private object GetTaskContinuationFromMethodInvocation_Terse(IMethodInvocation methodInvocation, Action <Exception> exceptionHandler)
{
if (methodInvocation.Method.ReturnType.IsGenericType && methodInvocation.Method.ReturnType.GetGenericTypeDefinition() == typeof(Task <>))
{
var faultedTaskContinuationWrapper = new FaultedTaskContinuationWrapper(exceptionHandler);
var argumentType = methodInvocation.Method.ReturnType.GetGenericArguments().Single();
return(methodInvocation.Method.ReturnType
.GetMethods().Where(m => m.Name == "ContinueWith" && m.ReturnType.IsGenericType && m.GetParameters().Count() == 1)
.Single(m => m.GetParameters().Single().ParameterType.GetGenericArguments().First() == methodInvocation.Method.ReturnType)
.MakeGenericMethod(argumentType)
.Invoke(
methodInvocation.ReturnValue,
typeof(Func <,>).MakeGenericType(methodInvocation.Method.ReturnType, argumentType).CreateDelegate(
faultedTaskContinuationWrapper,
faultedTaskContinuationWrapper.GetType().GetMethod("ContinuationFunction").MakeGenericMethod(argumentType))));
}
else
{
var task = (Task)methodInvocation.ReturnValue;
return(task.ContinueWith(t => {
if (t.IsFaulted)
{
exceptionHandler(t.Exception);
}
}));
}
}
public object GetTaskContinuationFromMethodInvocation(IMethodInvocation methodInvocation, Action <Exception> exceptionHandler)
{
object taskContinuation = null;
var taskType = methodInvocation.ReturnValue.GetType();
/*
* act on this method only if it is generic and of type Task<TResult> for some TResult
*/
if (taskType.IsGenericType && taskType.GetGenericTypeDefinition() == typeof(Task <>))
{
/*
* the faultedTaskContinuationWrapper will PROVIDE AND EXPOSE the method that will be used as a continuation,
* in which will invoke the wrapped exceptionHandler.
*/
var faultedTaskContinuationWrapper = new FaultedTaskContinuationWrapper(exceptionHandler);
//-- the TResult
var resultType = taskType.GetGenericArguments().Single();
//-- this gets all the methods named "ContinueWith" that return a generic type (presumably Task<T>) and take a single argument
var continueWithMethods = taskType.GetMethods().Where(m => m.Name == "ContinueWith" && m.ReturnType.IsGenericType && m.GetParameters().Count() == 1);
//-- this gets the one that takes a Func<Task<T>, R> argument
var continueWithMethod = continueWithMethods.Single(m => m.GetParameters().Single().ParameterType.GetGenericArguments().First() == taskType);
// construct the actual (closed generic) method based on the above generic definition that will be invoked
var closedGenericContinueWithMethod = continueWithMethod.MakeGenericMethod(resultType);
var continuationMethod = typeof(Func <,>).MakeGenericType(taskType, resultType).CreateDelegate(
faultedTaskContinuationWrapper,
faultedTaskContinuationWrapper.GetType().GetMethod("ContinuationMethod").MakeGenericMethod(resultType));
// invoke the "ContinueWith" with method on the original task
taskContinuation = closedGenericContinueWithMethod.Invoke(methodInvocation.ReturnValue, continuationMethod);
}
else
{
var task = (Task)methodInvocation.ReturnValue;
return(task.ContinueWith(t => {
if (t.IsFaulted)
{
exceptionHandler(t.Exception);
}
}));
}
return(taskContinuation);
}
