I'm trying to fetch subcollection of my users document with code below

    func readData(){
        let userId = Auth.auth().currentUser?.uid
        self.db.collection("users/\(userId)/saved").getDocuments { (snapshot, err) in
            if let err = err {
                print("err")
            }
                if let userId != nil {
                    for document in snapshot!.documents {
                       let docId = document.documentID
                       let cty = document.get("city") as! String
                       let ccode = document.get("code") as! String
                       let countr = document.get("country") as! String
                       print(cty, ccode, countr,docId)
                }
        }
        }

but my code doesn't print anything, I don't understand the problem, documents exsist, see picture below

CodePudding user response：

You're using illegal syntax with the userId check in the snapshot return but the logic flow is the bigger problem. I would recommend you check if the user is signed in before grabbing the subcollection and checking if there is a viable snapshot instead of checking the state of authentication.

func readData() {
    guard let userId = Auth.auth().currentUser?.uid else {
        return
    }
    db.collection("users/\(userId)/saved").getDocuments { (snapshot, error) in
        guard let snapshot = snapshot else {
            if let error = error {
                print(error)
            }
            return
        }
        for doc in snapshot.documents {
            guard let city = doc.get("city") as? String,
                  let code = doc.get("code") as? String,
                  let country = doc.get("country") as? String else {
                      continue // continue document loop
                  }
            let docId = doc.documentID
            print(city, code, country, docId)
        }
    }
}