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TheBigoso /\
3,217 PointsNetworkOperation.swift > "Extra Argument 'error' in call" with NSJSONSerialization
I'm getting the error message "Extra argument 'error' in call" with the line.... "let jsonDictionary = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: nil) as? [String: AnyObject]"
After looking around I found the answer....thus, change the code to look like this as shown below... " let jsonDictionary = try!NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String: AnyObject] completion(jsonDictionary)"
Hope this helps!
import Foundation
class NetworkOperation {
lazy var config: NSURLSessionConfiguration = NSURLSessionConfiguration.defaultSessionConfiguration()
lazy var session: NSURLSession = NSURLSession(configuration: self.config)
let queryURL: NSURL
typealias JSONDictionaryCompletion = ([String: AnyObject]? -> Void)
init(url: NSURL) {
self.queryURL = url
}
func downloadJSONFromURL(completion: JSONDictionaryCompletion) {
let request = NSURLRequest(URL: queryURL)
let dataTask = session.dataTaskWithRequest(request) {
(let data, let response, let error) in
// 1. Check HTTP response for successful GET request
if let httpResponse = response as? NSHTTPURLResponse {
switch httpResponse.statusCode {
case 200:
// 2. Create JSON object with data
let jsonDictionary = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: nil) as? [String: AnyObject]
completion(jsonDictionary)
default:
print("GET request not successful. HTTP status code: \(httpResponse.statusCode)")
}
} else {
print("Error: Not a valid HTTP response")
}
}
dataTask.resume()
}
}
1 Answer
Dennis Parussini
Treehouse Project ReviewerYour code looks good so far, just one thing you have to change:
let jsonDictionary = try! NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String: AnyObject]
Of course you should rather do:
do {
let jsonDictionary = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String: AnyObject]
} catch {
//Handle the error
}