How to execute an action if another action doesn't complete within 10 seconds?-CodePudding

I have the following piece of code I want to execute at app startup:

let database = "https://example.com" // A website.
let databaseURL = URL(string: "\(database)")!
        var databaseRequest = URLRequest(url: databaseURL)
        databaseRequest.httpMethod = "GET"
        NSURLConnection.sendAsynchronousRequest(databaseRequest, queue: OperationQueue.main) {(response, data, error) in
            guard let data = data else { return }
            let databaseContents = data
            let databaseFile = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].appendingPathComponent("local.txt")
            do {
                try databaseContents.write(to: databaseFile)
            } catch {
                print(error.localizedDescription)
            }
        }

I want to give this code 10 seconds to run. If it takes longer than 10 seconds, abort it and do something else, like this:

print("ERROR: Could not retrieve list.")
let warningToUser = UIAlertController(title: "Error", message: "We couldn't retrieve your preferences, so they have been reset to default values. We will try again next tine you launch this app.", preferredStyle: .alert)
warningToUser.addAction(UIAlertAction(title: "OK", style: .default))
self.present(warningToUser, animated: true)

I don't even what to try. Any help is highly appreciated! Thank you!

CodePudding user response：

you need to specify the time interval of the URLrequest. Just put this line in your code databaseRequest.timeoutInterval = 10

CodePudding user response：

You can set timeoutInterval and check the error after timeoutInterval.

    let database = "https://example.com" // A website.
    let databaseURL = URL(string: "\(database)")!
    var databaseRequest = URLRequest(url: databaseURL, timeoutInterval: 10.0)
    databaseRequest.httpMethod = "GET"
    NSURLConnection.sendAsynchronousRequest(databaseRequest, queue: OperationQueue.main) {(response, data, error) in
        if error != nil {
              print("ERROR: Could not retrieve list.")
              let warningToUser = UIAlertController(title: "Error", message: "We couldn't retrieve your preferences, so they have been reset to default values. We will try again next tine you launch this app.", preferredStyle: .alert)
              warningToUser.addAction(UIAlertAction(title: "OK", style: .default))
              self.present(warningToUser, animated: true)
        }else {
              guard let data = data else { return }
              let databaseContents = data
              let databaseFile = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].appendingPathComponent("local.txt")
              do {
                    try databaseContents.write(to: databaseFile)
              } catch {
                    print(error.localizedDescription)
              }
        }
   }