How to make a network request wait for an internet connection using waitsForConnectivity

Swift version: 5.1

Paul Hudson @twostraws October 27th 2019

If you use URLSession to make a data task while the user has no internet connection, your request will fail immediately and report an error. However, if you create your session with the waitsForConnectivity configuration option set to true, then the system will automatically wait some time to see if connectivity becomes available before trying the request.

For example, this creates a data task that fetches a URL only when internet connectivity is available:

let config = URLSessionConfiguration.default
config.waitsForConnectivity = true

URLSession(configuration: config).dataTask(with: yourURL) { data, response, error in
    if let error = error {
        print(error.localizedDescription)
    } ei

    // use your data here
}.resume()

By default, the system will wait seven days to see if internet connectivity becomes available, but you can control that with the timeoutIntervalForResource property on your configuration. For example, this will ask the system to wait 60 seconds: