Firestore Swift update text realtime - swift

Question

I have this way of collecting information.
struct MainText {
var mtext: String
var memoji: String
}
class MainTextModel: ObservableObject {
#Published var maintext : MainText!
init() {
updateData()
}
func updateData() {
let db = Firestore.firestore()
db.collection("maintext").document("Main").getDocument { (snap, err) in
if err != nil{
print((err?.localizedDescription)!)
return
}
let memoji = snap?.get("memoji") as! String
let mtext = snap?.get("mtext") as! String
DispatchQueue.main.async {
self.maintext = MainText(mtext: mtext, memoji: memoji)
}
}
}
}
And such a way of displaying.
#ObservedObject private var viewModel = MainTextModel()
self.viewModel.maintext.memoji
self.viewModel.maintext.mtext
How can I update online without rebooting the view?

Answer 1

Instead of using getDocument, which only gets the document once and doesn't return updates, you'll want to add a snapshot listener.
Here's the Firestore documentation for that: https://firebase.google.com/docs/firestore/query-data/listen
In your case, you'll want to do something like:
db.collection("maintext").document("Main")
.addSnapshotListener { documentSnapshot, error in
guard let document = documentSnapshot else {
print("Error fetching document: \(error!)")
return
}
guard let data = document.data() else {
print("Document data was empty.")
return
}
if let memoji = data["memoji"] as? String, let mtext = data["mtext"] as? String {
self.maintext = MainText(mtext: mtext, memoji: memoji)
}
}