Swipe gesture not updating VC?

Question

Created Oct ’20

Replies 3

Boosts 0

Participants 2

I have a swipe gesture to scroll through horses in an array, but the updateHorse() function doesn't work unless I close the VC and load it again. I have looked at countless tutorials and demos but I can't seem to get the VC to refresh, even though the horseIndex is updating correctly. I would like it to update after the swipe gesture is used, maybe even with the sideways animation (even though it is the same VC, just changing the data displayed)

model

Code Block var currentHorse = myHorses[horseIndex]  
var horseIndex = 0
var horseNumber = countHorses()
func countHorses() -> Int {
    myHorses.count
}
var myHorses = [
    Horse(name: "Donnerhall", idNumber: 1, gender: "Stallion"),
	Horse(name: "Mischa", idNumber: 2, gender: "Mare"),
	Horse(name: "Selena", idNumber: 3, gender: "Mare"),
	Horse(name: "Celeste", idNumber: 4, gender: "Mare")
]

Code Block @IBAction func swipeRight(_ sender: Any) {
        if horseIndex < horseNumber {
            horseIndex -= 1
            print("previous horse")
        }
        if horseIndex == horseNumber {
            horseIndex -= 1
            print("previous horse")
        }
        if horseIndex == -1 {
            horseIndex = horseNumber
            print("ran out of horses")
        }
updateHorse()
}

update function

Code Block 		func updateHorse(){
        horseNameOutlet.text = currentHorse.name
		horseGenderOutlet.text = currentHorse.gender

Answered by imey in 641396022

Thanks, that worked! I knew it had to recompute somehow, but thought it was enough to just use the updateHorse() function. I ended up putting the recalculation at the end of the IBAction to keep it clean

Code Block           @IBAction func swipeRight(_ sender: Any) {
        if horseIndex < horseNumber {
            horseIndex -= 1
        }
        if horseIndex == horseNumber {
            horseIndex -= 1
        }
        if horseIndex == -1 {
            horseIndex = horseNumber
        }
        
        currentHorse = myHorses[horseIndex]
        updateHorse()
    }

Boost

Answer 1

Claude31 OP

Oct ’20

With this
var currentHorse = myHorses[horseIndex]
currentHorse is not updated unless you recompute

You should make it a computed var (I assume class is Horse)

Code Block var currentHorse : Horse {
	return  myHorses[horseIndex]  
}

Another way is to do it in swipe

Code Block @IBAction func swipeRight(_ sender: Any) {
        if horseIndex < horseNumber {
            horseIndex -= 1
		    currentHorse = myHorses[horseIndex]
            print("previous horse")
        }
        if horseIndex == horseNumber {
            horseIndex -= 1
		    currentHorse = myHorses[horseIndex]
            print("previous horse")
        }
        if horseIndex == -1 {
            horseIndex = horseNumber
            print("ran out of horses")
        }
updateHorse()
}

0

Answer 2

imey OP

Oct ’20

Accepted Answer

Thanks, that worked! I knew it had to recompute somehow, but thought it was enough to just use the updateHorse() function. I ended up putting the recalculation at the end of the IBAction to keep it clean

Code Block           @IBAction func swipeRight(_ sender: Any) {
        if horseIndex < horseNumber {
            horseIndex -= 1
        }
        if horseIndex == horseNumber {
            horseIndex -= 1
        }
        if horseIndex == -1 {
            horseIndex = horseNumber
        }
        
        currentHorse = myHorses[horseIndex]
        updateHorse()
    }

0

Answer 3

Claude31 OP

Oct ’20

Thanks for the feedback.
But it would have been more correct to mark my answer as correct and not your use of it.

Good continuation.

0