I have a question about nested classes and such. I have a UIView that is handling the download of JSON data onto the device, and I have a progress bar which shows the user progress. Since I have to wait for the entire download to finish before going on, I implemented a helper class so I can use the trailing closures (found here)
Any who, here is come code:
In my viewDidLoad
@IBOutlet weak var ProgressBar: UIProgressView!
override func viewDidLoad() {
super.viewDidLoad()
ProgressBar.setProgress(0.10, animated: true)
updateCoreStack.needsCMS = true
updateCoreStack.needsSOC = true
updateCoreStack.needsDIN = true
updateCoreStack.progress = ProgressBar
updateCoreStack.beginUpdate{ completion in
//fires when all updates return!
print(completion)
}
}
And now here's the helper class:
...
let updateCoreStack = uCoreStack()
class uCoreStack {
var progress:UIProgressView? = nil
var needsCMS = false
var needsDIN = false
var needsSOC = false
func beginUpdate(complete: @escaping (String)->()) {
...
self.progress?.setProgress((self.progress?.progress)! + 0.05, animated: true)
...
}
}
It's possibly noteworthy that beginUpdate may be called more than once, ie, per normal use, beginUpdate may be active 3 times. (If that even matters at all...)
With this implementation, I receive the following error per EVERY progressBar change:
2016-11-21 23:50:34.799607 DemoApp[779:241618] This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes.
Stack:(
0 CoreFoundation 0x000000018505c1d8 + 148
1 libobjc.A.dylib 0x0000000183a9455c objc_exception_throw + 56
2 CoreFoundation 0x000000018505c108 + 0
3 Foundation 0x0000000185c40f0c + 192
4 Foundation 0x0000000185c40c4c + 76
5 Foundation 0x0000000185a8c5dc + 112
6 Foundation 0x0000000185c3f8e8 + 112
7 UIKit 0x000000018aeb5ea0 + 244
8 UIKit 0x000000018aed9d78 + 660
9 UIKit 0x000000018aef0b84 + 108
10 UIKit 0x000000018b3cd7d8 + 276
11 DemoApp 0x0000000100122f70 )
Any thoughts or tips? Thank you in advance.
Bump...
