public static CommandProcessingException Create(Command command, Exception caughtException)
{
var message = string.Format("An error occurred while processing command {0} - any events emitted will most likely not have been saved", command);
return new CommandProcessingException(message, caughtException)
{
FailedCommand = command
};
}
public Action<ICommandContext, Command> GetCommandAction(Command command)
{
if (command is ExecutableCommand)
{
return (context, executableCommand) => ((ExecutableCommand)executableCommand).Execute(context);
}
throw new ArgumentException(string.Format(@"Could not find a command mapping for the command {0} - please derive your command off of ExecutableCommand or the generic Command<TAggregateRoot>, or supply an action mapping when configuring the command processor by going .Options(o => o.AddCommandMappings(...))", command));
}
public CommandProcessingResult ProcessCommand(Command command)
{
if (!command.Meta.ContainsKey(DomainEvent.MetadataKeys.CommandTypeName))
{
var commandTypeName = _domainTypeNameMapper.GetName(command.GetType());
command.Meta[DomainEvent.MetadataKeys.CommandTypeName] = commandTypeName;
}
return _innerCommandProcessor.ProcessCommand(command);
}
public Action<ICommandContext, Command> GetCommandAction(Command command)
{
try
{
foreach (var mappings in _commandMappings)
{
var handler = mappings.GetHandlerFor(command);
if (handler != null) return handler;
}
return _defaultCommandMapper.GetCommandAction(command);
}
catch (Exception exception)
{
throw new ArgumentException(string.Format("Could not find command action to execute for command {0} - please add suitable command mappings on the TestContext like this: context.AddCommandMappings(...)", command), exception);
}
}
/// <summary>
/// Processes the specified command by invoking the generic eventDispatcher method
/// </summary>
public CommandProcessingResult ProcessCommand(Command command)
{
_logger.Debug("Processing command: {0}", command);
var emittedDomainEvents = new List<DomainEvent>();
try
{
var batchId = Guid.NewGuid();
_retryer.RetryOn<ConcurrencyException>(() =>
{
var unitOfWork = new RealUnitOfWork(_aggregateRootRepository, _domainTypeNameMapper);
var handler = _commandMapper.GetCommandAction(command);
handler(new DefaultCommandContext(unitOfWork, command.Meta), command);
var eventsFromThisUnitOfWork = unitOfWork.EmittedEvents.ToList();
// if command processing yielded no events, there's no more work to do
if (!eventsFromThisUnitOfWork.Any()) return;
// first: save the events
_logger.Debug("Saving batch {0} with {1} events", batchId, eventsFromThisUnitOfWork.Count);
var eventData = eventsFromThisUnitOfWork.Select(e => _domainEventSerializer.Serialize(e)).ToList();
_eventStore.Save(batchId, eventData);
unitOfWork.RaiseCommitted(eventsFromThisUnitOfWork);
emittedDomainEvents.AddRange(eventsFromThisUnitOfWork);
}, maxRetries: Options.MaxRetries);
}
catch (Exception exception)
{
// ordinary re-throw if exception is a domain exception
if (Options.DomainExceptionTypes.Contains(exception.GetType()))
{
throw;
}
throw CommandProcessingException.Create(command, exception);
}
try
{
_logger.Debug("Delivering {0} events to the dispatcher", emittedDomainEvents.Count);
// when we come to this place, we deliver the events to the view manager
_eventDispatcher.Dispatch(emittedDomainEvents);
}
catch (Exception exception)
{
var message =
string.Format(
"An error ocurred while dispatching events with global sequence numbers {0} to event dispatcher." +
" The events were properly saved in the event store, but you might need to re-initialize the" +
" event dispatcher",
string.Join(", ", emittedDomainEvents.Select(e => e.GetGlobalSequenceNumber())));
throw new ApplicationException(message, exception);
}
return emittedDomainEvents.Any()
? CommandProcessingResult.WithNewPosition(emittedDomainEvents.Max(e => e.GetGlobalSequenceNumber()))
: CommandProcessingResult.NoEvents();
}
IEnumerable<DomainEvent> InnerProcessCommand(RealUnitOfWork unitOfWork, Command command)
{
var handler = _commandMapper.GetCommandAction(command);
handler(new DefaultCommandContext(unitOfWork, command.Meta), command);
var emittedEvents = unitOfWork.EmittedEvents.ToList();
if (!emittedEvents.Any()) return emittedEvents;
return emittedEvents;
}
