How to use Realm with SwiftUI

Question

I have been trying to figure out how to use Realm with SwiftUI. The problem is that SwiftUI and Realm both have a List type. When you import SwiftUI into your Realm model to make the class a BindableObject and try to create a Realm List property there is an error.

Is it possible to use an instance of the Realm object model and make it a BindableObject in SwiftUI?

Answer 1

Sure, it's very simple, use the module identifier as prefix like this :

let members = RealmSwift.List<Member>()

Now to the second part of your question. It's easy to encapsulate a Realm object (or list, or resultset) in an BindableObject :

final class DBData: BindableObject  {

    let didChange = PassthroughSubject<DBData, Never>()

    private var notificationTokens: [NotificationToken] = []    
    var posts = Post.all

    init() {
        // Observe changes in the underlying model
        self.notificationTokens.append(posts.observe { _ in
            self.didChange.send(self)
        })

        self.notificationTokens.append(Message.all.observe { _ in
            self.didChange.send(self)
        })
    }
}

If you "link" a DBData instance to a SwiftUI View by either using @ObjectBinding or @EnvironmentObject the UI will be refreshed and the new value for posts (in our example here) will be available each time the underlying realm changes.