Communication with fragment from activity runtime (after getting user input) - android-fragments

Question

I have FAB and TabLayout with viewpager in mainAcitivty. I want to update fragment of viewpager when user provide input by FAB. Trying to send data via Bundle but always Bundle is null while receiving from fragment.
I think my problem is in receiving data. To which fragment method I should use to receive data?
Here is my MainActivity
package com.example.shahalam.rvfabvptl;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.TabLayout;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
EditText title, description;
FloatingActionButton fab;
ViewPager mPager;
TabLayout tabLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mPager = findViewById(R.id.viewPager);
tabLayout = findViewById(R.id.tabLayout);
fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder mBuilder = new AlertDialog.Builder(MainActivity.this);
View mView = getLayoutInflater().inflate(R.layout.dialog_box,null);
title = mView.findViewById(R.id.titleDialogBox);
description = mView.findViewById(R.id.descriptionDialogBox);
Button btnOK = mView.findViewById(R.id.btnOk);
mBuilder.setView(mView);
final AlertDialog dialog = mBuilder.create();
dialog.show();
btnOK.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FragmentManager fm = getSupportFragmentManager();
final FragmentTransaction ft = fm.beginTransaction();
final FragmentOne fragOne = new FragmentOne();
Bundle mBundle = new Bundle();
mBundle.putString("title", title.getText().toString());
mBundle.putString("description", description.getText().toString());
//PASS OVER THE BUNDLE TO OUR FRAGMENT
FragmentOne myFragment = new FragmentOne();
myFragment.setArguments(mBundle);
ft.add(R.id.linearLayoutFragmentOne,fragOne);
ft.commit();
dialog.cancel();
}
});
}
});
ViewPagerAdapter pagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
mPager.setAdapter(pagerAdapter);
tabLayout.setupWithViewPager(mPager);
}
}
And here is my Fragment class:
package com.example.shahalam.rvfabvptl;
import android.app.Activity;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class FragmentOne extends Fragment {
public FragmentOne() {
}
RecyclerView fragOneRecyclerView;
List<MyDataModel> myDataModels = new ArrayList<>();
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_one,container,false);
fragOneRecyclerView = view.findViewById(R.id.fragmentOneRecyclerView);
fragOneRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
final RecyclerViewAdapter adapterFragmentOne = new RecyclerViewAdapter(getContext(),myDataModels);
fragOneRecyclerView.setAdapter(adapterFragmentOne);
Bundle mBundle =getArguments();
String title="if Bundle is null", description="No description";
if (mBundle != null) {
title = this.getArguments().getString("title");
description = this.getArguments().getString("description");
}
MyDataModel mOne4 = new MyDataModel(title,description);
myDataModels.add(mOne4);
adapterFragmentOne.notifyDataSetChanged();
return view;
}
}

Answer 1

You are creating two different objects of your Fragment FragmentOne ,
and setting the bundle to object myFragment and passing another fragment object fragOne in FragmentTransition. which is wrong , use
the below code.
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
FragmentOne fragOne = new FragmentOne();
Bundle mBundle = new Bundle();
mBundle.putString("title", title.getText().toString());
mBundle.putString("description", description.getText().toString());
//PASS OVER THE BUNDLE TO OUR FRAGMENT
fragOne.setArguments(mBundle);
ft.add(R.id.linearLayoutFragmentOne,fragOne);
ft.commit();
dialog.cancel();