NSURLSession GET Request - Swift 4.2

ImageResponse.swift

struct ImageResponse: Codable {
    var message:String
    var totalRecord:Int
    var totalPage:Int
    var nextPage:String
    var images:[Image]
    
    enum CodingKeys: String, CodingKey {
        case message
        case totalRecord
        case totalPage
        case nextPage
        case images = "data"
    }

}

struct Image: Codable {
    var imageId: Int
    var title:String
    var imageUrl: String
    
    enum CodingKeys: String, CodingKey {
        case imageId = "iImageId"
        case title = "vTitle"
        case imageUrl = "txImageUrl"
    }
}

NSURLSession GET Request

        guard let urlEncodedString = (AppConstants.URL.imageDownload + "?image_id=\(imageIdCalculated)").addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) else {
            return
        }
        let url = URL(string: urlEncodedString)!
        let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
            if let er = error {
                print(er)
                Utils.showAlertController(with: er.localizedDescription, viewController: self)
                return
            }
            guard let unwrappedData = data else { return }
            do {
                let imageResponse = try JSONDecoder().decode(ImageResponse.self, from: unwrappedData)
                if imageResponse.images.count == 0 {
                    Utils.showAlertController(with: imageResponse.message, viewController: self)
                    return
                }
                DispatchQueue.main.async {
                    // Call UI update in main thread
                }
            } catch {
                print("json error: \(error)")
            }
        }
        task.resume()