Swift Generic Class implementing an Objective-C Protocol - objective-c

Question

My intention is to create a generic class in Swift which conforms to an Objective-C protocol:
The class is:
class BaseViewFactoryImpl<T> : NSObject, BaseView {
func getNativeInstance() -> AnyObject {
return String("fsd")
}
}
The protocol BaseView is:
#protocol BaseView < NSObject >
- (id)getNativeInstance;
#end
The compiler tells me:
Type 'BaseViewFactoryImpl<T>' does not conform to protocol 'BaseView'
If I delete <T> then there is no error.
What is wrong here? How can I get the correct generic class implementation?

Answer 1

//BaseViewFactory.swift
class BaseViewFactoryImpl<T> : NSObject, BaseView {
func getNativeInstance() -> AnyObject {
return String("fsd")
}
//BaseViewProtocol.h
#protocol BaseView <NSObject>
- (id)getNativeInstance;
#end
//BridgingHeader.h
#import "BaseClassProtocol.h"
Your code should work. Have you created the bridging header to import the obj-C protocol file?

Answer 2

Starting with Swift 3, you need to use Any, not AnyObject, to represent generic id values coming from Objective-C.
This builds with no errors:
class BaseViewFactoryImpl<T> : NSObject, BaseView {
func getNativeInstance() -> Any {
return "fsd"
}
}

Answer 3

If you create a new generic view model, when you try to create any subclass of the generic view model, you need to declare the subclass as a generic class as well. It's kind of annoy.
For a better way, you can use typealias to declare the instance's type instead of using generic:
protocol BaseView {
typealias T
func getNativeInstance() -> T!
}
class StringViewModel : BaseView {
typealias T = String
func getNativeInstance() -> String! {
return T()
}
}