protected void AddResultHook <TBaseRequest, TResult>(IResultHook <TBaseRequest, TResult> hook)
{
if (!typeof(TBaseRequest).IsAssignableFrom(typeof(TRequest)))
{
throw new ContravarianceException(nameof(AddResultHook), typeof(TBaseRequest), typeof(TRequest));
}
ResultHooks.Add(InstanceResultHookFactory.From(hook));
}
internal static InstanceResultHookFactory From <TRequest, TResult>(
IResultHook <TRequest, TResult> hook)
{
return(new InstanceResultHookFactory(
hook,
new FunctionResultHook(typeof(TResult),
(request, result, ct) => hook
.Run((TRequest)request, (TResult)result, ct)
.ContinueWith(t => (object)t.Result))));
}
/// <summary>
/// Adds a result hook instance.
/// </summary>
public void AddResultHook(IResultHook hook)
{
var hookType = hook.GetType();
var baseHookType = hookType
.GetBaseTypes()
.SingleOrDefault(x =>
x.IsGenericType && x.GetGenericTypeDefinition() == typeof(ResultHook <,>));
if (baseHookType == null)
{
throw new ArgumentException($"Unable to add '{hookType}' as a result hook for '{typeof(TRequest)}'.\r\n" +
$"Result hooks must inherit ResultHook<TRequest, TResult>.");
}
var requestType = baseHookType.GenericTypeArguments[0];
if (!requestType.IsAssignableFrom(typeof(TRequest)))
{
throw new ContravarianceException(nameof(AddResultHook), requestType, typeof(TRequest));
}
var resultType = baseHookType.GenericTypeArguments[1];
var factoryMethod = typeof(InstanceResultHookFactory)
.GetMethod(nameof(InstanceResultHookFactory.From), BindingFlags.NonPublic | BindingFlags.Static)
.MakeGenericMethod(requestType, resultType);
try
{
AddResultHook((IResultHookFactory)factoryMethod.Invoke(null, new object[] { hook }));
}
catch (TargetInvocationException e)
{
if (e.InnerException != null)
{
throw e.InnerException;
}
throw e;
}
}
