CODEWITHSUNDEEP
iosjsonswiftswiftuipicker
JOKUE2002
JOKUE2002

Reputation: 37

SwiftUI Picker data from JSON not displayed

I have a picker in swiftui, which i need to fill from a json that i'm currently hosting on my mac.

As I'm running the code, the picker displayed stays empty but the data is available (if I click on a button below which prints it).

Here is my code:

Picker (ContentView.swift):

@State var nwm = NetworkManager()

...

Picker("Wähle deine Schule", selection: $selectedSchool) {
    ForEach(0 ..< nwm.schoolList.results.count) {
        Text(self.nwm.schoolList.results[$0].name).tag($0)
    }
}.labelsHidden()

NetworkManager.swift: 

class NetworkManager : ObservableObject {
    var didChange = PassthroughSubject<NetworkManager, Never>()

    var schoolList = SchoolList(results: []) {
        didSet {
            didChange.send(self)
        }
    }

    init() {
        guard let url = URL(string: "http://jonasmacbookpro.local:8083/IOSApp/getDKSchools") else { return }

        URLSession.shared.dataTask(with: url) {
            (data, _, _) in

            let schoolList = try! JSONDecoder().decode(SchoolList.self, from: data!)

            DispatchQueue.main.async {
                self.schoolList = schoolList
            }
        }.resume()
    }
}

School.swift

struct School : Identifiable, Decodable {
    let id = UUID()
    var name : String
    var ort : String
    var link : String
}

struct SchoolList: Decodable {
    var results: [School]
}

Does anyone know, why it isn't working?

Upvotes: 1

Views: 420

Answers (2)

Mac3n
Mac3n

Reputation: 4719

To make the picker refresh is to add a unique id. You can add .id(UUID()) to your Picker and it should be work fine

Upvotes: 0

Asperi
Asperi

Reputation: 257711

Instead of

@State var nwm = NetworkManager()

Use

@ObservedObject var nwm = NetworkManager()

and instead of 

var didChange = PassthroughSubject<NetworkManager, Never>()

var schoolList = SchoolList(results: []) {
    didSet {
        didChange.send(self)
    }
}

use

@Published var schoolList = SchoolList(results: [])

Upvotes: 1

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