Webservice returning nil - swift

Question

I am having trouble populating a UITextField with my returnHTML data that I get from my web-service.
If I have my web-service such that:
import Foundation;
class WebSessionCredentials {
static let requestURL = URL(string:"xxxx.on.ca/getData.aspx?requestType=Tech")!
var htmlbody: String?
var instancedTask: URLSessionDataTask?
static var sharedInstance = WebSessionCredentials()
init() {
self.instancedTask = URLSession.shared.dataTask(with: WebSessionCredentials.requestURL) { [weak self] (data,response,error) in
if let error = error {
// Error
print("Client Error: \(error.localizedDescription)")
return
}
guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
print("Server Error!")
return
}
guard let mime = response.mimeType, mime == "text/html" else {
print("Wrong mime type!");
return
}
if let htmlData = data, let htmlBodyString = String(data: htmlData, encoding: .utf8) {
self?.htmlbody = htmlBodyString;
};
};
};
};
Through this I should be able to access the returned HTML response through WebSessionCredentials.sharedInstance.htmlbody;
Verifying this in playground I seem to be getting the correct response within the class but when calling htmlbody from outside the class I get a nil response - I am out of ideas in terms of how to send that HTML string that I get from the class to outside the function. This question is built off another question I have posted a couple days earlier -> Delegating privately declared variables to a public scope
Thanks,

Answer 1

Rather than implementing the dataTask in the init method add a method run with completion handler
class WebSessionCredentials {
enum WebSessionError : Error {
case badResponse(String)
}
static let requestURL = URL(string:"xxxx.on.ca/getData.aspx?requestType=Tech")!
static var sharedInstance = WebSessionCredentials()
func run(completion : #escaping (Result<String,Error>) -> Void) {
let instancedTask = URLSession.shared.dataTask(with: WebSessionCredentials.requestURL) { (data,response,error) in
if let error = error {
// Error
print("Client Error: \(error.localizedDescription)")
completion(.failure(error))
return
}
guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
completion(.failure(WebSessionError.badResponse("Server Error!")))
return
}
guard let mime = response.mimeType, mime == "text/html" else {
completion(.failure(WebSessionError.badResponse("Wrong mime type!")))
return
}
completion(.success(String(data: data!, encoding: .utf8)!))
}
instancedTask.resume()
}
}
And use it
WebSessionCredentials.sharedInstance.run { result in
switch result {
case .success(let htmlBody): print(htmlBody)
case .failure(let error): print(error)
}
}