Registration of IoC containers from several assemblies

Question

I try to understand what is best practice for registration of the objects into ioc container from different projects of one solution.

I have a solution with 4 projects and I saw a solution to create installers in each of the projects and then in one place call somtehing like this:

_container = new WindsorContainer();
            var assemblyNames = new[] {"Dal", "Utils" };
            _container.Install(assemblyNames.Select(
                    x => (IWindsorInstaller)new AssemblyInstaller(Assembly.Load(x),
                        new InstallerFactory())).ToArray());

But also I saw a solution that in each project, there is a creation of container, and inside there is a registration of the objects that are relevant to this specific project.

My question is: what is the best practice for this situation?

Answer 1

We have an example here : A web solution which consists of many projects : One Core project and many other which reference the core. All of them end up in different folders (or copied after build to the core/bin if you like). At start time we load them dynamically and then load the IWindsorInstallers from them. We load dlls like that :

public static void LoadMoules()
{            
    string basePath = AppDomain.CurrentDomain.BaseDirectory;
    string binPath = Path.Combine(basePath, "bin");
    DirectoryInfo binFolder = new DirectoryInfo(binPath);
    IEnumerable<FileInfo> binFiles = binFolder.EnumerateFiles("*.dll", SearchOption.AllDirectories);
    Assembly[] domainAssemblies = AppDomain.CurrentDomain.GetAssemblies();
    try
    {
        foreach (var binFile in binFiles)
        {
            AssemblyName assemblyName = AssemblyName.GetAssemblyName(binFile.FullName);
            if (domainAssemblies.All(x => x.FullName != assemblyName.FullName))
            {
                Assembly.Load(assemblyName.FullName);
                Debug.WriteLine($"Loading {assemblyName.FullName}");
            }
        }
    }
    catch (Exception exception)
    {
       DynamicModuleLoaderEventSource.Log.FailedToLoadAssembly(exception.Message + exception.StackTrace);

    }    }

Then we get the registrations :

    try
    {
        foreach(Assembly moduleAssembly in installationModules)
        {
            // satellite proejct assemblies 

            Debug.WriteLine(moduleAssembly.FullName);
            ContainerRegisterEventSource.Log.InstallAssembly(moduleAssembly.FullName);
            container.Install(FromAssembly.Instance(moduleAssembly));
        }

        container.Install(FromAssembly.This()); // the core assembly
    }
    catch(Exception exception)
    {
        ContainerRegisterEventSource.Log.Exception(exception.Message + exception.StackTrace);
        Trace.WriteLine("SetupContainerForMigrations error : " + exception.Message + Environment.NewLine + exception.StackTrace);
    }

Doing it this way you will end up with one container with all the dependencies.