protected virtual async Task ExecuteMessageHandlerAsync(
EventArgs messageEventArgs,
ReceivedItemHandlerAsyncDelegate receivedItemHandlerAsyncDelegateFunc,
bool automaticFinalizationEnabled = true
)
{
messageEventArgs.AssertNotNull(nameof(messageEventArgs));
receivedItemHandlerAsyncDelegateFunc.AssertNotNull(nameof(receivedItemHandlerAsyncDelegateFunc));
AzureServiceBusReceivedItem <TUniqueIdentifier, TPayload> azureServiceBusReceivedItem = null;
//FIRST attempt to convert the Message into an AzureServiceBus Received Item....
try
{
//Initialize the MessageHandler facade for processing the Azure Service Bus message...
azureServiceBusReceivedItem = await CreateReceivedItemAsync(
messageEventArgs,
//Force Dead-lettering if there is any issue with initialization!
true
).AssertNotNull(nameof(azureServiceBusReceivedItem));
}
catch (Exception exc)
{
var messageException = new Exception("The message could not be correctly initialized due to unexpected exception." +
" It must be Dead lettered to prevent blocking of the Service Bus as it will never be" +
" processed successfully.", exc);
this.Options.ErrorHandlerCallback?.Invoke(messageException);
}
//IF the Received Item is successfully initialized then process it!
if (azureServiceBusReceivedItem != null)
{
try
{
//Execute the delegate to handle/process the published item...
await receivedItemHandlerAsyncDelegateFunc(azureServiceBusReceivedItem).ConfigureAwait(false);
//If necessary, we need to Finalize the item with Azure Service Bus (Complete/Abandon) based on the Status returned on the item!
if (automaticFinalizationEnabled && !azureServiceBusReceivedItem.IsStatusFinalized)
{
await azureServiceBusReceivedItem.SendFinalizedStatusToAzureServiceBusAsync().ConfigureAwait(false);
}
}
catch (Exception exc)
{
this.Options.ErrorHandlerCallback?.Invoke(exc);
//Always attempt to Reject/Abandon the message if any unhandled exceptions are thrown...
if (!azureServiceBusReceivedItem.IsStatusFinalized)
{
//Finalize the status as set by the Delegate function if it's not already Finalized!
//NOTE: We ALWAYS do this even if autoMessageFinalizationEnabled is false to prevent BLOCKING and risk of Infinite Loops...
await azureServiceBusReceivedItem.SendFinalizedStatusToAzureServiceBusAsync().ConfigureAwait(false);
}
}
}
}
protected virtual async Task <AzureServiceBusReceivedItem <TUniqueIdentifier, TPayload> > CreateReceivedItemAsync(
EventArgs baseMessageEventArgs,
bool deadLetterOnFailureToInitialize = false
)
{
AzureServiceBusReceivedItem <TUniqueIdentifier, TPayload> azureServiceBusReceivedItem = null;
var initializationErrorMessage = $"Unable to initialize {nameof(SqlTransactionalOutbox)} Received Item [{nameof(AzureServiceBusReceivedItem<TUniqueIdentifier, TPayload>)}]";
switch (baseMessageEventArgs)
{
case ProcessMessageEventArgs messageEventArgs:
try
{
azureServiceBusReceivedItem = new AzureServiceBusReceivedItem <TUniqueIdentifier, TPayload>(messageEventArgs, this.OutboxItemFactory);
}
catch (Exception exc)
{
if (deadLetterOnFailureToInitialize)
{
await messageEventArgs.DeadLetterMessageAsync(messageEventArgs.Message, initializationErrorMessage, exc.GetMessagesRecursively());
}
throw;
}
break;
case ProcessSessionMessageEventArgs sessionMessageEventArgs:
try
{
azureServiceBusReceivedItem = new AzureServiceBusReceivedItem <TUniqueIdentifier, TPayload>(sessionMessageEventArgs, this.OutboxItemFactory);
}
catch (Exception exc)
{
if (deadLetterOnFailureToInitialize)
{
await sessionMessageEventArgs.DeadLetterMessageAsync(sessionMessageEventArgs.Message, initializationErrorMessage, exc.GetMessagesRecursively());
}
throw;
}
break;
}
return(azureServiceBusReceivedItem);
}