public async Task <CommandResult <TResult> > DispatchAsync <TResult>(ICommand <TResult> command, CancellationToken cancellationToken)
{
await new SynchronizationContextRemover();
ICommandDispatchContext dispatchContext = _commandScopeManager.Enter();
try
{
CommandResult <TResult> dispatchResult = null;
CommandResult wrappedDispatchResult = null;
ICommandExecuter executer = null;
ICommandDispatcher dispatcher = null;
ICommand unwrappedCommand = command;
if (command is NoResultCommandWrapper wrappedCommand)
{
unwrappedCommand = wrappedCommand.Command;
}
// we specifically audit BEFORE dispatch as this allows us to capture intent and a replay to
// occur even if dispatch fails
// (there is also an audit opportunity after execution completes and I'm considering putting one in
// on dispatch success)
await _auditor.AuditPreDispatch(unwrappedCommand, dispatchContext, cancellationToken);
try
{
Stopwatch stopwatch = _collectMetrics ? Stopwatch.StartNew() : null;
Func <ICommandDispatcher> dispatcherFunc = _commandRegistry.GetCommandDispatcherFactory(command);
if (dispatcherFunc != null)
{
dispatcher = dispatcherFunc();
if (command != unwrappedCommand)
{
wrappedDispatchResult = await dispatcher.DispatchAsync(unwrappedCommand, cancellationToken);
}
else
{
dispatchResult = await dispatcher.DispatchAsync(command, cancellationToken);
}
executer = dispatcher.AssociatedExecuter;
}
await _auditor.AuditPostDispatch(unwrappedCommand, dispatchContext, stopwatch?.ElapsedMilliseconds ?? -1, cancellationToken);
if ((dispatchResult != null && dispatchResult.DeferExecution) || (wrappedDispatchResult != null && wrappedDispatchResult.DeferExecution))
{
return(new CommandResult <TResult>(default(TResult), true));
}
}
catch (Exception ex)
{
throw new CommandDispatchException(unwrappedCommand, dispatchContext.Copy(), dispatcher?.GetType() ?? GetType(), "Error occurred during command dispatch", ex);
}
if (executer == null)
{
executer = AssociatedExecuter;
}
return(new CommandResult <TResult>(await executer.ExecuteAsync(command, cancellationToken), false));
}
finally
{
_commandScopeManager.Exit();
}
}
public Task <bool> HandleException <TResult>(Exception ex, object handler, int handlerExecutionIndex, ICommand <TResult> command, ICommandDispatchContext dispatchContext)
{
throw new CommandExecutionException(command, handler?.GetType(), handlerExecutionIndex, dispatchContext?.Copy(), "Error occurred during command execution", ex);
}