Network request using Combine doesn't execute - ios

Question

I have the following classes that perform a network call -
import SwiftUI
import Combine
struct CoinsView: View {
private let coinsViewModel = CoinViewModel()
var body: some View {
Text("CoinsView").onAppear {
self.coinsViewModel.fetchCoins()
}
}
}
class CoinViewModel: ObservableObject {
private let networkService = NetworkService()
#Published var data = String()
var cancellable : AnyCancellable?
func fetchCoins() {
cancellable = networkService.fetchCoins().sink(receiveCompletion: { _ in
print("inside receive completion")
}, receiveValue: { value in
print("received value - \(value)")
})
}
}
class NetworkService: ObservableObject {
private var urlComponents : URLComponents {
var components = URLComponents()
components.scheme = "https"
components.host = "jsonplaceholder.typicode.com"
components.path = "/users"
return components
}
var cancelablle : AnyCancellable?
func fetchCoins() -> AnyPublisher<Any, URLError> {
return URLSession.shared.dataTaskPublisher(for: urlComponents.url!)
.map{ $0.data }
.receive(on: DispatchQueue.main)
.eraseToAnyPublisher()
}
}
What I want to achieve currently is just to print the JSON result.
This doesn't seem to work, and from debugging it never seems to go inside the sink{} method, therefor not executing it.
What am I missing?
After further investigation with Asperi's help I took the code to a clean project and saw that I have initialized a struct that wraps NSPersistentContainer which causes for some reason my network requests not to work. Here is the code, hopefully someone can explain why it prevented my networking to execute -
import SwiftUI
#main
struct BasicApplication: App {
let persistenceController = BasicApplciationDatabase.instance
#Environment(\.scenePhase)
var scenePhase
var body: some Scene {
WindowGroup {
CoinsView()
}
.onChange(of: scenePhase) { newScenePhase in
switch newScenePhase {
case .background:
print("Scene is background")
persistenceController.save()
case .inactive:
print("Scene is inactive")
case .active:
print("Scene is active")
#unknown default:
print("Scene is unknown default")
}
}
}
}
import CoreData
struct BasicApplciationDatabase {
static let instance = BasicApplciationDatabase()
let container : NSPersistentContainer
init() {
container = NSPersistentContainer(name: "CoreDataDatabase")
container.loadPersistentStores { NSEntityDescription, error in
if let error = error {
fatalError("Error: \(error.localizedDescription)")
}
}
}
func save(completion : #escaping(Error?) -> () = {_ in} ){
let context = container.viewContext
if context.hasChanges {
do {
try context.save()
completion(nil)
} catch {
completion(error)
}
}
}
func delete(_ object: NSManagedObject, completion : #escaping(Error?) -> () = {_ in} ) {
let context = container.viewContext
context.delete(object)
save(completion: completion)
}
}