How can I parse JSON from a rest API in swift - swift

Question

I'm modifying code from 'Hacking with swift' Project 7 to take a JSON file using an API and placing it in a table view
I'm at a bit of loss of what to do next, tried moving around the call to the parse function and using the commented out code
override func viewDidLoad() {
super.viewDidLoad()
let username = "UserName"
let password = "Password"
let loginData = String(format: "%#:%#", username,
password).data(using: String.Encoding.utf8)!
let base64LoginData = loginData.base64EncodedString()
let url = URL(string: "......")!
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("Basic \(base64LoginData)", forHTTPHeaderField:
"Authorization")
let task = URLSession.shared.dataTask(with: request) { data,
response,
error in
guard let data = data, error == nil else {
print("error")
return
}
if let httpStatus = response as? HTTPURLResponse {
parse(json: data)
print("status code = \(httpStatus.statusCode)")
}
}
task.resume()
}
// if let url = URL(string: urlstring){
// if let data = try? Data(contentsOf: url){
// parse(json: data)
// return
// }
// }
// showError()
//}
func parse(json: Data) {
let decoder = JSONDecoder()
if let jsonPetitions = try? decoder.decode(Petitions.self, from:
json) {
petitions = jsonPetitions.results
tableView.reloadData()
}
}
I receive a status code of '200' so I know the API call works fine.
The issue seems to be with calling the parse function I get the
following error "Call to method 'parse' in closure requires explicit
'self.' to make capture semantics explicit"

Answer 1

1- The error means to add self here
self.parse(json: data)
2- You should reload the table in main thread as callback of URLSession.shared.dataTask runs in a background thread to avoid un-expected results/crashes
DispatchQueue.main.async {
self.tableView.reloadData()
}