Autofac LifetimeScope with BeginLifetimeScope not working - autofac

I am trying to evaluate the scoping of Autofac and as I understand it, when an instance has been declared as InstancePerLifetimeScope, then within the using(container.BeginLifetimeScope()) block, we should get the same instance. But in another such block, we should get a different instance. But my code (in linqpad) gives me the same instance. Windsor's lifestylescope however works as I think it should.
Code:
static IContainer glkernel;
void Main()
{
var builder = new ContainerBuilder();
builder.RegisterType<Controller>();
builder.RegisterType<A>().As<IInterface>().InstancePerLifetimeScope();
glkernel = builder.Build();
using (glkernel.BeginLifetimeScope()){
Controller c1 = glkernel.Resolve<Controller>();
c1.GetA();//should get instance 1
c1.GetA();//should get instance 1
}
using (glkernel.BeginLifetimeScope()){
Controller d = glkernel.Resolve<Controller>();
d.GetA();//should get instance 2
d.GetA();//should get instance 2
}
}
public interface IInterface
{
void DoWork(string s);
}
public class A : IInterface
{
public A()
{
ID = "AAA-"+Guid.NewGuid().ToString().Substring(1,4);
}
public string ID { get; set; }
public string Name { get; set; }
public void DoWork(string s)
{
Display(ID,"working...."+s);
}
}
public static void Display(string id, string mesg)
{
mesg.Dump(id);
}
public class Controller
{
public Controller()
{
("controller ins").Dump();
}
public void GetA()
{
//IInterface a = _kernel.Resolve<IInterface>();
foreach(IInterface a in glkernel.Resolve<IEnumerable<IInterface>>())
{
a.DoWork("from A");
}
}
}
The output is:
controller ins
AAA-04a0
working....from A
AAA-04a0
working....from A
controller ins
AAA-04a0
working....from A
AAA-04a0
working....from A
Perhaps my understanding of scoping is wrong. If so, can you please explain.
What do I have to do to get a different instance in the second block?

The problem is you're resolving things out of the container - the glkernel instead of out of the lifetime scope. A container is a lifetime scope - the root lifetime scope.
Resolve out of the lifetime scope instead. That may mean you need to change up your controller to pass in the list of components rather than using service location.
public class Controller
{
private IEnumerable<IInterface> _interfaces;
public Controller(IEnumerable<IInterface> interfaces)
{
this._interfaces = interfaces;
("controller ins").Dump();
}
public void GetA()
{
foreach(IInterface a in this._interfaces)
{
a.DoWork("from A");
}
}
}
Then it's easy enough to switch your resolution code.
using (var scope1 = glkernel.BeginLifetimeScope()){
Controller c1 = scope1.Resolve<Controller>();
c1.GetA();
c1.GetA();
}
using (var scope2 = glkernel.BeginLifetimeScope()){
Controller c2 = scope2.Resolve<Controller>();
c2.GetA();
c2.GetA();
}
The Autofac wiki has some good information on lifetime scopes you might want to check out.

Related

How do I combine a Controlled Lifetime relationship type (i.e. Owned<T>) with a delegate factory?

In my application, I have a service that requires a constructor parameter not resolved by Autofac, that I instantiate using a delegate factory:
public class Service
{
public Service(string parameter /*, ... other dependencies */)
{
}
public delegate Service Factory(string parameter);
}
This works great! I really love this feature.
I also like the Controlled Lifetime relationship, so I can let my component depend on a Func<Owned<ISomething>> like this:
public class Component
{
private Func<Owned<ISomething>> _somethingFactory;
/* constructor omitted for brevity */
public void DoSomethingUseful()
{
using (var ownedSomething = _somethingFactory())
{
/* Lots of useful code here */
}
}
}
My problem is that now I want to combine the two. I can't have an instance of Func<Owned<Service>> injected, because it needs that parameter, so my current solution is to abstract the factory away into another service, say IServiceFactory:
public interface IServiceFactory
{
Service Create(string parameter);
}
...implemented as such:
public class ServiceFactory : IServiceFactory
{
private Service.Factory _internalFactory;
public ServiceFactory(Service.Factory internalFactory)
{
_internalFactory = internalFactory;
}
public Service Create(string parameter)
{
return _internalFactory(parameter);
}
}
My component then becomes this:
public class Component
{
Func<Owned<IServiceFactory>> _serviceFactoryFactory;
/* ... */
}
The need for such a field name leaves a bad taste in my mouth to the point that I suspect there must be a cleaner way to handle this case.
Is there another way?
You could change your injected factory to include the string parameter:
private Func<string, Owned<ISomething>> _somethingFactory;
Then you can pass the string to the factory when you want to create a new instance:
public void DoSomethingUseful()
{
using (var ownedSomething = _somethingFactory("my parameter"))
{
/* Lots of useful code here */
}
}
I've created a .NET Fiddle with a small working sample.

Autofac: cannot resolve dependency using factory after ContainerBuilder.Update()

My problem is that I want to use Func<> factory to resolve dependency. And in if I use ContainerBuilder Update() (I need it for mocking some services in integration tests), this factories still resolve outdated instances.
I created simple scenario to reproduce the problem:
class Program
{
static void Main(string[] args)
{
var containerBuilder = new ContainerBuilder();
containerBuilder.RegisterType<Test>().As<ITest>();
containerBuilder.RegisterType<Test1Factory>().As<ITestFactory>();
containerBuilder.RegisterType<TestConsumer>().AsSelf();
var container = containerBuilder.Build();
var tc1 = container.Resolve<TestConsumer>();
var cbupdater = new ContainerBuilder();
cbupdater.RegisterType<Test2>().As<ITest>();
cbupdater.RegisterType<Test2Factory>().As<ITestFactory>();
cbupdater.Update(container);
var tc2 = container.Resolve<TestConsumer>();
Console.ReadLine();
}
}
public interface ITest
{
int Id { get; set; }
}
public class Test : ITest
{
public Test()
{
Id = 1;
}
public int Id { get; set; }
}
public class Test2 : ITest
{
public Test2()
{
Id = 2;
}
public int Id { get; set; }
}
public interface ITestFactory
{
ITest Create();
}
public class Test1Factory : ITestFactory
{
public ITest Create()
{
return new Test();
}
}
public class Test2Factory : ITestFactory
{
public ITest Create()
{
return new Test2();
}
}
public class TestConsumer
{
public TestConsumer(Func<ITest> testFactory, ITest test, ITestFactory customFactory)
{
Console.WriteLine("factory: " + testFactory().Id);
Console.WriteLine("direct: " + test.Id);
Console.WriteLine("MyCustomFactory: " + customFactory.Create().Id);
Console.WriteLine("*************");
Console.WriteLine();
}
}
The output is:
factory: 1 direct: 1 MyCustomFactory: 1
factory: 1 direct: 2 MyCustomFactory: 2
Notice "factory: 1" in both cases.
Am I missing something or I have to create my cusom factory in this scenario?
P.S.
Autofac 3.5.2 or 4.0 beta 8-157
.net 4.5.1
That's by design unfortunately, the reasons, I don't know. Looking at the Autofac code gives you a better insight on how they register items with the same interface definition, in short, all registrations are maintained but the last registration wins (ref). Wait...that's not all, weirdly, for Fun<...>, you actually get them in order. You can easily test by changing the constructor of the TestConsumer class to:
public TestConsumer(Func<ITest> testFactory, IEnumerable<Func<ITest>> testFactories, IEnumerable<ITest> tests, ITest test, ITestFactory customFactory)
{
// ...
}
Note that you get all the Funcs and the ITest registration. You are simply lucky that resolving ITest directly resolves to Test2.
Now, having said all of the above, there is a way described here. You have to create a container without the registration you want to override, therefore:
/// <summary>
/// This has not been tested with all your requirements
/// </summary>
private static IContainer RemoveOldComponents(IContainer container)
{
var builder = new ContainerBuilder();
var components = container.ComponentRegistry.Registrations
.Where(cr => cr.Activator.LimitType != typeof(LifetimeScope))
.Where(cr => cr.Activator.LimitType != typeof(Func<ITest>));
foreach (var c in components)
{
builder.RegisterComponent(c);
}
foreach (var source in container.ComponentRegistry.Sources)
{
builder.RegisterSource(source);
}
return builder.Build();
}
And you can simply change your main method to the following:
static void Main(string[] args)
{
var containerBuilder = new ContainerBuilder();
containerBuilder.RegisterType<Test>().As<ITest>();
containerBuilder.RegisterType<Test1Factory>().As<ITestFactory>();
containerBuilder.RegisterType<TestConsumer>().AsSelf();
var container = containerBuilder.Build();
var tc1 = container.Resolve<TestConsumer>();
container = RemoveOldComponents(container);
var cbupdater = new ContainerBuilder();
cbupdater.RegisterType<Test2>().As<ITest>();
cbupdater.RegisterType<Test2Factory>().As<ITestFactory>();
cbupdater.Update(container);
var tc2 = container.Resolve<TestConsumer>();
Console.ReadLine();
}
PS: Wouldn't it be great to have a method which does the exact opposite of PreserveExistingDefaults()

How can I achieve the following using IOC?

I want to use IOC with my service and I want to instead inject a class not an interface in the constructor as below in the services layer but I do not want to create a new object from the calling layer like var service = new InvoiceService(new ChangeInvoiceDueDateCommand()) instead I want to create something like this from my controller in MVC where the IInvoiceService is injected into the controller constructor but the problem I see is that
public InvoiceController(IInvoiceService invoiceService, IMapper mapper)
{
_invoiceService = invoiceService;
_mapper = mapper;
}
and then called like this
public ActionResult ChangeInvoiceDueDate(InvoiceChangeDueDateViewModel invoiceChangeDueDateViewModel )
{
var request = _mapper.Map<InvoiceChangeDueDateViewModel, ChangeInvoiceDuedateRequest>(invoiceChangeDueDateViewModel);
InvoiceChangeDueDateResponse response = _invoiceService.ChangeDueDate(request);
return View();
}
Service Layer
public class InvoiceService : IInvoiceService
{
private readonly ChangeInvoiceDueDateCommand _changeInvoiceDueDateCommand;
public InvoiceService(ChangeInvoiceDueDateCommand changeInvoiceDueDateCommand)
{
_changeInvoiceDueDateCommand = changeInvoiceDueDateCommand;
}
public InvoiceChangeDueDateResponse ChangeDueDate(ChangeInvoiceDuedateRequest invoiceChangeDueDateRequest)
{
_changeInvoiceDueDateCommand.Execute(invoiceChangeDueDateRequest);
return new InvoiceChangeDueDateResponse {Status = new Status()};
}
}
Command
public class ChangeInvoiceDueDateCommand : ICommand<ChangeInvoiceDuedateRequest>
{
private readonly IRepository<Invoice> _invoiceRepository;
readonly InvoiceDueDateChangeValidator _validator;
public ChangeInvoiceDueDateCommand(IRepository<Invoice> invoiceRepository)
{
_invoiceRepository = invoiceRepository;
_validator = new InvoiceDueDateChangeValidator();
}
public void Execute(ChangeInvoiceDuedateRequest request)
{
if (_validator.IsDuedateValid(request.NewDuedate))
{
Invoice invoice = _invoiceRepository.GetById(request.Id);
invoice.ChangedDueDate(request.NewDuedate);
_invoiceRepository.SaveOrUpdate(invoice);
}
else
{
throw new InvalidDueDateException();
}
}
}
ICommand
public interface ICommand<T> where T : IRequest
{
void Execute(T request);
}
IRequest
public interface IRequest
{
int Id { get; set; }
}
I worked it out. It was just a Windsor syntax issue. It ended up being as simple as registering the Command using the container.Register(Component.For<ChangeInvoiceDueDateCommand>());

How can I make Cirqus stop automatically creating new instances?

I have an aggregate root with a few events and commands. One of those commands is a CreateCommand. That command should create a new aggregate root with a given ID. Every other event/command should just update an existing aggregate root and fail if the aggregate root with the given ID doesn't exist.
How can I make Cirqus work this way?
This is how I configure my CommandProcessor:
var commandProcessor = CommandProcessor
.With()
#if DEBUG
.Logging(l =>
{
if (_useConsoleForLogging)
{
l.UseConsole(Logger.Level.Debug);
}
else
{
l.UseDebug(Logger.Level.Debug);
}
})
#endif
.EventStore(e => e.UseSqlServer(_connectionString, _eventsTableName))
.EventDispatcher(e => e.UseViewManagerEventDispatcher(viewManagers))
.Create();
This is the CreateCommand:
public class CreateCommand : ExecutableCommand
{
public CreateCommand()
{
CreatedGuid = Guid.NewGuid();
}
public Guid CreatedGuid { get; }
public override void Execute(ICommandContext context)
{
var root = context.Create<MyAggregateRoot>(CreatedGuid.ToString());
}
}
Of course this CreateCommand contains more code that emits a few events to immediately update some properties of the created instance, but I've removed them as they're not vital to this question.
You can do that by using ExecutableCommand to implement your own update command - you could call it UpdateCommand.
It could look something like this:
public abstract class UpdateCommand<TAggregateRoot>
{
readonly string _aggregateRootId;
protected UpdateCommand(string aggregateRootId)
{
_aggregateRootId = aggregateRootId;
}
public override void Execute(ICommandContext context)
{
var instance = context.Load<TAggregateRoot>(_aggregateRootId);
Update(instance);
}
public abstract void Update(TAggregateRoot instance);
}
and then all commands derived off of UpdateCommand would experience exceptions if they tried to address non-existing instances.
Similarly, you could ensure creation with a CreateCommand base class that would use ICommandContext's Create<TAggregateRoot> method to ensure that an existing instance was not accidentally being addressed.

testing controller using MOQ calling repository

I'm very new to Mocking. In the below example i'm using Moq and trying to create a _companyRepository. However the second test has a null ref. ie Company is not instantiated.
Assert.AreEqual(viewModel.Company.Name, "MyCompany");
Think i'm missing something silly here.
[TestClass]
public class ErrorControllerTest
{
private Mock<ICompanyRepository> _companyRepository;
public ErrorController CreateErrorController()
{
_companyRepository = new Mock<ICompanyRepository>();
_companyRepository.Setup(c => c.Get(2)).Returns(new Company {Name = "MyCompany"});
return new ErrorController(_companyRepository.Object);
}
[TestMethod]
public void Test()
{
var controller = CreateErrorController();
controller.Test(""); // action is called
var viewModel = (ErrorViewModel)controller.ViewData.Model;
Assert.IsInstanceOfType(controller.ViewData.Model, typeof(ErrorViewModel));
Assert.AreEqual(viewModel.Company.Name, "MyCompany");
}
}
controller
public class ErrorController : Controller
{
private readonly ICompanyRepository _companyRepository;
public ErrorController(ICompanyRepository companyRepository)
{
_companyRepository = companyRepository;
}
public ActionResult Test()
{
var company = _companyRepository.Get(2);
var viewModel = new ErrorViewModel
{
Company = company
};
return View(viewModel);
}
}
this works.... Guess i didn't compile everything. Very dumb.
Tho am i doing this the right way. Appreciate any comments.