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DI Binding to a subclass

It is possible to archive this with scaldi, but the problem is with the way Environment is defined and used. I assume (at least error tells me this) that Environment is invariant on both of it's type arguments. This is the problem, because you want to treat Environment[User, Authenticator] as a superclass of Environment[User, SessionAuthenticator]. It is not the case if both type arguments are defined as invariant. To fix this issue you can just make the second type argument of Environment covariant with +:

trait Environment[A, +B]

Theoretically it should fix the compile error you shown.

Categories : Scala

Related to : DI Binding to a subclass
how to init a UIButton subclass?
Two things you need there -- (1) cvstPosition need an initial value, either in the declaration or in the init before you call super.init(). (2) That call to fatalError is put in so you don't forget to implement the initializer -- it's basically an on-purpose crash. Delete! Setting initial value in the declaration, no need for an init: class CVSTButton : UIButton { var cvstPosition: Double =

Categories : Swift
Use overridden method from subclass
You need to inject the Sub in the object to achieve that. If you let it to be in the class A constructor, it only has visibility to A.Sub. Then, make a constructor for A that accepts an A.Sub and subclasses: public A(Sub sub) { this.sub = sub; }

Categories : Java
Swift subclass UIView
I usually do something like this, its a bit verbose. class MyView: UIView { override init (frame : CGRect) { super.init(frame : frame) addBehavior() } convenience init () { self.init( } required init(coder aDecoder: NSCoder) { fatalError("This class does not support NSCoding") } func addBehavior (){ print("Ad

Categories : IOS
Why doesn't my subclass' variable exist?
You need to let the compiler know the class type. As you can see in the error message the compiler currently thinks the class is UILable so you need to update the class type (or cast the class type if you can't).

Categories : IOS
Find invocations of subclass method
Well, due to polymorphism, there's not a good way for the IDE to know that a given Foo isn't potentially a Bar -- so it will show you all calls to doStuff. I suppose it could do more analysis to determine that the concrete type of a Foo really is a Foo -- for example, in the case: final Foo foo = new Foo(); it is definitely not a Bar -- but that's a lot of work for little benefit. You will not

Categories : Java
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