private static MethodInfo GetWorkerFactoryMapMethod(TypeMappedResponderWorkerFactory workerFactory)
{
return(workerFactory.GetType()
.GetMethods(BindingFlags.Public | BindingFlags.Instance)
.Single(x => x.Name == "Map" &&
x.IsGenericMethod &&
x.GetParameters().Count() == 1 &&
x.GetParameters().First().ParameterType.Name == typeof(Func <,>).Name));
}
public IResponderWorkerFactory Create <T>(T hub) where T : class
{
if (hub == null)
{
throw new ArgumentNullException("hub");
}
var methods = typeof(T)
.GetMethods(BindingFlags.Public | BindingFlags.Instance)
.Where(x => !x.IsGenericMethod)
.Where(x => typeof(IMessage).IsAssignableFrom(x.ReturnType))
.Where(x => x.GetParameters().Count() == 1 && typeof(IMessage).IsAssignableFrom(x.GetParameters().Single().ParameterType))
.ToList();
if (!methods.Any())
{
throw new ArgumentException("Hub instance has no worker methods that can be used to be bound " +
"(make sure methods with signature like Func<IMessage, IMessage> exist)");
}
var workerFactory = new TypeMappedResponderWorkerFactory();
var workerFactoryMapMethod = GetWorkerFactoryMapMethod(workerFactory);
MethodInfo defaultFuncMethod = null;
var alreadyMappedTypes = new Dictionary <Type, MethodInfo>();
foreach (var method in methods)
{
var inputType = method.GetParameters().Single().ParameterType;
var funcType = typeof(Func <,>).MakeGenericType(inputType, typeof(IMessage));
var func = Delegate.CreateDelegate(funcType, hub, method);
if (inputType == typeof(IMessage))
{
if (defaultFuncMethod != null)
{
throw new ArgumentException(
String.Format("Hub instance has multiple methods that are candidates for being a " +
"default responder ('{0}' and '{1}'). There must be only one such method.",
defaultFuncMethod.Name, method.Name));
}
defaultFuncMethod = method;
var defaultFunc = (Func <IMessage, IMessage>)func;
workerFactory.DefaultFunc = m => new ResponderWorker <IMessage>(defaultFunc);
}
else
{
MethodInfo alreadyMappedMethod;
if (alreadyMappedTypes.TryGetValue(inputType, out alreadyMappedMethod))
{
throw new ArgumentException(
String.Format("Hub instance has multiple methods that are candidates for being " +
"responder for input message type '{0}' (methods are: '{1}' and '{2}'). " +
"There must be only one method per input message type.",
inputType, alreadyMappedMethod.Name, method.Name));
}
alreadyMappedTypes[inputType] = method;
workerFactoryMapMethod.MakeGenericMethod(inputType).Invoke(workerFactory, new object[] { func });
}
}
return(workerFactory);
}
