CODEWITHSUNDEEP
swiftxcode
Axemasta
Axemasta

Reputation: 843

Can I change outlets using an array, instead of hard coding everything?

I have an app where a user can select a number of different buttons onscreen. When a user selects a button, it turns green and the text will be used in a later view. I am trying to make everything nice and swift by minimising the amount of code I am writing.

Every button is connected to the same action and their identity is determined by their tag. What I have done is created 2 arrays to track the card name and their on/off state. When a card is pressed the cardPressed function is called, this decides whether to turn the card green or white currently (it will do more later).

What I want to do is to perform the colour change in one line of code, instead of 

cardOne.backgroundColor = UIColor.white

I want to do this [#1]

cardList[cardNumber].backgroundColor = UIColor.green

so that my outlet changes depending on the selection made. I would normally just have a massive switch statement that would read like so

switch cardList[cardNumber] {
    case 0:
        cardOne.backgroundColor = UIColor.green
    case 1:
        cardTwo.backgroundColor = UIColor.green
    case 2:
        cardThree.backgroundColor = UIColor.green
    case So on so forth:
        cardInfinity.......
    default:
        break
    }

Obviously when I try to do [#1] I get an error because it is a string, not an outlet connection. What I would like to know, is there anyway to trick xcode into recognising it as an outlet, or better yet have a way to change the outlets I am acting upon in one line of code?

Hopefully I haven't rambled too much and you can understand my thought process! I have included all of the relevant code below, obviously it won't compile. If you have any ideas they would be appreciated, or if I'm being too optimistic and this isnt possible, just let me know :) for now I will be using a big switch statement! (maybe this is useful to me in the future!)

Thanks! 

private let cardList = ["cardOne","cardTwo","cardThree"]

private var cardState = [false, false, false]

//Card functions

private func selectCard(cardNumber: Int){

    cardState[cardNumber] = true

    cardList[cardNumber].backgroundColor = UIColor.green
}

private func deselectCard(cardNumber: Int){

    cardState[cardNumber] = false
    //cardOne.backgroundColor = UIColor.white
}

//Decide which function to perform, based on the card information recieved
private func cardPressed(cardNumber: Int){
    let selectedCardName = cardList[cardNumber]
    let selectedCardState = cardState[cardNumber]

    print("\(selectedCardName)")
    print("\(selectedCardState)")

    switch selectedCardState {
    case true:
        deselectCard(cardNumber: cardNumber)
    case false:
        selectCard(cardNumber: cardNumber)
    }
}

//UI Connections

//Card button actions
@IBAction func buttonPressed(_ sender: UIButton) {
    //Determine which button has been pressed
    //let cardName = sender.currentTitle!
    let cardSelection = sender.tag - 1
    cardPressed(cardNumber: cardSelection)
}

//Card button outlets
@IBOutlet weak var cardOne: UIButton!
@IBOutlet weak var cardTwo: UIButton!

Upvotes: 0

Views: 44

Answers (1)

nathangitter
nathangitter

Reputation: 9777

The solution lies in the wonderful world of object-oriented programming. Instead of using parallel arrays, you can create your own data type to group this data and behavior together.

If you created your own UIButton subclass, you could keep track of whether the button is selected with your own custom property, and make visual modifications as needed.

class CardButton: UIButton {
    var isChosen: Bool = false {
        didSet { backgroundColor = isChosen ? UIColor.green : UIColor.white }
    }
}

If you set the buttons in the storyboard to be your new CardButton type, you can use their isChosen property in code.

Your buttonPressed function could look like this instead:

@IBAction func buttonPressed(_ sender: CardButton) {
    sender.isChosen = !sender.isChosen
}

This would allow you to remove the majority of your existing code, since the data is stored inside each of your buttons.

Upvotes: 1

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