what am I doing wrong Swift 3 http request and response - ios

Question

I'm having big problems in a project I'm currently working with.
I've been reading about URLSession various places but all of them seem to be outdated and refers to NSURLSession I thought that they would be fairly similar and they probably are but for a newbie like me I'm lost. what I do is not working and I do not like solutions I find because they all do their work in a controller..
http://swiftdeveloperblog.com/image-upload-with-progress-bar-example-in-swift/
this one for instance. I'm using the PHP script but wanted to make a networking layer I could invoke and use at will. but I'm lacking a good resource from where I could learn about how to use this api.
every place I find is similar to the link above or older. the few newer seem to also follow the pattern without really explaining how to use this api.
at the same time I'm new to the delegate pattern in fact I only know that it is something that is heavily used in this Api but I have no IDEA how or why.
Basically I need help finding my way to solve this problem here:
I've tried to do something like this:
public class NetworkPostRequestor:NSObject,NetworkPostRequestingProtocol,URLSessionTaskDelegate,URLSessionDataDelegate
{
public var _response:HTTPURLResponse
public override init()
{
_response = HTTPURLResponse()
}
public func post(data: Data, url: URL)
{
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.setValue("Keep-Alive", forHTTPHeaderField: "Connection")
let configuration = URLSessionConfiguration.default
let session = URLSession(configuration: configuration,delegate: self, delegateQueue: OperationQueue.main)
let task = session.uploadTask(with: request, from: data)
task.resume()
}
public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: #escaping (URLSession.ResponseDisposition) -> Void)
{
_response = response as! HTTPURLResponse
}
}
however I never even hit the PHPserver. the server when hit will say something like this in the terminal:
[Tue Mar 7 11:43:20 2017] 192.168.250.100:64265 [200]: /
[Tue Mar 7 11:43:20 2017] 192.168.250.100:64266 [404]: /favicon.ico - No such file or directory
Well that is when I hit it with my browser and there is no image with it. but alt least I know that it will write something with the terminal if it hits it. Nothing happens And without a resource to teach me this api I'm afraid I will never learn how to fix this or even if I'm doing something completely wrong.
I'm using Swift 3 and Xcode 8.2.1
Edit:
I've added this method to the class and found that I hit it every single time.
public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?)
{
_error = error.debugDescription
}
the debug description have this string "some"

Answer 1

I never used this exact procedure with tasks but rather use the methods with callback. I am not sure if in the background there should be much of a difference though.
So to generate the session (seems pretty close to your):
let configuration = URLSessionConfiguration.default
let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: OperationQueue.main)
Then I generate the request which stupidly enough needs an URL in the constructor:
var request = URLRequest(url: URL(string: "www.nil.com")!) // can't initialize without url
request.url = nil
Adding url with query parameters (you can just set the URL in your case, I have a tool to handle a few cases):
fileprivate func injectQueryParameters(request: inout URLRequest) {
if let query = queryParameters.urlEncodedString {
let toReturn = endpoint.url + "?" + query
if let url = URL(string: toReturn) {
request.url = url
} else {
print("Cannot prepare url: \(toReturn)")
}
} else {
let toReturn = endpoint.url
if let url = URL(string: toReturn) {
request.url = url
} else {
print("Cannot prepare url: \(toReturn)")
}
}
}
Then the form parameters. We mostly use JSON but anything goes here:
fileprivate func injectFormParameters( request: inout URLRequest) {
if let data = rawFormData {
request.httpBody = data
} else if let data = formParameters.urlEncodedString?.data(using: .utf8) {
request.httpBody = data
}
}
And the headers:
fileprivate func injectHeaders(request: inout URLRequest) {
headers._parameters.forEach { (key, value) in
if let stringValue = value as? String {
request.setValue(stringValue, forHTTPHeaderField: key)
}
}
}
So in the end the whole call looks something like:
class func performRequest(request: URLRequest, callback: (([String: Any]?, NSError?) -> Void)?) {
let configuration = URLSessionConfiguration.default
let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: OperationQueue.main)
let task = session.dataTask(with: request) { data, response, error in
// Response is sent here
if let data = data {
callback?((try? JSONSerialization.jsonObject(with: data, options: .allowFragments)) as [String: Any]?, error)
} else {
callback?(nil, error)
}
}
task.resume()
}
I hope this puts you on the right track. In general you do have a few open source libraries you might be interested in. Alamofire is probably still used in most cases.