How to iterate/foreach array in SwiftUI

Question

I have this array of dictionaries.

let deckColors = [
    ["name": "blue", "desc": "desc1"],
    ["name": "yellow", "desc": "desc2"],
]

And my view:

struct ContentView: View {
    var body: some View {
        ForEach(0 ..< deckColors.count) {value in
            Text(deckColors[value]["name"])
        }
    }
}

How can I make it work? Currently getting this error: Protocol type Any cannot conform to StringProtocol because only concrete types can conform to protocols

Rob Napier · Accepted Answer · 2020-02-17 00:17:52Z

14

This seems a very complex way to implement a struct:

struct DeckColor {
    var name: String
    var desc: String
}

let deckColors = [
    DeckColor(name: "blue", desc: "desc1"),
    DeckColor(name: "yellow", desc: "desc2")
]

struct ContentView: View {
    var body: some View {
        ForEach(0 ..< deckColors.count) { value in
            Text(deckColors[value].name)
        }
    }
}

The way you've implemented it requires dealing with the case that the dictionary does not include a "name" value. You can do that, but it's uglier and more fragile:

struct ContentView: View {
    var body: some View {
        ForEach(0 ..< deckColors.count) { value in
            Text(deckColors[value]["name"] ?? "default text if name isn't there.")
        }
    }
}

edited Feb 17, 2020 at 0:17

answered Feb 17, 2020 at 0:16

Rob Napier

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Comments

Mahmud Ahsan · Accepted Answer · 2020-02-17 04:56:22Z

7

This works for me

struct ContentView: View {
    let deckColors = [
        ["name": "blue", "desc": "desc1"],
        ["name": "yellow", "desc": "desc2"],
    ]

    var body: some View {
        ForEach(0 ..< deckColors.count, id: \.self) {value in
            Text(String(self.deckColors[value]["name"]!))
        }
    }
}

answered Feb 17, 2020 at 4:56

Mahmud Ahsan

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Comments

tempest_fiend · Accepted Answer · 2020-02-18 19:15:31Z

1

I would put your deck colors into an enum and then iterate on that.

enum DeckColor: String, CaseIterable {
    case blue
    case yellow

    var desc: String {
        switch self {
            case .blue: return "desc1"
            case .yellow: return "desc2"
        }
    }
}

struct ContentView: View {
    var body: some View {
        VStack(alignment: .leading) {
            ForEach(DeckColor.allCases, id: \.self) { color in
                Text(color.rawValue)
            }
        }
    }
}

edited Feb 18, 2020 at 19:15

answered Feb 17, 2020 at 2:31

tempest_fiend

356 bronze badges

7 Comments

Leo Dabus Over a year ago

This would result in displaying the description instead of the color's name

Leo Dabus Over a year ago

I prefer what Rob Napier suggested. But anyways with this approach you would need to declare your enumeration as enum DeckColor: String, CaseIterable { and pass the color rawValue to the Text initializer. Text(color.rawValue)

tempest_fiend Over a year ago

The reason I suggested an enum over a struct is that with a struct, you have to run initialiser code every time your app runs, which gets more and more cumbersome the more ‘deckColors’ there are. If you want to access them throughout your app, you then either have to create them every time, or create a singleton of them. Enum’s give you public access, are static, and give you type-safety.

Leo Dabus Over a year ago

It all depends if OP will need to change them or not. If you have an enumeration this would not be possible.

tempest_fiend Over a year ago

The use of a dictionary from OP indicates that they might be hard-coding all the values in, but you make a very valid point.

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