How to pass data to Activity itself after the camera is called?

Question

I have a Activity with a EditText and a Button. When the button is clicked, the typed text is saved in a Activity and the camera is opened with the method startActivityForResult().

When the user takes the photo and clicks save, the method onActivityResult() is called but the attribute is null.

I researched about and found that depending on some settings can prevent the Activity to be destroyed, but should only be used as a last resort. I then followed the most recommended way and none of the techniques I read on Stackoverflow (except SharedPreferences) worked out.

Below is what I tried:

package cadastro.caelum.com.br.testfragment;

import android.app.Activity;
import android.app.FragmentManager;
import android.content.Intent;
import android.os.PersistableBundle;
import android.provider.MediaStore;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends ActionBarActivity {

    private String parameter;
    private RetainedFragment dataFragment;
    private static final int CONFIGURATION_CHANGE = 1335;
    private static final String EXTRA_KEY = "extrakey";
    private static final String SHARED_KEY = "sharedkey";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // find the retained fragment on activity restarts
        FragmentManager fm = getFragmentManager();
        dataFragment = (RetainedFragment) fm.findFragmentByTag("data");

        // create the fragment and data the first time
        if (dataFragment == null) {
            // add the fragment
            dataFragment = new RetainedFragment();
            fm.beginTransaction().add(dataFragment, "data").commit();
            // load the initial value of the String
            dataFragment.setData("My String");
        }

        // the data is available in dataFragment.getData()

        // On button clicked, open the camera for testing cofiguration changes
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // Try to save the typed value at parameter
                EditText editText = (EditText) findViewById(R.id.edit);
                parameter = editText.getText().toString();
                // Open the camera
                Intent openCamera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                openCamera.putExtra(EXTRA_KEY, editText.getText().toString());
                startActivityForResult(openCamera, MainActivity.CONFIGURATION_CHANGE);
            }
        });

    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // store the data in the fragment
        // saves the EditText's value into the fragment's data
        EditText edit = (EditText)findViewById(R.id.edit);
        dataFragment.setData(edit.getText().toString());
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == CONFIGURATION_CHANGE){
            if(resultCode == Activity.RESULT_OK){
                // Try to get the fragment String
                String string = dataFragment.getData();
                if(string == null){
                    Log.i("happens", "fragment string is null");
                }else {
                    Log.i("happens", "fragment string = "+string);
                }
                // Try to get the extras String
                Bundle extras = data.getExtras();
                string = extras.getString(EXTRA_KEY);
                if(string == null){
                    Log.i("happens", "extra string is null");
                }else {
                    Log.i("happens", "extra string = "+string);
                }
                // Try to get the parameter String
                string = parameter;
                if(string == null){
                    Log.i("happens", "parameter string is null");
                }else {
                    Log.i("happens", "parameter string = "+string);
                }
            }
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        super.onSaveInstanceState(outState, outPersistentState);
        outState.putString("myName", "Felipe");
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        EditText edit = (EditText) findViewById(R.id.text);
        String string = savedInstanceState.getString("myName");
        if(string==null){
            Log.i("happens", "bundle string is null");
        }else {
            edit.setText(string);
            Log.i("happens", "bundle string = " +string);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

And the class RetainedFragment:

package cadastro.caelum.com.br.testfragment;

import android.app.Fragment;
import android.os.Bundle;

/**
 * Created by WindowsLipe on 05/08/2015.
 */
public class RetainedFragment extends Fragment {

    // data object we want to retain
    private String data;

    // this method is only called once for this fragment
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // retain this fragment
        setRetainInstance(true);
    }

    public void setData(String data) {
        this.data = data;
    }

    public String getData() {
        return data;
    }

}

The logcat was the following

08-06 13:22:23.059  20736-20736/cadastro.caelum.com.br.testfragment I/happens﹕ bundle string is null
08-06 13:22:23.059  20736-20736/cadastro.caelum.com.br.testfragment I/happens﹕ fragment string is null
08-06 13:22:23.069  20736-20736/cadastro.caelum.com.br.testfragment I/happens﹕ extra string is null
08-06 13:22:23.069  20736-20736/cadastro.caelum.com.br.testfragment I/happens﹕ parameter string is null

Answer 1

The simplest way to persist a value during Activity destruction/recreation is to do the override of the method onSaveInstanceState() and keep this value in Bundle passed to him.

private String valor;
@Override
public void onSaveInstanceState(Bundle bundle)
{
    super.onSaveInstanceState(bundle);
    bundle.putString("valor", valor);
}  

This value can then be recovered, in the method onCreate(), at the time when Activity is recreated.

public void onCreate(Bundle savedInstanceState)
{
    if (savedInstanceState != null){

        valor = savedInstanceState.getString("valor");
    }

}