Object initialization with protocol and class name in swift

Question

In Ojective-C I wrote:

id <MyProtocol> object = [[NSClassFromString(@"aClassName") alloc] initWithObject:obj];

I would like to write this in Swift.

Is there to do the same or am I out of the language paradigm ?

edit :

Here's my context. Somewhere I have :

- (instancetype)initWithObject:(NSArray *)array andClassName:(NSString *)className {
    self = [self initWithClassName:className];
    if(self) {
        _members    = [[NSMutableArray alloc] init];
        for(id obj in array) {
            id <MyProtocol> object = [[NSClassFromString(className) alloc] initWithObject:obj];
            [_members addObject:object];
        };
    }
    return self;
}

Answer 1

In Swift, you will need a generic class.

You class will have a generic type <T : MyProtocol>, members will be of type [T] and you can use T to create new instance.

You won't need to pass the className as a parameter.

Answer 2

In order for you to call that initializer on the class, you need to know that the class supports that initializer. So let's make the initializer required by the MyProtocol protocol:

protocol MyProtocol {
  init(object: AnyObject)
}

And then you can just do NSClassFromString, then cast the result to MyProtocol.Type (to assert that the class is a subtype of MyProtocol), which allows you to use the initializer you want:

let object = (NSClassFromString(className) as! MyProtocol.Type)(object: obj)