Adding item to recyclerview inside fragment on Notification Click

Question

SCENARIO

I am having 2 fragments inside a View Pager . In one of the fragment I am having a button to generate notification. Notification is generated successfully. Now I want to send some data on notification click back to fragment. For this I am using onNewIntent() method inside activity and from that I called fragment method to pass data back to the fragment.

All this is working fine.

PROBLEM:

After receiving data from notification I am adding it to an arraylist and showing it in RecyclerView . Now main problem is that in this scenario onCreateView() is not called again and due to this issue all the views in the fragment are null which is causing Null Pointer Exception all the time. Is there any way to get view in onResume() or save reference to previous views.

Here is the related code.

Activity onNewIntent() code:

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    intent=getIntent();
    if (intent.hasExtra("notification_data")) {
        Record record = (Record) intent.getSerializableExtra("notification_data");
        FragmentRecords fragmentRecords = new FragmentRecords();
        fragmentRecords.getDataFromIntent(record);
    }

}

Fragment getDataFromIntent method:

    public void getDataFromIntent(Record record){

       DatabaseManager databaseManager=new DatabaseManager(MainActivity.context);
       recordDao = null;
       try {
           recordDao=databaseManager.getDao();
           addData();
       } catch (SQLException e) {
           e.printStackTrace();
       }
       recordArrayList.add(record);
       recordAdapter.notifyDataSetChanged();
   }

initView() method

private void initView(View view){
    btnAddRecords= (Button) view.findViewById(R.id.btn_add_data);
    btnNotification= (Button) view.findViewById(R.id.btn_create_notification);
    recyclerRecords= (RecyclerView) view.findViewById(R.id.rv_list);
    recordArrayList=new ArrayList<>();
    DatabaseManager databaseManager=new DatabaseManager(MainActivity.context);
    recordDao = null;
    try {
        recordDao=databaseManager.getDao();
        addData();
    } catch (Exception e) {
        e.printStackTrace();
    }

addData() method consists of adding static data into the arraylist.

private void addData(){
    recordArrayList.add(new Record("Ram","1234567890","10 years","hello",1L));
    recordArrayList.add(new Record("Rahim","1234567890","12 years","hello",2L));
    recordArrayList.add(new Record("Shyam","1234567890","13 years","hello",3L));
    recordArrayList.add(new Record("Sunder","1234567890","40 years","hello",4L));
    recordArrayList.add(new Record("Demo","1234567890","14 years","hello",5L));
    recordArrayList.add(new Record("Demo1","1234567890","15 years","hello",6L));
    recordArrayList.add(new Record("Demo2","1234567890","16 years","hello",7L));
    for (int i=0;i<recordArrayList.size();i++){
        try {
            recordDao.create(recordArrayList.get(i));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    Toast.makeText(MainActivity.context, recordArrayList.size()+" records added successfully", Toast.LENGTH_SHORT).show();
   setAdapter();
}


private void setAdapter(){
       recordAdapter=new RecordAdapter(MainActivity.context,recordArrayList);
       RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(MainActivity.context);
       recyclerRecords.setLayoutManager(mLayoutManager);
       recyclerRecords.setItemAnimator(new DefaultItemAnimator());
       recyclerRecords.addItemDecoration(new SimpleItemDecorator(5));
       recyclerRecords.setAdapter(recordAdapter);


   }

Error Stacktrace

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setLayoutManager(android.support.v7.widget.RecyclerView$LayoutManager)' on a null object reference at com.testdemo.fragments.FragmentRecords.setAdapter(FragmentRecords.java:134) at com.testdemo.fragments.FragmentRecords.addData(FragmentRecords.java:128) at com.testdemo.fragments.FragmentRecords.getDataFromIntent(FragmentRecords.java:148) at com.testdemo.activities.MainActivity.onNewIntent(MainActivity.java:52) at android.app.Instrumentation.callActivityOnNewIntent(Instrumentation.java:1265) at android.app.Instrumentation.callActivityOnNewIntent(Instrumentation.java:1282) at android.app.ActivityThread.deliverNewIntents(ActivityThread.java:2755) at android.app.ActivityThread.performNewIntents(ActivityThread.java:2773) at android.app.ActivityThread.handleNewIntent(ActivityThread.java:2782) at android.app.ActivityThread.-wrap12(ActivityThread.java) at android.app.ActivityThread$H.h andleMessage(ActivityThread.java:1602) at android.os.Handler.dispatchMessage(Handler.java:111) at android.os.Looper.loop(Looper.java:227) at android.app.ActivityThread.main(ActivityThread.java:6102) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:961) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:822)

Answer 1

As it was pointed out on the comments, you are interacting with a new FragmentRecords instance which isn't started yet instead of using your existing fragment. You should try to retrieve a reference to the existing FragmentRecords instance (maybe through findFragmentByTag method if you are using tags to identify your fragments) and then call the getDataFromIntent on that instance.

I hope it helps.