How to show alert just one time in Swift?

Question

I'm working with iBeacons and want to show alert when the user is near the iBeacon. For this I do:

for closest in beacons as! [CLBeacon] {
        if closest.major == 4660 && closest.minor == 4648 {
            var customIcon:UIImage! = UIImage(named: "location2.png")
            var customColor:UIColor! = UIColor(red: 63/255.0, green: 172/255.0, blue: 236/255.0, alpha: 1)

            var alert = JSSAlertView().show(
                self,
                title: "You're near the beacon!",
                buttonText: "Dismiss",
                color: customColor,
                iconImage: customIcon
            )
            alert.setTextTheme(.Light)
        }
    }

It works, but a problem is that it shows many times, one by one and user cannot Dismiss this alert. It's because of that my app update the location of ibeacon every second for find new ibeacons.

Can I show this alert just one time?

I do the next:

        var flag = 0
        if flag == 0 {
            var alert = JSSAlertView().show(
                self,
                title: "You're near the beacon!",
                buttonText: "Dismiss",
                color: customColor,
                iconImage: customIcon
            )
            alert.setTextTheme(.Light)
        }

but it doesn't work, too

Answer 1

This is an edit to @cream-corn's code

 var shouldShow = true
    for closest in beacons as! [CLBeacon] {
        if closest.major == 4660 && closest.minor == 4648 {

           break
        }
    }
    if (shouldShow == true) {
        var customIcon:UIImage! = UIImage(named: "location2.png")
        var customColor:UIColor! = UIColor(red: 63/255.0, green: 172/255.0, blue: 236/255.0, alpha: 1)

        var alert = JSSAlertView().show(
                self,
                title: "You're near the beacon!",
                buttonText: "Dismiss",
                color: customColor,
                iconImage: customIcon
            )
        alert.setTextTheme(.Light)
        shouldShow = false
    }

Answer 2

You were on the right track with the flag thing. But if you put var flag = 0 inside that method then flag will always be 0.
You have to declare flag in the class, not the function like this:

class myClass {
var flag = 0
    func myFunction() {
        /*more code here...*/
        if flag == 0 {
            var alert = JSSAlertView().show(
                self,
                title: "You're near the beacon!",
                buttonText: "Dismiss",
                color: customColor,
                iconImage: customIcon
            )
            alert.setTextTheme(.Light)
        }
    }
}

Answer 3

Sorry, It seemed i had overlooked the fact that locationManager(_:didRangeBeacons:inRegion:) is called whenever the ranges change. So if you want an alert to happen once you would add a property to your class

var isShowing:Bool = false

then adjust the code to factor in the boolean

for closest in beacons as! [CLBeacon] { 
    if (closest.major == 4660 && closest.minor == 4648) && isShowing == false {    
        var customIcon:UIImage! = UIImage(named: "location2.png") 
        var customColor:UIColor! = UIColor(red: 63/255.0, green: 172/255.0, blue: 236/255.0, alpha: 1) 

        var alert = JSSAlertView().show( 
                        self, 
                        title: "You're near the beacon!", 
                        buttonText: "Dismiss", 
                        color: customColor, 
                        iconImage: customIcon 
                    ) 
        alert.setTextTheme(.Light) 
        isShowing = true 
        break
    } 
}