Implementing Receipt Validation in Swift 3

Question

I am developing an iOS app in Swift 3 and trying to implement receipt validation following this tutorial: http://savvyapps.com/blog/how-setup-test-auto-renewable-subscriptio

Answer 1

//too low rep to comment

Yasin Aktimur, thanks for your answer, it's awesome. However, looking at Apple documentation on this, they say to connect to iTunes on a separate Queue. So it should look like this:

func receiptValidation() {

    let SUBSCRIPTION_SECRET = "secret"
    let receiptPath = Bundle.main.appStoreReceiptURL?.path
    if FileManager.default.fileExists(atPath: receiptPath!){
        var receiptData:NSData?
        do{
            receiptData = try NSData(contentsOf: Bundle.main.appStoreReceiptURL!, options: NSData.ReadingOptions.alwaysMapped)
        }
        catch{
            print("ERROR: " + error.localizedDescription)
        }
        let base64encodedReceipt = receiptData?.base64EncodedString(options: NSData.Base64EncodingOptions.endLineWithCarriageReturn)
        let requestDictionary = ["receipt-data":base64encodedReceipt!,"password":SUBSCRIPTION_SECRET]
        guard JSONSerialization.isValidJSONObject(requestDictionary) else {  print("requestDictionary is not valid JSON");  return }
        do {
            let requestData = try JSONSerialization.data(withJSONObject: requestDictionary)
            let validationURLString = "https://sandbox.itunes.apple.com/verifyReceipt"  // this works but as noted above it's best to use your own trusted server
            guard let validationURL = URL(string: validationURLString) else { print("the validation url could not be created, unlikely error"); return }

            let session = URLSession(configuration: URLSessionConfiguration.default)
            var request = URLRequest(url: validationURL)
            request.httpMethod = "POST"
            request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringCacheData
            let queue = DispatchQueue(label: "itunesConnect")
            queue.async {
                let task = session.uploadTask(with: request, from: requestData) { (data, response, error) in
                    if let data = data , error == nil {
                        do {
                            let appReceiptJSON = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? NSDictionary
                            print("success. here is the json representation of the app receipt: \(appReceiptJSON)")    
                        } catch let error as NSError {
                            print("json serialization failed with error: \(error)")
                        }
                    } else {
                        print("the upload task returned an error: \(error ?? "couldn't upload" as! Error)")
                    }
                }
                task.resume()
            }

        } catch let error as NSError {
            print("json serialization failed with error: \(error)")
        }
    }
}