swift NSTimer userinfo

Question

I'm trying to pass a UIButton with a NSTimer's userinfo. I've read every post on stackoverflow on NSTimers. I'm getting very close but can't quite get there. This post has helped

Swift NSTimer retrieving userInfo as CGPoint

func timeToRun(ButonToEnable:UIButton) {
    var  tempButton = ButonToEnable
    timer = NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: Selector("setRotateToFalse"), userInfo: ["theButton" :tempButton], repeats: false)    
}

the function the timer runs

func setRotateToFalse() {
    println(  timer.userInfo )// just see whats happening

    rotate = false
    let userInfo = timer.userInfo as Dictionary<String, AnyObject>
    var tempbutton:UIButton = (userInfo["theButton"] as UIButton)
    tempbutton.enabled = true
    timer.invalidate()    
}

Answer 1

I realise you've managed to fix this but I thought I would give you a little more information about using NSTimer. The correct way to access the timer object and hence user info is to use it like below. When initialising the timer you can create it like this:

Swift 2.x

NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: Selector("setRotateToFalse:"), userInfo: ["theButton" :tempButton], repeats: false)

Swift 3.x<

Timer.scheduledTimer(timeInterval: 1, target: self, selector:#selector(ViewController.setRotateToFalse), userInfo: ["theButton" :tempButton], repeats: false)

Then the callback looks like this:

func setRotateToFalse(timer:NSTimer) {
    rotate = false
    let userInfo = timer.userInfo as Dictionary<String, AnyObject>
    var tempbutton:UIButton = (userInfo["theButton"] as UIButton)
    tempbutton.enabled = true
    timer.invalidate()    
}

Therefore you don't need to keep a reference to the timer and avoid often nasty global variables where possible. You may run into an issue in swift if your class doesn't inherit from NSObject where it says there is no callback defined but this can be easily fixed by adding @objc at the beginning of the function definition.