How to extract latitude and longitude from firebase whenever they get updated? When i am trying to get it it returns Both the key-value pair, All i need is latest value.

public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;

    databaseReference = FirebaseDatabase.getInstance().getReference("Routes").child("route1").child("Location");
    ValueEventListener valueEventListener = databaseReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {[enter image description here][1]
            String lat = snapshot.child("Latitude").getValue().toString();
            Toast.makeText(ParentsMapActivity.this, lat.toString(), Toast.LENGTH_LONG).show();
        }
    });

CodePudding user response：

The Latitude and Longitude nodes don't contain numeric values, but instead contain a child nodes that contains that value. From the looks of it, the extra child nodes (starting with -M) were generated by calling push(). If you remove that extra push() call, your code can read the values from the resulting data.

CodePudding user response：

As per your requirement, the latest database value from firebase must be obtained to plot on map .In mapsActivity, you can try the this.

override fun onResume() {
    super.onResume()
    //get instance of firebase database
    database = FirebaseDatabase.getInstance().reference
    //look for name from reference
    database.child(getName!!).get().addOnSuccessListener {
        //check that name is available or not if yes then->
        if (it.exists()) {
            val h = Handler()
            h.postDelayed(object : Runnable {
                private var time: Long = 0
                override fun run() {
                    val latitude: Double = it.child("latitude").value.toString().toDouble()
                    //get the long latitude entity value form reference
                    val longitude: Double = it.child("longitude").value.toString().toDouble()
                    //assigning the positions of lat and long
                    position = LatLng(latitude, longitude)
                    mMap.clear()
                    mMap.addMarker(MarkerOptions().position(position).title("$getName"))
                    mMap.moveCamera(CameraUpdateFactory.newLatLng(position))

                    time  = 1000
                    h.postDelayed(this, 1000)
                }
            }, 1000) // 1 second delay (takes millis)
            mMap.animateCamera(CameraUpdateFactory.zoomTo(15f))
        } else Toast.makeText(this, "Location doesn't exist", Toast.LENGTH_SHORT).show()
    }.addOnFailureListener {
        Toast.makeText(this, "Location didn't reach the database", Toast.LENGTH_SHORT).show()
    }
}

The realtime database from the firebase was as given below