More detail on .backgroundTask(.urlSession("isStormy")) shown at 11:50

I too wonder how do we get at the downloaded data from the background task?

The URLSessionDownloadTask documentation says that "Download tasks directly write the server’s response data to a temporary file…", but it does not explain how to find out where this file lives once the download is completed by the new SwiftUI backgroundTask API.

I would also really like to know this! All I can think of is getting all the tasks from the urlSession and iterating through them.

I ended up doing the below, which works but seems very fragile in case there is more than one download in progress for the URL session.

.backgroundTask(.urlSession("isStormy")) {
    let session = …  // A stored URL session, with the identifier "isStormy"
    session.getAllTasks { tasks in
        for task in tasks {
            if task.state == .suspended || task.state == .canceling { continue }
            // NOTE: It seems the task state is .running when this is called, instead of .completed as one might expect.
                
            if let dlTask = task as? URLSessionDownloadTask {
                if let url = dlTask.response?.url {
                    if let data = try? Data(contentsOf: url) {
                        // Parse the data here.
                    }
                }
            }
        }
    }
}

On a related note, in my use on iOS 16 beta 3, the new SwiftUI backgroundTask API only gets invoked about 65% of the time when I start a background download, as compared to 100% when using the URLSessionDownloadDelegate method below.

func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
    if let data = try? Data(contentsOf: location) {
        // Parse the data here.
    }
}