Swift 3 URLSession.shared() Ambiguous reference to member 'dataTask(with:completionHandler:) error (bug)
IosJsonSwift3Ios Problem Overview
Hello I have working json parsing code for swift2.2 but when i use it for Swift 3.0 gives me that error
>ViewController.swift:132:31: Ambiguous reference to member 'dataTask(with:completionHandler:)'
My codes here
let listUrlString = "http://bla.com?batchSize=" + String(batchSize) + "&fromIndex=" + String(fromIndex)
let myUrl = URL(string: listUrlString);
let request = NSMutableURLRequest(url:myUrl!);
request.httpMethod = "GET";
let task = URLSession.shared().dataTask(with: request) {
data, response, error in
if error != nil {
print(error!.localizedDescription)
DispatchQueue.main.sync(execute: {
AWLoader.hide()
})
return
}
do {
let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSArray
if let parseJSON = json {
var items = self.categoryList
items.append(contentsOf: parseJSON as! [String])
if self.fromIndex < items.count {
self.categoryList = items
self.fromIndex = items.count
DispatchQueue.main.async(execute: {
self.categoriesTableView.reloadData()
AWLoader.hide()
})
}else if( self.fromIndex == items.count){
DispatchQueue.main.async(execute: {
AWLoader.hide()
})
}
}
} catch {
AWLoader.hide()
print(error)
}
}
task.resume()
Thanks for ideas.
Ios Solutions
Solution 1 - Ios
The compiler is confused by the function signature. You can fix it like this:
let task = URLSession.shared.dataTask(with: request as URLRequest) {
But, note that we don't have to cast "request" as URLRequest in this signature if it was declared earlier as URLRequest instead of NSMutableURLRequest:
var request = URLRequest(url:myUrl!)
This is the automatic casting between NSMutableURLRequest and the new URLRequest that is failing and which forced us to do this casting here.
Solution 2 - Ios
You have init'd myRequest as NSMutableURLRequest, you need this:
var URLRequest
Swift is ditching both the NSMutable... thing. Just use var for the new classes.
Solution 3 - Ios
Xcode 8 and Swift 3.0
Using URLSession:
let url = URL(string:"Download URL")!
let req = NSMutableURLRequest(url:url)
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config, delegate: self, delegateQueue: OperationQueue.main)
let task : URLSessionDownloadTask = session.downloadTask(with: req as URLRequest)
task.resume()
URLSession Delegate call:
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask,
didWriteData bytesWritten: Int64, totalBytesWritten writ: Int64, totalBytesExpectedToWrite exp: Int64) {
print("downloaded \(100*writ/exp)" as AnyObject)
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL){
}
Using Block GET/POST/PUT/DELETE:
let request = NSMutableURLRequest(url: URL(string: "Your API URL here" ,param: param))!,
cachePolicy: .useProtocolCachePolicy,
timeoutInterval:"Your request timeout time in Seconds")
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers as? [String : String]
let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest) {data,response,error in
let httpResponse = response as? HTTPURLResponse
if (error != nil) {
print(error)
} else {
print(httpResponse)
}
DispatchQueue.main.async {
//Update your UI here
}
}
dataTask.resume()
Working fine for me.. try it 100% result guarantee
Solution 4 - Ios
This problem is caused by URLSession has two dataTask methods
open func dataTask(with request: URLRequest, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Swift.Void) -> URLSessionDataTask
open func dataTask(with url: URL, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Swift.Void) -> URLSessionDataTask
The first one has URLRequest as parameter, and the second one has URL as parameter, so we need to specify which type to call, for example, I want to call the second method
let task = URLSession.shared.dataTask(with: url! as URL) {
data, response, error in
// Handler
}
Solution 5 - Ios
In my case error was in NSURL
let url = NSURL(string: urlString)
In Swift 3 you must write just URL:
let url = URL(string: urlString)
Solution 6 - Ios
Tested xcode 8 stable version ; Need to use var request variable with URLRequest() With thats you can easily fix that (bug)
var request = URLRequest(url:myUrl!) And
let task = URLSession.shared().dataTask(with: request as URLRequest) { }
Worked fine ! Thank you guys, i think help many people. !
Solution 7 - Ios
For Swift 3 and Xcode 8:
var dataTask: URLSessionDataTask?
if let url = URL(string: urlString) {
self.dataTask = URLSession.shared.dataTask(with: url, completionHandler: { (data, response, error) in
if let error = error {
print(error.localizedDescription)
} else if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 {
// You can use data received.
self.process(data: data as Data?)
}
})
}
}
//Note: You can always use debugger to check error
Solution 8 - Ios
In swift 3 the compiler is confused by the function signature. Specifying it will clear the error. Also convert the url string to type URL. The following code worked for me.
let urlString = "http://bla.com?batchSize="
let pathURL = URL(string: urlString)!
var urlRequest = URLRequest(url:pathURL)
let session = URLSession.shared
let dataTask = session.dataTask(with: urlRequest as URLRequest) { (data,response,error) in
Solution 9 - Ios
Short and concise answer for Swift 3:
guard let requestUrl = URL(string: yourURL) else { return }
let request = URLRequest(url:requestUrl)
URLSession.shared.dataTask(with: request) {
(data, response, error) in
...
}.resume()
Solution 10 - Ios
// prepare json data
let mapDict = [ "1":"First", "2":"Second"]
let json = [ "title":"ABC" , "dict": mapDict ] as [String : Any]
let jsonData : NSData = NSKeyedArchiver.archivedData(withRootObject: json) as NSData
// create post request
let url = NSURL(string: "http://httpbin.org/post")!
let request = NSMutableURLRequest(url: url as URL)
request.httpMethod = "POST"
// insert json data to the request
request.httpBody = jsonData as Data
let task = URLSession.shared.dataTask(with: request as URLRequest){ data,response,error in
if error != nil{
return
}
do {
let result = try JSONSerialization.jsonObject(with: data!, options: []) as? [String:AnyObject]
print("Result",result!)
} catch {
print("Error -> \(error)")
}
}
task.resume()
Solution 11 - Ios
To load data via a GET request you don't need any URLRequest (and no semicolons)
let listUrlString = "http://bla.com?batchSize=" + String(batchSize) + "&fromIndex=" + String(fromIndex)
let myUrl = URL(string: listUrlString)!
let task = URLSession.shared.dataTask(with: myUrl) { ...
Solution 12 - Ios
let task = URLSession.shared.dataTask(with: request as URLRequest, completionHandler: { data,response,error in
if error != nil{
print(error!.localizedDescription)
return
}
if let responseJSON = (try? JSONSerialization.jsonObject(with: data!, options: [])) as? [String:AnyObject]{
if let response_token:String = responseJSON["token"] as? String {
print("Singleton Firebase Token : \(response_token)")
completion(response_token)
}
}
})
task.resume()
Solution 13 - Ios
Xcode 10.1 Swift 4
This worked for me:
let task: URLSessionDataTask = session.dataTask(with: request as URLRequest) { (data, response, error) -> Void in
...
The key was adding in the URLSessionDataTask type declaration.
Solution 14 - Ios
For me I do this to find,
let url = URL(string: urlString)
URLSession.shared.dataTask(with: url!) { (data, response, error) in ...}
Can't use
"let url = NSURL(string: urlString)