionMethod.GetParameters().First().ParameterType;
var methodParameters = method.GetParameters();
if (methodParameters.Count() != 1 || methodParameters.First().ParameterType != actionBindingParameterType)
{
throw new Exception($"AvailabilityCheck method was expected to have this signature 'bool {availabilityMethodName}({actionBindingParameterType.FullName})'");
}
return(method);
}
private static object[] CreateActionArguments(CliActionContext context)
{
var parameters = context.ActionRoute !.ActionMethod.GetParameters();
switch (parameters.Length)
{
case 0:
return(Array.Empty <object>());
case > 1:
throw new TargetParameterCountException("Action argument count must be 0 or 1");
default:
{
var option = new OptionParser(parameters.First().ParameterType).Parse(context.Arguments.ToArray());
return(new[] { option });
}
}
}
public override IAsyncResult BeginExecute(ControllerContext controllerContext, IDictionary <string, object> parameters, AsyncCallback callback, object state)
{
if (controllerContext == null)
{
throw new ArgumentNullException("controllerContext");
}
if (parameters == null)
{
throw new ArgumentNullException("parameters");
}
AsyncManager asyncHelper = GetAsyncManager(controllerContext.Controller);
SingleFireEvent setupCompletedEvent = new SingleFireEvent();
ContinuationListener listener = new ContinuationListener();
object theDelegate = null;
BeginInvokeCallback beginCallback = (innerCallback, innerState) => {
ManualAsyncResult asyncResult = new ManualAsyncResult()
{
AsyncState = innerState
};
// Get parameters for async setup method, then execute
ParameterInfo[] setupParametersInfos = ActionMethod.GetParameters();
var rawSetupParameterValues = from parameterInfo in setupParametersInfos
select ExtractParameterFromDictionary(parameterInfo, parameters, ActionMethod);
object[] setupParametersArray = rawSetupParameterValues.ToArray();
// to simplify the logic, force an asynchronous callback
asyncHelper.OutstandingOperations.Completed += delegate {
if (setupCompletedEvent.Signal())
{
listener.SetContinuation(() => {
ThreadPool.QueueUserWorkItem(o => {
asyncResult.MarkCompleted(false /* completedSynchronously */, innerCallback);
});
});
}
};
MethodDispatcher setupDispatcher = DispatcherCache.GetDispatcher(ActionMethod);
asyncHelper.OutstandingOperations.Increment();
object returnedDelegate = setupDispatcher.Execute(controllerContext.Controller, setupParametersArray);
ValidateDelegateNotNull(returnedDelegate, ActionMethod);
asyncHelper.OutstandingOperations.Decrement();
Thread.VolatileWrite(ref theDelegate, returnedDelegate);
listener.Signal();
return(asyncResult);
};
AsyncCallback <object> endCallback = ar => {
if (setupCompletedEvent.Signal())
{
// the setup method did not complete before this callback executed
throw new InvalidOperationException(MvcResources.AsyncActionDescriptor_EndExecuteCalledPrematurely);
}
object returnedDelegate = Thread.VolatileRead(ref theDelegate);
MethodInfo invokeMethod = returnedDelegate.GetType().GetMethod("Invoke", Type.EmptyTypes);
MethodDispatcher invokeDispatcher = DispatcherCache.GetDispatcher(invokeMethod);
object actionReturnValue = invokeDispatcher.Execute(returnedDelegate, _emptyParameters);
return(actionReturnValue);
};
// Set the timeout and go
int timeout = asyncHelper.Timeout;
return(AsyncResultWrapper.WrapWithTimeout(callback, state, beginCallback, endCallback, timeout, _executeTag));
}