How to redirect a user to a specific activity in Cloud Firestore?

Question

While Registering an account using Firebase auth I stored emails in 2 categories Teacher and Student. I add emails to Firestore 2 different categories Teacher and Student wi

Answer 1

package com.example.myapplicationomostff

import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.annotation.NonNull
import androidx.appcompat.app.AppCompatActivity
import com.google.android.gms.tasks.OnCompleteListener
import com.google.android.gms.tasks.Task
import com.google.firebase.auth.FirebaseAuth
import com.google.firebase.firestore.DocumentSnapshot
import com.google.firebase.firestore.FirebaseFirestore
import com.google.firebase.firestore.QueryDocumentSnapshot
import com.google.firebase.firestore.QuerySnapshot
import kotlinx.android.synthetic.main.activity_main.*
import kotlinx.android.synthetic.main.activity_registy.*


class MainActivity : AppCompatActivity() {

    var myauth =FirebaseAuth.getInstance()
    var rootRef = FirebaseFirestore.getInstance()
    var usersRef = rootRef.collection("users")






    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        btnlogin.setOnClickListener {
            var email =txtemaillogin.text.toString().trim()
            var password =txtpasslogin.text.toString().trim()
            userlogin(email,password)


            }



        btnregistry.setOnClickListener{


            var intent = Intent(this, chose::class.java)
            startActivity(intent)

        }




        }

    private fun userlogin(email: String, password: String) {
        var query = usersRef.whereEqualTo("email",email)
        query.get().addOnCompleteListener { task ->
            if (task.isSuccessful) {
                for (document in task.getResult()!!) {
                    var email1 = document.getString("email").toString()
                    var password1 = document.getString("password").toString()
                    if(password1 == password
                        && email1 == email
                    ){
                        myauth.signInWithEmailAndPassword(email1, password1).addOnCompleteListener{
                            if(it.isSuccessful){

                                val uid = FirebaseAuth.getInstance().currentUser?.uid
                                if (uid != null) {
                                    usersRef.document(uid).get().addOnCompleteListener { task ->
                                        if (task.isSuccessful) {
                                            val document = task.result
                                            if (document != null) {
                                                if (document.exists()) {
                                                    val type = document.getString("type")
                                                    if (type == "doc") {
                                                        startActivity(Intent(this@MainActivity,docpage::class.java))
                                                    } else if (type == "eng") {
                                                        startActivity(Intent(this@MainActivity, engpage::class.java))
                                                    }else  if (type=="mos"){
                                                        startActivity(Intent(this@MainActivity, chosepage::class.java))


                                                    }
                                                }
                                            }
                                        }
                                    }
                                }



                                Toast.makeText(this,"ok",Toast.LENGTH_LONG).show()
                            }else{
                                Toast.makeText(this,"erorr",Toast.LENGTH_LONG).show()

                            }
                        }
                    }else{
                        Toast.makeText(this,"مش مسجل ف الموقع ",Toast.LENGTH_LONG).show()


}

Answer 2

Using two different collections, one for each type of your users isn't quite a flexible solutions. Another more simpler solution might be:

Firestore-root
   |
   --- users (collection)
        |
        --- uid (document)
        |    |
        |    --- email: "student@email.com"
        |    |
        |    --- password: "********"
        |    |
        |    --- type: "student"
        |
        --- uid (document)
             |
             --- email: "teacher@email.com"
             |
             --- password: "********"
             |
             --- type: "teacher"

See, I have added the type of the user as a property of your user object. Now, to get a user based on the email address, please use the following lines of code:

FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
CollectionReference usersRef = rootRef.collection("users");
Query query = usersRef.whereEqualTo("email", "student@email.com")
query.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<QuerySnapshot> task) {
        if (task.isSuccessful()) {
            for (QueryDocumentSnapshot document : task.getResult()) {
                String email = document.getString("email");
                String password = document.getString("password");
                mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(/* ... */);
            }
        }
    }
});

Once the user is authenticated, to redirect the user to the corresponding activity, please use the following lines of code:

String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
usersRef.document(uid).get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
        if (task.isSuccessful()) {
            DocumentSnapshot document = task.getResult();
            if (document.exists()) {
                String type = document.getString("type");
                if(type.equals("student")) {
                    startActivity(new Intent(MainActivity.this, Student.class));
                } else if (type.equals("teacher")) {
                    startActivity(new Intent(MainActivity.this, Teacher.class));
                }
            }
        }
    }
});