I’m doing an basic App for create notes and subnotes in iPhone and show them in Watch. I did the both CRUD but I can’t view the data in Watch. I’m using userDefaults because It’s so simple app.

I tried add NSObject and WCSessionDelegate to my NoteViewModel but doesn’t work. When I start the app, I get ‘WCSessionActivationState(rawValue: 2)’.

Here is my NoteViewModel.swift:

import Combine
import Foundation
import WatchConnectivity

class NoteViewModel: NSObject, WCSessionDelegate, ObservableObject {
    @Published var notes: [Note] = []
    
    func addNote(title: String) {
        let newNote = Note(title: title, subNotes: [])
        notes.append(newNote)
        saveNotes()
    }

    func addSubNote(to note: Note, title: String, content: String) {
        if let index = notes.firstIndex(where: { $0.id == note.id }) {
            let newSubNote = SubNote(title: title, content: content)
            notes[index].subNotes.append(newSubNote)
            saveNotes()
        }
    }

    func removeNote(note: Note) {
        notes.removeAll { $0.id == note.id }
        saveNotes()
    }

    func removeSubNote(from note: Note, subNote: SubNote) {
        if let index = notes.firstIndex(where: { $0.id == note.id }) {
            notes[index].subNotes.removeAll { $0.id == subNote.id }
            saveNotes()
        }
    }

    func updateNote(note: Note, newTitle: String) {
        if let index = notes.firstIndex(where: { $0.id == note.id }) {
            notes[index].title = newTitle
            saveNotes()
        }
    }

    override init() {
        super.init()
        if WCSession.isSupported() {
            WCSession.default.delegate = self
            WCSession.default.activate()
            self.notes = loadNotes()
        }
    }

    func session(
        _ session: WCSession,
        activationDidCompleteWith activationState: WCSessionActivationState,
        error: Error?
    ) {
        if let error = error {
            print("Error al activar la sesión: (error.localizedDescription)")
        } else {
            print("Sesión activada con estado: (activationState)")
        }
    }

    #if os(iOS)
    func sessionDidBecomeInactive(_ session: WCSession) { }

    func sessionDidDeactivate(_ session: WCSession) {
        session.activate()
    }

    func session(_ session: WCSession, didReceiveMessage message: [String : Any], replyHandler: @escaping ([String : Any]) -> Void) {
        if let notesArray = message["notes"] as? [[String: Any]] {
            let decoder = JSONDecoder()
            if let data = try? JSONSerialization.data(withJSONObject: notesArray, options: []),
               let notes = try? decoder.decode([Note].self, from: data) {
                self.notes = notes
                saveNotes()
            }
        }
    }
    #endif

    private func saveNotes() {
        let encoder = JSONEncoder()
        if let encoded = try? encoder.encode(notes) {
            if let defaults = UserDefaults(suiteName: "group.lucasleone.WatchNotesApp") {
                defaults.set(encoded, forKey: "notes")
            }
            sendNotesToWatch(notes: notes)
        }
    }

    private func loadNotes() -> [Note] {
        if let defaults = UserDefaults(suiteName: "group.lucasleone.WatchNotesApp"),
           let savedNotes = defaults.data(forKey: "notes") {
            let decoder = JSONDecoder()
            if let loadedNotes = try? decoder.decode([Note].self, from: savedNotes) {
                return loadedNotes
            }
        }
        return []
    }

    private func sendNotesToWatch(notes: [Note]) {
        let encoder = JSONEncoder()
        if let encoded = try? encoder.encode(notes) {
            let notesDict = try? JSONSerialization.jsonObject(with: encoded, options: []) as? [[String: Any]]
            if WCSession.default.isReachable {
                WCSession.default.sendMessage(["notes": notesDict ?? []], replyHandler: nil, errorHandler: { error in
                    print("Error enviando mensaje: (error.localizedDescription)")
                })
            }
        }
    }
}

And in the watch, I tried this:

struct HomeView: View {
    @StateObject var viewModel = NoteViewModel()

    var body: some View {
        NavigationView {
            List {
                ForEach(viewModel.notes) { note in
                    NavigationLink(
                        destination: NoteDetailView(
                            note: note, viewModel: viewModel)
                    ) {
                        Text(note.title)
                    }
                }
            }
            .navigationTitle("Notas")
        }
    }
}