genericsSwift.swift

func genericFetch<T: Decodable>(urlString: String, completion: @escaping (T) -> ()) {

  Alamofire.request(urlString, method: .get).validate(statusCode: 200..<300).response { response in

    guard response.error == nil else {
        print("error calliing on \(urlString)")
        return
    }

    guard let data = response.data else {
        print("there was an error with the data")
        return
    }

    do {
        let model = try JSONDecoder().decode(T.self, from: data)
        completion(model)
    } catch let jsonErr {
        print("failed to decode, \(jsonErr)")
    }

  }
}