Question 302944 in Firebase Question posted in
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How can I retrieve the details from a user id from my database in firebase in kotlin?

I am trying to setup a profile page in my project, and I am trying implement a function that when the user clicks the profile tab on the bottom, it will display the info that is stored on my project’s database after being redirected to the profile page.

Here is the code for my profile page:

class User_Activity : AppCompatActivity() {

    private lateinit var binding: ActivityUserBinding
    private lateinit var databaseReference: DatabaseReference
    private lateinit var firebaseAuth: FirebaseAuth
    private lateinit var uid : String
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityUserBinding.inflate(layoutInflater)
        setContentView(binding.root)
        loadUserDetails()

        firebaseAuth = FirebaseAuth.getInstance()

        uid = firebaseAuth.currentUser?.uid.toString()
        databaseReference = FirebaseDatabase.getInstance().getReference("Users")
       

        val LogoutBtn = findViewById<Button>(R.id.logoutBtn)
        LogoutBtn.setOnClickListener {
            val intent = Intent(this@User_Activity, MainActivity::class.java)
            startActivity(intent)
        }

        //navbar redirection
        val addImg: ImageView = findViewById(R.id.navCreate)
        addImg.setOnClickListener {
            val intent = Intent(this@User_Activity, Slam_Activity::class.java)
            startActivity(intent)
        }

        val gotoUser: ImageView = findViewById(R.id.navUser)
        gotoUser.setOnClickListener {
            val intent = Intent(this@User_Activity, User_Activity::class.java)
            startActivity(intent)
        }

        val gotoHome: ImageView = findViewById(R.id.navHome)
        gotoHome.setOnClickListener {
            val intent = Intent(this@User_Activity, Homepage_Activity::class.java)
            startActivity(intent)
        }
    }

here is the function I am trying to implement:

private fun loadUserDetails() {
     //db ref to fetch user info
     val userRef = databaseReference.child(uid)

     userRef
         .addValueEventListener(object: ValueEventListener{
             override fun onDataChange(snapshot: DataSnapshot) {
                 for (usersnapshot in snapshot.children) {
                     //Log.d("FirebaseData", "Snapshot: $snapshot")

                     val email = usersnapshot.child("email").value.toString()
                     val username = usersnapshot.child("username").value.toString()
                     val uid = usersnapshot.child("id").value.toString()

                     //Log.d("FirebaseData", "Email: $email, Username: $username, UID: $uid")

                     binding.profileUID.text = uid
                     binding.profileEmail.text = email
                     binding.profileUsername.text = username
                 }
             }

             override fun onCancelled(error: DatabaseError) {
                 Log.e("FirebaseError", "Error: $error")
             }
         })
 }

This is what my database looks like:

enter image description here

what happens now after clicking the profile tab on the nav bar is that it loops back to the sign in page and when you click the profile tab again, it crashes.

I have tried to do different codes, but I am still getting nothing, even after researching numerous articles. The output should be returning all the data from the current user id.

Tags:

2

Answers


  1. 0

    You’re loading data from /Users/$userId, so the DataSnapshot you get in your onDataChange will have the information for a single user.

    But the code in your onDataChange loops over the child nodes of the data snapshot, as if it gets a list of results. That won’t work, which probably explains the crash.

    The solution is to remove the loop from your onDataChange implementation. Such a loop is only needed when you get a list of results, not when you directly get the snapshot of a single user node.

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  2. 0

    Can you try this one:

    
private fun loadUserDetails() {
    // Check if user is logged in
    val currentUser = firebaseAuth.currentUser
    if (currentUser == null) {
        // Redirect to login activity or handle unauthenticated user
        return
    }

    val userRef = databaseReference.child(currentUser.uid)
    userRef.addListenerForSingleValueEvent(object : ValueEventListener {
        override fun onDataChange(snapshot: DataSnapshot) {
            if (snapshot.exists()) {
                val email = snapshot.child("email").value.toString()
                val username = snapshot.child("username").value.toString()
                val uid = snapshot.child("id").value.toString()

                binding.profileUID.text = uid
                binding.profileEmail.text = email
                binding.profileUsername.text = username
            } else {
                // Handle case where user data does not exist
            }
        }

        override fun onCancelled(error: DatabaseError) {
            Log.e("FirebaseError", "Error: $error")
            // Handle database error
        }
    })
}

    I’ve just added a check if the user is logged in.
    Then I used addListenerForSingleValueEvent instead of addValueEventListener to fetch data once instead of listening for all data changes.

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