/// <summary>
/// Register methods marked with the [CommandHandler] attribute as command handlers.
/// <para>Supported signatures for methods marked with [CommandHandler] are: (Methods can be named differently)</para>
/// <para>void HandleCommand(TCommand command);</para>
/// <para>Task HandleCommandAsync(TCommand command);</para>
/// <para>Task HandleCommandAsync(TCommand command, CancellationToken cancellationToken);</para>
/// </summary>
/// <typeparam name="TAttributed">Type of the object which contains the methods marked with the [CommandHandler] attribute.</typeparam>
/// <param name="attributedHandlerFactory">Factory which will provide an instance of the specified <typeparamref name="TAttributed"/> type.</param>
public void Register <TAttributed>(Func <TAttributed> attributedHandlerFactory) where TAttributed : class
{
if (attributedHandlerFactory == null)
{
throw new ArgumentNullException(nameof(attributedHandlerFactory));
}
Type attributedObjectType = typeof(TAttributed);
// Get all public methods marked with CommandHandler attribute.
IEnumerable <CommandHandlerAttributeMethod> commandHandlerMethods = CommandHandlerAttributeMethod.FromType(attributedObjectType);
foreach (CommandHandlerAttributeMethod commandHandlerMethod in commandHandlerMethods)
{
MethodInfo registerCommandHandlerGenericMethodInfo = RegisterCommandHandlerOpenGenericMethodInfo.MakeGenericMethod(
attributedObjectType,
commandHandlerMethod.CommandType);
registerCommandHandlerGenericMethodInfo.Invoke(this, new object[]
{
attributedHandlerFactory, commandHandlerMethod
});
}
}
private void registerCommandHandlerMethod <TAttributed, TCommand>(Func <TAttributed> attributedObjectFactory, CommandHandlerAttributeMethod commandHandlerMethod)
where TAttributed : class
where TCommand : class, ICommand
{
Type commandType = typeof(TCommand);
CommandHandlerDelegate handleCommandDelegate;
if (_commandHandlerDelegatesByCommandType.TryGetValue(commandType, out handleCommandDelegate))
{
throw new InvalidOperationException($"Duplicate command handler registered for {commandType.Name}.");
}
CommandHandlerDelegate newHandleCommandDelegate = commandHandlerMethod.CreateDelegate <TAttributed, TCommand>(attributedObjectFactory);
_commandHandlerDelegatesByCommandType.Add(commandType, newHandleCommandDelegate);
}
