Cast object to generic - swift

Question

I am creating a function to be used in different occasions. But for this, I need to Cast the return of a function to the Object that I pass as generic in this main function.
func makeRequestToApi<T>(object: T, url: String) {
Alamofire.request(.GET, url).responseJSON { request in
if let json = request.result.value {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
let data = JSON(json)
let object: [T] = self.createProductObject(data) as Any as! [T]
dispatch_async(dispatch_get_main_queue()) {
self.delegate?.networkingDidUpdate(object)
}
}
}
}
}
I thought that I only need to call this way:
networkingController.makeRequestToApi(Product, url: Urls.menu)
This function will return an array of products self.createProductObject(data) -> [Product]
But Xcode make me add .self to the first parameter in makeRequestToApi
networkingController.makeRequestToApi(Product.self, url: Urls.menu)
This way, as I see, Swift will not convert the return of my class to Product as I need it.
Anyone knows what I need to do?
Thank you.

Answer 1

You probably want something like this:
func makeRequestToApi<T>(create: JSON -> [T], url: String) {
Alamofire.request(.GET, url).responseJSON { request in
if let json = request.result.value {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
let data = JSON(json)
let object = create(data)
dispatch_async(dispatch_get_main_queue()) {
self.delegate?.networkingDidUpdate(object)
}
}
}
}
}
makeRequestToApi(createProductObject, url: Urls.menu)
EDIT: This compiles for me (you probably have to adjust your delegate method):
import Foundation
struct Product {}
protocol Delegate : class {
func networkingDidUpdate<T>(obj: [T])
}
class Test {
weak var delegate : Delegate?
func makeRequestToApi<T>(create: JSON -> [T], url: String) {
Alamofire.request(.GET, url).responseJSON { request in
guard let json = request.result.value else { return }
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
let object = create(JSON(json))
dispatch_async(dispatch_get_main_queue()) {
self.delegate?.networkingDidUpdate(object)
}
}
}
}
func createProductObject(json: JSON) -> [Product] {
return [Product()]
}
}
let test = Test()
test.makeRequestToApi(test.createProductObject, url: "")