Question

I am trying to register a different instance of my database depending upon the constructor name. I am familiar with the “first wins” concept in Castle Windsor, but apparently I don’t fully understand it.

I would like uaxDB parameter name below to signal ControllerInstaller to give me the instance with UAXmongoURL, UAXmongoConnection parameters. Instead I am getting the first instance, with USERmongoURL and USERmongoconnection parameters. So…first wins, but even when I used named instances? How can I fix so that the named instance trumps any default ordering?

Note I don’t just want to swap the order of the two components, because I’m about to have yet more instances so I need to scale beyond 2….said another way, I really need to understand what I’m doing wrong.

// Trying to avoid this constructor declaration in favor of the uncommented constructor
// public DBViewerModel(IMongoConnection devDB, IMongoConnection uaxDB, IMongoConnection prodDB)
public DBViewerModel(IMongoConnection mongoConnection)
{
    //this.devMongoConnection = devDB;
    //this.uaxMongoConnection = uaxDB;
    //this.prodMongoConnection = prodDB;
    this.mongoConnection = mongoConnection;
}

With registration…

container.Register(
    Component
        .For<IMongoConnection>()
        .Named("dataDB")
        .ImplementedBy<MongoConnection>()
        .DependsOn(Property.ForKey("DBlocation").Eq(USERmongoURL),
                   Property.ForKey("DB").Eq(USERmongoCollection))
        .LifeStyle.PerWebRequest,

    Component
        .For<IMongoConnection>()
        .Named("uaxDB")
        .ImplementedBy<MongoConnection>()
        .DependsOn(Property.ForKey("DBlocation").Eq(UAXmongoURL),
                   Property.ForKey("DB").Eq(UAXmongoCollection))
        .LifeStyle.PerWebRequest);

Answer 1

You can specify explicitly what component should be injected by service overrides:

https://github.com/castleproject/Windsor/blob/master/docs/registering-components-one-by-one.md#supplying-the-component-for-a-dependency-to-use-service-override

This is the older way how to do it. If you are using latest version of Windsor, it is prefferable to use DependsOn(Dependency.OnComponent("uaxDB", "uaxDB")) API instead.