Need some help with this code challenge

Question

Hey, I'm having difficultly parsing out the instructions for part two of this challenge. I've taken a few attempt, but I think some guidance would be super helpful at this point.

The approach I've take is to have an enum called UIBarButtonStyle for the style of the button which just has done and plain as cases. Then I've created a class called UIBarButtonItem which uses the UIBarButtonStyle for its style options. I've setup the target and action properties as string optionals and initialized them as nil. Then, back in the BarButton enum's button() method, I've setup a switch statement to initialize the two styles of the buttons with the correct titles.

Not sure where I went wrong - probably more ways than one. Thanks in advance for the help!

buttons.swift

// Example of UIBarButtonItem instance
// let someButton = UIBarButtonItem(title: "A Title", style: .plain, target: nil, action: nil)

enum UIBarButtonStyle {
    case done
    case plain
}

class UIBarButtonItem {
    let title: String
    let style: UIBarButtonStyle
    let target: String?
    let action: String?

    init(title: String, style: UIBarButtonStyle, target: String?, action: String?) {
        self.title = "A title"
        self.style = .plain
        self.target = nil
        self.action = nil
    }
}


enum BarButton {
    case done(title: String)
    case edit(title: String)

    func button() -> UIBarButtonItem {
        switch self {
        case BarButton.done: return UIBarButtonItem.init(title: "Done", style: .done, target: nil, action: nil)
        default: return UIBarButtonItem.init(title: "Edit", style: .plain, target: nil, action: nil)
        }
    }
}

let done = BarButton.done(title: "Save")
let button = done.button()

Answer 1 · 2018-05-29T22:30:09Z

May 29, 2018 10:30pm

Hi Brent,

First, you don't need to redefine the UIBarButtonItem class, so you can delete that whole block of code.

Inside your button() method, you want the title to be set to whatever the user specifies when they create a BarButton instance, not hardcode "Done" and "Edit".

The way that you access the title property is by declaring a temporary constant in your case statement:

case BarButton.done(let title)

Then you you can just pull the value from title when completing your initialiser.

Note that this only works for specified cases, you can't use this approach with default. That's not a problem because the Swift compiler knows that the only possible cases in an enum are the ones that are enumerated. So if you have a branch in your switch statement for every case you don't need a default.

Hope that helps

Alex

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Brent Caswell

Brent Caswell

Need some help with this code challenge

1 Answer

Alex Koumparos

Alex Koumparos