CODEWITHSUNDEEP
androidfirebasekotlinfirebase-realtime-databasekotlin-null-safety
pra9
pra9

Reputation: 49

Only safe call allowed error when EditText is used to send string to firebase in android studio

I am new to Firebase. I have made a simple project which sends user strings to Realtime Database in Firebase. For input, I have used the EditText view. Here is my main activity. username is the id of EditText View

package com.example.firebase
import...

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding
    private lateinit var database: DatabaseReference
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.Remote.setOnClickListener {


            val name = binding.username.text.toString() //Error on this line
            database = FirebaseDatabase.getInstance().getReference("Users")
            val User = User(name)
            database.child(name).setValue(User).addOnSuccessListener {
                binding.username.text.clear() //And This Line
                Toast.makeText(this,"Sucess", Toast.LENGTH_SHORT).show()
            }.addOnFailureListener {
                Toast.makeText(this,"Failed", Toast.LENGTH_SHORT).show()
            }
        }

After Building following error is shown on the commented line of code:

Only safe (?.) or non-null asserted (!!.) calls are allowed on a nullable receiver of type EditText.

It works fine if I direct enter a string instead of using EditText View. Can someone help me with this?

Upvotes: 1

Views: 41

Answers (2)

Alex Mamo
Alex Mamo

Reputation: 139019

It looks like your username EditText object is null. So there are two ways in which you solve this problem:

  1. Use safe call (?.)

     val name = binding.username?.text.toString()
 //                         👆

  2. Use a non-null asserted (!!.)

     val name = binding.username!!.text.toString()
 //                         👆

See more info inside the Kotlin documentation regarding null safety.

Upvotes: 2

cactustictacs
cactustictacs

Reputation: 19592

Do you have different versions of that layout file (e.g. portrait/landscape, small screen, different API level etc)? Check you have an EditText with an ID of username in all of them - if it's missing from some variations, the generated binding class makes that property nullable, since it might not be present (depending on which version of the layout file was inflated)

Upvotes: 0

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