public CommandHandlerProvider(Type type, CommandHandlerActionDescriptor memberDescriptor)
{
if (type == null)
{
throw new ArgumentNullException(nameof(type));
}
_type = type;
_memberDescriptor = memberDescriptor;
}
public CommandHandlerInvoker(object handler, CommandHandlerActionDescriptor memberDescriptor, IServiceProvider serviceProvider)
{
if (handler == null)
{
throw new ArgumentNullException(nameof(handler));
}
if (serviceProvider == null)
{
throw new ArgumentNullException(nameof(serviceProvider));
}
_handler = handler;
_memberDescriptor = memberDescriptor;
_serviceProvider = serviceProvider;
}
private bool TryGetHandlingMember(MethodInfo member, out CommandHandlerActionDescriptor result)
{
var parameters = member.GetParameters();
if (parameters.Length == 0)
{
result = default;
return(false);
}
if (parameters.Any(p => p.ParameterType.IsByRef))
{
result = default;
return(false);
}
if (member.IsGenericMethod || member.IsGenericMethodDefinition)
{
result = default;
return(false);
}
if (member.IsDefined <NoCommandHandlerActionAttribute>())
{
result = default;
return(false);
}
var commandType = parameters[0].ParameterType;
var actionAttribute = member.GetCustomAttribute <CommandHandlerActionAttribute>();
if (actionAttribute != null && actionAttribute.CommandType != null)
{
if (!commandType.IsAssignableFrom(actionAttribute.CommandType))
{
throw new InvalidOperationException();
}
commandType = actionAttribute.CommandType;
}
// Synchronous handler
if ((member.Name == "Handle" || actionAttribute != null) &&
(member.ReturnType == typeof(void) || !typeof(Task).IsAssignableFrom(member.ReturnType)))
{
result = new CommandHandlerActionDescriptor(commandType, member);
return(true);
}
// Asynchronous handler
if ((member.Name == "HandleAsync" || actionAttribute != null) &&
(typeof(Task).IsAssignableFrom(member.ReturnType)))
{
result = new CommandHandlerActionDescriptor(commandType, member);
return(true);
}
result = default;
return(false);
}
