Why isn't my Weather Underground data not printing in Swift 3? - swift

Question

I'm having an issue printing data from Weather Underground. My code works with other data sources, just not Weather Underground. I have even tried replacing the URL with actual data (i.e. https://api.wunderground.com/api/APIKEY/forecast/geolookup/forecast/q/94129.json"), but it doesn't print.
Any suggestions on what it could be?
import Foundation
import UIKit
class APIManager {
func weatherJSON(zip: String, completion: #escaping ([Weather]) -> Void) {
let baseUrlString = "https://api.wunderground.com/api/APIKEY/forecast/geolookup/forecast/q/\(zip).json"
guard let url = URL(string: baseUrlString) else { return }
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard error == nil, let data = data else { return }
do {
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [[String: Any]] else { return }
// MARK: Print JSON
print(json)
var weatherList = [Weather]()
for item in json {
if let weather = Weather.create(from: item) {
weatherList.append(weather)
}
}
completion(weatherList)
} catch {
print("Uh oh. You have an error with \(zip)!")
}
}
task.resume()
}
}
EDIT: SOLVED
I have used the code posted below and am now seeing errors.

Answer 1

I'd suggest changing this to report errors:
enum WeatherError Error {
case badURL
case invalidJSON
}
func weatherJSON(zip: String, completion: #escaping ([Weather]?, Error?) -> Void) {
let baseUrlString = "https://api.wunderground.com/api/APIKEY/forecast/geolookup/forecast/q/\(zip).json"
guard let url = URL(string: baseUrlString) else {
completion(nil, WeatherError.badURL)
return
}
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard error == nil, let data = data else {
completion(nil, error)
return
}
do {
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [[String: Any]] else {
completion(nil, WeatherError.invalidJSON)
return
}
// MARK: Print JSON
print(json)
var weatherList = [Weather]()
for item in json {
if let weather = Weather.create(from: item) {
weatherList.append(weather)
}
}
completion(weatherList, nil)
} catch let parseError {
print("Uh oh. You have an error with \(zip)!")
if let responseString = String(data: data, encoding: .utf8) {
print("responseString = \(responseString)")
}
completion(nil, parseError)
}
}
task.resume()
}
Then, when you call it, you can see what the error was
weatherJSON(zip: something) { weatherReports, error in
guard let weatherReports = weatherReports, error == nil else {
print(error)
return
}
// use weatherReports here
}
This won't solve your problem, but it will help you diagnose what the issue is.