How to replace setTargetFragment() now that it is deprecated

Question

setTargetFragment() is deprecated in Java, and I don't understand the correct replacement for it as android documentation uses it and is outdated. I believe the FragmentManager is the correct replacement for it. I am using the deprecated setTargetFragment function in my settings Preferences to create multiple preference screens. To do so, I originally followed the guide here which confusingly uses setTargetFragment in the example. Below is my code:

build.gradle (Module: app)
...
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
implementation 'androidx.preference:preference:1.1.1'
...

MainActivity.kt

class MainActivity : AppCompatActivity() {
    private lateinit var settingsButton: ImageButton

    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        settingsButton = findViewById(R.id.settingsButtonMain)
        settingsButton.setOnClickListener {
            settingsClicked()
        }
        ...
    }

    private fun settingsClicked() {
        val settingsIntent = Intent(this, SettingsActivity::class.java)
        startActivity(settingsIntent)
    }
}

SettingsActivity.kt

class SettingsActivity : AppCompatActivity(), PreferenceFragmentCompat.OnPreferenceStartFragmentCallback {
    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        supportFragmentManager.beginTransaction().replace(R.id.settings, SettingsFragment(this)).commit()
        supportFragmentManager.addOnBackStackChangedListener {
            if(supportFragmentManager.backStackEntryCount == 0) {
                title = "App Settings"
            }
        }
        supportActionBar?.setDisplayHomeAsUpEnabled(true)
        ...
    }

    class SettingsFragment(cont: Context) : PreferenceFragmentCompat() {
        private var context1: Context = cont

        override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
            setPreferencesFromResource(R.xml.root_preferences, rootKey)
        }
    }

    class Screen2PreferencesFragment : PreferenceFragmentCompat() {
        override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
            setPreferencesFromResource(R.xml.screen2_preferences, null)
        }
    }

    override fun onPreferenceStartFragment(caller: PreferenceFragmentCompat?, pref: Preference): Boolean {
        val args: Bundle = pref.extras
        val fragment: Fragment = supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
        fragment.arguments = args
        fragment.setTargetFragment(caller, 0) //TROUBLE AREA. WHAT IS THE CORRECT REPLACEMENT HERE?
        supportFragmentManager.beginTransaction().replace(R.id.settings, fragment).addToBackStack(null).commit()
        return true
    }

    override fun onSupportNavigateUp(): Boolean {
        if(supportFragmentManager.popBackStackImmediate()) {
            return true
        }
        return super.onSupportNavigateUp()
    }
}

Jersey

See: Passing results between fragments – Encyclopedist

Answer 1

Include this dependency:

implementation 'androidx.fragment:fragment-ktx:1.3.0-beta01'

Use setFragmentResultListener instead of setTargetFragment():

override fun onPreferenceStartFragment(caller: PreferenceFragmentCompat?, pref: Preference): Boolean {
    val args: Bundle = pref.extras
    val fragment: Fragment = supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
    fragment.arguments = args
    supportFragmentManager.beginTransaction().replace(R.id.settings, fragment).addToBackStack(null).commit()
    
    supportFragmentManager.setFragmentResultListener("requestKey") { key, bundle ->
        if (key == "requestKey") {
            // Get result from bundle
        }
    }
    
    return true
}

And in your fragment that returns a result:

// Insert result in a bundle
setFragmentResult("requestKey", bundle)

Isaiah

setFragmentResultListener is unresolved. I imagine I need to implement an interface? – Jersey

I think I figured it out. Correct me if I am wrong. setFragmentResultListener should actually look like this val result = "result" \n setFragmentResult("requestKey", bundleOf("bundleKey" to result)) \n FragmentResultOwner needs to be implemented and override the classes here (new line doesn't show in comment, so I added \n where one should be) – Jersey

If it's unresolved, add import androidx.fragment.app.setFragmentResultListener. Create a bundle using bundleOf("bundleKey" to result) and add it as a param to setFragmentResult() like it's shown in the answer. – Isaiah

From my testing, this definitely needs 'FragmentResultOwner' implemented. It does not work without or with just the suggested import (which appears to be invalid). I appreciate the help. – Jersey

Answer 2

For the unresolved issue when trying to use setFragmentResult referring to the answer above, you could try using the fragmentManager as follows.

This is for Xamarin:

ParentFragmentManager.SetFragmentResult("requestKey", bundle);

Zaratite

Answer 3

JANUARY 2024

I replaced setTargetFragment with setFragmentResultListener in two DialogFragments (parent and child) and code below is based on that. I think for the ordinary fragments it works the same way.

Gradle:

implementation 'androidx.fragment:fragment-ktx:1.6.2'

onCreateDialog in parent DialogFragment:

Set FragmentResultListener for parentFragmentManager. Remember to launch child fragment using the same fragment manager!

...
parentFragmentManager.setFragmentResultListener("requestKey", this) { key, bundle ->
    val result = bundle.getString("myKey")
    //result is a string passed by child fragment
}

binding.someButton.setOnClickListener {
    val dialog = ChildDialogFragment()
    dialog.show(parentFragmentManager, "someTag")
}
...

Child DialogFragment:

I will pass String value to parent fragment on button click.

binding.someOtherButton.setOnClickListener {
    val stringToPass = "blablabla"
    val bundle = Bundle().apply {
        putString("myKey", result)
    }
    parentFragmentManager.setFragmentResult("requestKey", bundle)
}

Enjoy!

Adventuresome