I am a noob (and my code/model currently will show it so please go easy on me!).

I’m taking a first whack at creating a recipes style (cenotes) app.

So that I can update the data I have a remote json file, so users won't have to reinstall to get the updated data.

The app successfully retrieves and parses the data (that’s a win!), but only when first installed.

It is not subsequently refreshing the data when it is changed online. I have tried using .onAppear and also .refreshable unsuccessfully. I need to delete the App and re-install for it to go and fetch the updated data.

Below are some the redacted versions of my files: Can anybody help? I think that I just have a @StateObject/@EnvironmentObject or something similar incorrect, but can’t spot the error.

Locations.swift

import Foundation

class Locations: ObservableObject {
    @Published var locations = [Location]()
        
    init() {
        load()
    }
    
    func load() {
        let url = URL(string: "https://www.i-love-tulum.com/cenotes/locations.json")!
               URLSession.shared.dataTask(with: url) {(data,response,error) in
                   do {
                       if let d = data {
                           let data = try JSONDecoder().decode([Location].self, from: d)
                           DispatchQueue.main.async {
                               self.locations = data
                           }
                       } else {
                           print("No Data")
                       }
                   } catch {
                       print ("Error")
                   }
               }.resume()
    } }

Location.swift - VM

import Foundation

struct Location: Codable, Identifiable {
    var id: String
    let heroPicture: String
    }

App.swift - The App opens to this tab view

import SwiftUI

@main struct App: App {
    @StateObject var locations = Locations()
    @State private var selection = 1
        
    var body: some Scene {
        WindowGroup {
            TabView (selection:$selection) {
                NavigationView {
                    ListView()
                }
                .tabItem {
                    Image(systemName: "drop.circle")
                    Text("Cenotes")
                } .tag(1)
            }
            .environmentObject(locations)
        }
    } }

ListView.swift - The first selected tab is this view - these locations are not updating after the initial install:

import SwiftUI import MapKit

struct ListView: View {
    @EnvironmentObject var locations: Locations
          
    var body: some View {
        VStack {         
            GeometryReader { geo in
                ScrollView {
                    LazyVStack (alignment: .leading) {
                        ForEach (locations: locations.locations) { location in
                               NavigationLink (
                                    destination: ContentView(location: location),
                                    label: { 
                    Image(location.heroPicture)
                    }
            .navigationTitle("Cenotes")
            .navigationBarTitleDisplayMode(.inline)
    } }

CodePudding user response：

All is well set up and works fine. This here adds two Buttons to the list, to delete all entries and reload again. Maybe that helps.

struct ListView: View {
    @EnvironmentObject var locations: Locations
    
    var body: some View {
        List {
            ForEach (locations.locations) { location in
                NavigationLink {
                    Text("Content View here ...")
                } label: {
                    VStack(alignment: .leading) {
                        Text(location.name).font(.title)
                        Text(location.aka).foregroundColor(.secondary)
                    }
                }
                .navigationTitle("Cenotes")
                .navigationBarTitleDisplayMode(.inline)
            }
        }
        
        .toolbar {
            ToolbarItem(placement: .navigationBarLeading) {
                Button("Delete all") {
                    locations.locations = []
                }
            }
            ToolbarItem(placement: .navigationBarTrailing) {
                Button("Reload") {
                    locations.load()  
                }
            }
        }
    }
}

CodePudding user response：

Try this to reload every time and skip all caches:

UPDATE, now working :)

func load() {
    let url = URL(string: "https://www.i-love-tulum.com/cenotes/locations.json")!
    
    let config = URLSessionConfiguration.default
    config.requestCachePolicy = .reloadIgnoringLocalAndRemoteCacheData
    
    let session = URLSession.init(configuration: config)
    session.dataTask(with: url) {(data,response,error) in
        do {
            if let d = data {
                let data = try JSONDecoder().decode([Location].self, from: d)
                DispatchQueue.main.async {
                    self.locations = data
                }
            } else {
                print("No Data")
            }
        } catch {
            print ("Error")
        }
    }.resume()