如何在Firestore Swift中获取当前用户文档

Question

When user login done successfully, it takes to home screen. When user taps on user icon button will take to user account details page. here i have already in firebase to retrieve data from database.

here is the code is used:

func observeCurrentUser(completion: @escaping (User) -> Void) {
    guard let currentUser = Auth.auth().currentUser else {
        return
    }
    REF_USERS.child(currentUser.uid).observeSingleEvent(of: .value, with: {
        snapshot in
        if let dict = snapshot.value as? [String: Any] {
            let user = User.transformUser(dict: dict, key: snapshot.key)
            print("user::::::\(user)")
            completion(user)
        }
    })

    }

I tried to migrate from firebase to firestore. While running in console output it shows document does not exists. Here is code i used

  func observeCurrentUser(completion: @escaping (User) -> Void) {
    guard let currentUser = Auth.auth().currentUser else {
        return
    }

   if let userId = Auth.auth().currentUser?.uid {
      db.collection("users").document(currentUser.uid)               
          .addSnapshotListener { (snapshot, error ) in

               if let document = snapshot {

               let user = User.transformUser(dict: document.data()!, key: document.documentID)
               completion(user)         

                } else {

                 print("Document does not exist")

               }

    }

Its already done firebase, I want in cloud firestore?

Any help much appreciated pls.

Answer 1

As the documentation says you can query data by using:

    db.collection("cities").document("SF").getDocument { (document, error) in
        if let document = document, document.exists {
           //access data here
        } else {
            print("Document does not exist")
        }
    }

That means, in your case use:

       db.collection("users").document(currentUser.uid)               
          .getDocument { (snapshot, error ) in

               if let document = snapshot {

               let user = User.transformUser(dict: document.data()!, key: document.documentID)
               completion(user)         

                } else {

                 print("Document does not exist")

               }
       }

Let me know how it works out, and I can update my answer with whatever issue might come up.

Kind regards Chris