public override void Handle(IMessage msg, string processor)
{
using (var scope = Container.BeginLifetimeScope())
{
dynamic saga = HandlerInvoker.InstantiateHandler(scope);
var correlationId = saga.GetCorrelationId(msg as IEvent);
dynamic sagaState = scope.Resolve(SagaStateType);
this.LogDebug($"Message '{msg}' started new saga {SagaStateType}");
saga.Data = sagaState;
HandlerInvoker.HandleMessage(msg, saga, processor);
try
{
SaveSagaState(sagaState, scope, correlationId, true);
}
catch (SagaExistsException)
{
this.LogInfo($"Saga '{SagaStateType.FullName}' already exists. We leave it there");
}
}
}
/**Add a route to the list of routes.
* @param id The RouteID
* @param type The pattern type to use
* @param pattern The route pattern to match to
* @param handler A lambda(or similar) to invoke a new HttpHandler, such as ()=>{return new MyHandler;}
*/
public void AddRoute(string id, PatternTypes type, string pattern, HandlerInvoker handler)
{
var r = new Route {
Pattern = pattern, Handler = handler, PatternType = type, ID = id
};
Routes.Add(r);
}
/**Add a route to the list of routes.
* @param id The RouteID
* @param type The pattern type to use
* @param pattern The route pattern to match to
* @param handler A lambda(or similar) to invoke a new HttpHandler, such as ()=>{return new MyHandler;}
*/
static public void AddRoute(string id, PatternTypes type, string pattern, HandlerInvoker handler)
{
/**TODO: This needs to be smart enough so that routes can not be added while routes are being parsed, else get a
* "collection modified" exception from .Net. **/
if (router == null)
{
router = new Router();
}
router.AddRoute(id, type, pattern, handler);
}
async Task TryMountSagaDataOnInvoker(HandlerInvoker sagaInvoker, object body, string label, List <RelevantSagaInfo> loadedSagaData, List <RelevantSagaInfo> newlyCreatedSagaData, ITransactionContext transactionContext)
{
var foundExistingSagaData = false;
var correlationProperties = _sagaHelper.GetCorrelationProperties(body, sagaInvoker.Saga);
var correlationPropertiesRelevantForMessage = correlationProperties.ForMessage(body).ToArray();
foreach (var correlationProperty in correlationPropertiesRelevantForMessage)
{
var valueFromMessage = correlationProperty.ValueFromMessage(new MessageContext(transactionContext), body);
var sagaData = await _sagaStorage.Find(sagaInvoker.Saga.GetSagaDataType(), correlationProperty.PropertyName, valueFromMessage);
if (sagaData == null)
{
continue;
}
sagaInvoker.SetSagaData(sagaData);
foundExistingSagaData = true;
loadedSagaData.Add(new RelevantSagaInfo(sagaData, correlationProperties, sagaInvoker.Saga));
_log.Debug("Found existing saga data with ID {sagaDataId} for message {messageLabel}", sagaData.Id, label);
break;
}
if (!foundExistingSagaData)
{
var messageType = body.GetType();
var canBeInitiatedByThisMessageType = sagaInvoker.CanBeInitiatedBy(messageType);
if (canBeInitiatedByThisMessageType)
{
var newSagaData = _sagaHelper.CreateNewSagaData(sagaInvoker.Saga);
// if there's exacly one correlation property that points to a property on the saga data, we can set it
if (correlationPropertiesRelevantForMessage.Length == 1)
{
TrySetCorrelationPropertyValue(newSagaData, correlationPropertiesRelevantForMessage[0], body, transactionContext);
}
sagaInvoker.SetSagaData(newSagaData);
_log.Debug("Created new saga data with ID {sagaDataId} for message {messageLabel}", newSagaData.Id, label);
newlyCreatedSagaData.Add(new RelevantSagaInfo(newSagaData, correlationProperties, sagaInvoker.Saga));
}
else
{
_log.Debug("Could not find existing saga data for message {messageLabel}", label);
sagaInvoker.SkipInvocation();
}
}
}
public async Task HandlerInvokerTest()
{
//ARRANGE
var result = 0;
var command = new TestCommand(Guid.NewGuid(), Guid.NewGuid());
var handler = new TestCommandHandler(() => result = 10);
var handlerInvoker = new HandlerInvoker();
//ACT
await handlerInvoker.InvokeHandlers(new[] { handler }, command);
//ASSERT
Assert.AreEqual(10, result);
}
public async Task Single_Handler_Can_Be_Invoked()
{
//ARRANGE
var result = 0;
var logger = new Mock <IGWLogger <BaseMessageHandler <TestMessage> > >();
var command = new TestMessage(Guid.NewGuid(), Guid.NewGuid());
var handler = new TestMessageHandler(() => result = 10, logger.Object, false);
var handlerInvoker = new HandlerInvoker();
//ACT
await handlerInvoker.InvokeHandlers(new[] { handler }, command, CancellationToken.None);
//ASSERT
Assert.That(result, Is.EqualTo(10));
}
public void If_Handler_Is_Null_Argument_Null_Exception_Is_Thrown()
{
//ARRANGE
var command = new TestMessage(Guid.NewGuid(), Guid.NewGuid());
var handlerInvoker = new HandlerInvoker();
//ACT
async Task Del()
{
await handlerInvoker.InvokeHandlers(null, command, CancellationToken.None);
}
//ASSERT
Assert.That(Del, Throws.ArgumentNullException);
}
async Task TryMountSagaDataOnInvoker(HandlerInvoker sagaInvoker, object body, string label, List <RelevantSagaInfo> loadedSagaData, List <RelevantSagaInfo> newlyCreatedSagaData)
{
var foundExistingSagaData = false;
var correlationProperties = _sagaHelper.GetCorrelationProperties(body, sagaInvoker.Saga);
var correlationPropertiesRelevantForMessage = correlationProperties.ForMessage(body);
foreach (var correlationProperty in correlationPropertiesRelevantForMessage)
{
var valueFromMessage = correlationProperty.ValueFromMessage(body);
var sagaData =
await
_sagaStorage.Find(sagaInvoker.Saga.GetSagaDataType(), correlationProperty.PropertyName, valueFromMessage);
if (sagaData == null)
{
continue;
}
sagaInvoker.SetSagaData(sagaData);
foundExistingSagaData = true;
loadedSagaData.Add(new RelevantSagaInfo(sagaData, correlationProperties, sagaInvoker.Saga));
_log.Debug("Found existing saga data with ID {0} for message {1}", sagaData.Id, label);
break;
}
if (!foundExistingSagaData)
{
var messageType = body.GetType();
var canBeInitiatedByThisMessageType = sagaInvoker.CanBeInitiatedBy(messageType);
if (canBeInitiatedByThisMessageType)
{
var newSagaData = _sagaHelper.CreateNewSagaData(sagaInvoker.Saga);
sagaInvoker.SetSagaData(newSagaData);
_log.Debug("Created new saga data with ID {0} for message {1}", newSagaData.Id, label);
newlyCreatedSagaData.Add(new RelevantSagaInfo(newSagaData, correlationProperties, sagaInvoker.Saga));
}
else
{
_log.Debug("Could not find existing saga data for message {0}", label);
sagaInvoker.SkipInvocation();
}
}
}
public async Task HandlerInvokerTest()
{
//ARRANGE
var result = 0;
var command = new TestCommand(Guid.NewGuid(), Guid.NewGuid());
var handler = new TestCommandHandler(() => result = 10);
var handlerInvoker = new HandlerInvoker();
var serialised = JsonConvert.SerializeObject(command, command.GetType(), new JsonSerializerSettings {
TypeNameHandling = TypeNameHandling.Objects
});
var deserialised = JsonConvert.DeserializeObject(serialised, new JsonSerializerSettings {
TypeNameHandling = TypeNameHandling.Objects
});
//ACT
await handlerInvoker.InvokeHandlers(new[] { handler }, (object)deserialised);
//ASSERT
Assert.AreEqual(10, result);
}
public async Task Setup()
{
exampleEventMappedTypeName = FullNameTypeMap.Instance.GetNameForType(typeof(ExampleEvent));
var services = new ServiceCollection();
services.AddSingleton(mockHandler);
serviceProvider = services.BuildServiceProvider();
behaviour = new HandlerInvoker(
mockMessageSource.Object,
services,
FullNameTypeMap.Instance,
"EndpointName",
Mock.Of <IOutgoingPipeline>());
await behaviour
.Initialise(CancellationToken.None)
.ConfigureAwait(false);
}
Muliple_Exceptions_Thrown_Within_Handlers_The_Exceptions_Will_Bubble_Though_To_Invoker_As_An_Aggreated_Exception()
{
//ARRANGE
var logger = new Mock <IGWLogger <BaseMessageHandler <TestMessage> > >();
const string errorMessage = "Hello World! I am an error message";
var command = new TestMessage(Guid.NewGuid(), Guid.NewGuid());
var handler1 = new TestMessageHandler(() => throw new Exception(errorMessage), logger.Object, false);
var handler2 = new TestMessageHandler(() => throw new Exception(errorMessage), logger.Object, false);
var handlerInvoker = new HandlerInvoker();
//ACT
try
{
await handlerInvoker.InvokeHandlers(new object[] { handler1, handler2 }, command, CancellationToken.None);
}
catch (AggregateException ae)
{
//ASSERT
Assert.That(ae.InnerExceptions.Count, Is.EqualTo(2));
}
}
public async Task Exception_Thrown_Within_Handler_The_Exception_Will_Bubble_Though_To_Invoker()
{
//ARRANGE
var logger = new Mock <IGWLogger <BaseMessageHandler <TestMessage> > >();
const string errorMessage = "Hello World! I am an error message";
var command = new TestMessage(Guid.NewGuid(), Guid.NewGuid());
var handler = new TestMessageHandler(() => throw new Exception(errorMessage), logger.Object, false);
var handlerInvoker = new HandlerInvoker();
//ACT
try
{
await handlerInvoker.InvokeHandlers(new[] { handler }, command, CancellationToken.None);
}
catch (AggregateException ae)
{
//ASSERT
var exception = ae.InnerExceptions.First();
Assert.That(exception, Is.TypeOf <Exception>());
Assert.That(exception.Message, Is.EqualTo(errorMessage));
}
}
internal HandlerInvokerWrapper(HandlerInvoker handlerInvokerImplementation, string messageType)
{
_handlerInvokerImplementation = handlerInvokerImplementation;
_messageType = messageType;
}
