iOS9 sendSynchronousRequest deprecated

Question

Warning:\'sendSynchronousRequest(_:returningResponse:)\' was deprecated in iOS 9.0: Use [NSURLSession dataTaskWithRequest:completionHandler:] (see NSURLSe

Answer 1

Swift 4 / Xcode 9

If you really want the request to be synchronous like in the deprecated semantics, you can block the main thread with an empty loop on a condition set true by the completion handler:

let request = URLRequest(url: URL(string: "YOUR_URL")!)
let session = URLSession.shared
var gotResp = false

let task = session.dataTask(with: request,
            completionHandler: { data, response, error -> Void in
                // do my thing...
                gotResp = true
            })
task.resume()

// block thread until completion handler is called
while !gotResp {
    // wait
}

print("Got response in main thread")
...

EDIT: or if you prefer to use semaphores like in the Obj-C Nick H247 answer:

let request = URLRequest(url: URL(string: "YOUR_URL")!)
let session = URLSession.shared
let ds = DispatchSemaphore( value: 0 )    
let task = session.dataTask(with: request,
            completionHandler: { data, response, error -> Void in
                // do my thing..., then unblock main thread
                ds.signal()
            })
task.resume()

// block thread until semaphore is signaled
ds.wait()

print("Got response in main thread")
...