Can't get asyncProgressHandler to work with UI components

[dduan]

Can't get asyncProgressHandler to work with UI components

[dduan]

Hi @alperkal, thanks!

Let's see, does the progress view update if you set it on a timer? Something like this

var percent: Double = 0
let timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { _ in
    print(count)
    self.progressView.setProgress(percent, animated: false)
    count += 0.1
}

[alperkal]

yes, progressView does update when triggered via a timer:

        var count = 0.0
        _ = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { _ in
            print(count)
            self.progressView.setProgress(Float(count), animated: false)

            count += 0.1
        }

[alperkal]

BTW, I haven't extracted the code from an existing big project. That was the most basic view Controller running in a clean project.

import UIKit
import Just
class ViewController: UIViewController {

    @IBOutlet weak var progressView: UIProgressView!
    @IBOutlet weak var button: UIButton!

    @IBAction func buttonClicked(_ sender: AnyObject) {
        let sampleFile = Bundle.main.url(forResource: "sample", withExtension: "jpg")!
        Just.post("https://httpbin.org/post",
                                     files:["sample": .url(sampleFile, nil)],
                                     asyncProgressHandler:{ p in
                                        print(p.percent)
                                        DispatchQueue.main.async(execute: {
                                            self.progressView.setProgress(p.percent, animated: false)
                                        })
            })
       print("Complete!!")
    }
}

[alperkal]

ok, I got it working finally. I don't know why it only works like this:

 Just.post("https://httpbin.org/post",
                                     files:["sample": .url(sampleFile, nil)],
                                     asyncProgressHandler:{ p in
                                        print(p.percent)
                                        DispatchQueue.main.async(execute: {
                                            self.progressView.setProgress(p.percent, animated: false)
                                        })

        }){ r in
         print(r.ok)
        }

Looks like UI gets updates only if the call is issued asychronously

[dduan]

When Just work synchronously, it needs to block on current thread. If it blocks on the main thread, then any other operation dispatched onto the main thread won't execute until the network is finished. The print statement works because it's not on main thread.