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Finishing Sync

We have a problem: while syncing habits we're using our user id, but not while syncing our days. From the sync config code, these are the subscriptions we're adding:

SyncContentView.swift
                    subs.append(QuerySubscription<Days>(name: "user_days", query: { 
                        $0.ownerId == user.id
                    }))
                    subs.append(QuerySubscription<Day>())

                    subs.append(QuerySubscription<Habits>(name: "user_habits", query: {
                        $0.ownerId == user.id
                    }))
                    subs.append(QuerySubscription<Habit>())

When we add a Day we never set the ownerId because our model class Day doesn't have it. So when we insert a new Day it will appear for all users, as we're getting Day from all users, because we're not restricting the sync here:

SyncContentView.swift
                    subs.append(QuerySubscription<Day>())

So we need to do two things:

  • subscribe just to our Days
  • add the ownnerId when we create a new Day

Fixing the model: remove Days class​

Let's get rid of Days, as we don't really use that class for anything.

Add ownerId field to Day class​

We;ll add the ownerId field to the Day class.

Day.swift
import Foundation
import RealmSwift

public class Day: Object, ObjectKeyIdentifiable {
    @Persisted(primaryKey: true) var _id: ObjectId

    @Persisted var date = Date()
    @Persisted var habits = RealmSwift.List<Habit>()

    @Persisted var ownerId = ""

    // ... same as before

Remove sync on Days and add sync info to Day​

We'll delete the sync subscription on Days (as we just deleted that class) and add the correct subscription for Day.

SyncContentView.swift
        if let foundSubscription = subs.first(named: "user_days") {
            return
        } else {
            subs.append(QuerySubscription<Day>(name: "user_days", query: {
                $0.ownerId == user.id
            }))

            subs.append(QuerySubscription<Habits>(name: "user_habits", query: {
                $0.ownerId == user.id
            }))
            subs.append(QuerySubscription<Habit>())
        }

Set ownerId while creating a new Day​

DaysView.swift
    let day = Day.createDayWithHabitsInRealm(realm: realm)

    day.ownerId = realm.syncSession?.parentUser()?.id ?? ""
    try? realm.write({
        $days.append(day)
    })

Add ownerId when creating the initial set of Habits​

MainView.swift
    ProgressView()
        .onAppear {
            let habits = Habits()
            habits.ownerId = realm.syncSession?.parentUser()?.id ?? ""
            $allHabitGroups.append(habits)
        }

Testing it​

Now if we run the app new days are not appearing in other users' apps.