Android: Issue trying to pass data between fragments

Question

Im trying to pass some data from a ListFragment to another Fragment. The list shows up fine but when I click on an item in the list, nothing happens, and there is nothing showing up in the log that indicates an error. I'm new to android/java development and trying to wrap my ahead around the different concepts (activities, fragments, bundle, etc). Coming from the iOS/objective C world I see similarities in the concept involved in passing data between 'views' but I guess I'm not fully understanding the android concept.

Anyway, the fragments and layouts are below. Can someone help me to see where I am going wrong? Much appreciated.

Layout for main (fragment_ehschedule.xml) and list view (schedule_info.xml):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent" 
 android:orientation="vertical">

 <EditText android:id="@+id/myFilter" 
  android:layout_width="match_parent"
  android:layout_height="wrap_content" 
  android:ems="10" 
  android:hint="@string/some_hint">
  <requestFocus />
 </EditText>

 <ListView android:id="@android:id/list" 
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" />

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:id="@+id/frameLayout"
    android:padding="6dip" >

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/textViewSessionTime"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:paddingTop="10dip"
            android:paddingBottom="10dip"
            android:text="sessiontime" />

        <TextView
            android:id="@+id/textViewScheduleDate"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="scheduledate"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/textViewSessionName"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:text="sessionname"
            android:textAppearance="?android:attr/textAppearanceMedium" />

    </LinearLayout>

</FrameLayout>

Layout for the fragment detail (fragment_ehschedule_detail.xml) is below:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:padding="10dp">

  <TextView android:id="@+id/sessionname_label"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textSize="25dip"
            android:textStyle="bold"
            android:paddingTop="10dip"
            android:paddingBottom="10dip"
            android:textColor="#43bd00"/>

  <TextView android:id="@+id/scheduledate_label"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textColor="#acacac"/>

  <TextView android:id="@+id/sessiontime_label"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textStyle="bold"/>

</LinearLayout>

Class file for main view (EhallSchedFragment2.java) is below:

 public class EhallSchedFragment2 extends ListFragment{

     public static String strDate = null;

     private SQLiteDB sqlite_obj;
     private SimpleCursorAdapter dataAdapter;

      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                 Bundle savedInstanceState) {
             super.onCreateView(inflater, container, savedInstanceState);
             final View v = inflater.inflate(R.layout.fragment_ehschedule, container, false);

    sqlite_obj = new SQLiteDB(getActivity());

    sqlite_obj.open();

    Cursor cursor = sqlite_obj.fetchAllSchedules();

     // The desired columns to be bound
     String[] columns = new String[] {
       SQLiteDB.KEY_SCHEDULEDATE,
       SQLiteDB.KEY_SESSIONNAME,
       SQLiteDB.KEY_SESSIONTIME,
       SQLiteDB.KEY_DESC
     };

     // the XML defined views which the data will be bound to
     int[] to = new int[] { 
       R.id.textViewScheduleDate,
       R.id.textViewSessionName,
       R.id.textViewSessionTime,
       R.id.textViewDesc,
     };

     // create the adapter using the cursor pointing to the desired data 
     //as well as the layout information
     dataAdapter = new SimpleCursorAdapter(
             getActivity(), R.layout.schedule_info, 
               cursor, 
               columns, 
               to,
               0);

     ListView listView = (ListView)v. findViewById(android.R.id.list);
     // Assign adapter to ListView
     listView.setAdapter(dataAdapter);

     listView.setOnItemClickListener(new OnItemClickListener() {
       @Override
       public void onItemClick(AdapterView<?> listView, View view, 
         int position, long id) {
       // Get the cursor, positioned to the corresponding row in the result set
       Cursor cursor = (Cursor) listView.getItemAtPosition(position);

       String exHallScheduleDate = 
                cursor.getString(cursor.getColumnIndexOrThrow("scheduleDate"));
       String exHallSessionName = 
                        cursor.getString(cursor.getColumnIndexOrThrow("sessionName"));
       String exHallSessionTime = 
                        cursor.getString(cursor.getColumnIndexOrThrow("sessionTime"));

       EhallSchedDetailFragment2 myDetailFragment = new EhallSchedDetailFragment2();

       Bundle bundle = new Bundle();

       bundle.putString("scheduleDate", exHallScheduleDate);
       bundle.putString("sessionName", exHallSessionName);
       bundle.putString("sessionTime", exHallSessionTime);

           myDetailFragment.setArguments(bundle);

           FragmentManager fragmentManager = getFragmentManager();

            myDetailFragment.setArguments(bundle);
            FragmentTransaction transaction = fragmentManager.beginTransaction();
            transaction.replace(R.id.frameLayout, myDetailFragment);
            transaction.remove(EhallSchedFragment2.this);

           /*
                * Add this transaction to the back stack. 
                * This means that the transaction will be remembered after it is 
                * committed, and will reverse its operation when later popped off 
                * the stack.
           */
               transaction.addToBackStack(null);

               transaction.commit();

       }
      });


     EditText myFilter = (EditText)v. findViewById(R.id.myFilter);
      myFilter.addTextChangedListener(new TextWatcher() {

       public void afterTextChanged(Editable s) {
       }

       public void beforeTextChanged(CharSequence s, int start, 
         int count, int after) {
       }

       public void onTextChanged(CharSequence s, int start, 
         int before, int count) {
        dataAdapter.getFilter().filter(s.toString());
       }
      });

      dataAdapter.setFilterQueryProvider(new FilterQueryProvider() {
             public Cursor runQuery(CharSequence constraint) {
                 return sqlite_obj.fetchScheduleByDate(constraint.toString());
             }
         });

    return v;
}

}

Class file for detail view (EhallSchedDetailFragment2.java) is below:

 public class EhallSchedDetailFragment2 extends Fragment {

TextView scheduleDateDetail;
TextView sessionNameDetail;
TextView sessionTimeDetail;

@Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {
   View view = inflater.inflate(R.layout.fragment_ehschedule_detail, null);

   scheduleDateDetail = (TextView)view.findViewById(R.id.scheduledate_label);
   sessionNameDetail = (TextView)view.findViewById(R.id.sessionname_label);
   sessionTimeDetail = (TextView)view.findViewById(R.id.sessiontime_label);

       Bundle bundle = getArguments();
          if(bundle != null){
           String schedDateDet = bundle.getString("scheduleDate");
           scheduleDateDetail.setText(schedDateDet);

           String sessNameDet = bundle.getString("sessionName");
           sessionNameDetail.setText(sessNameDet);

           String sessTimeDet = bundle.getString("sessionTime");
           sessionTimeDetail.setText(sessTimeDet);
          }
          return view;
}

}

Answer 1

You basically need four things to get what you need:

1. You need your fragment - call it FragmentA
2. You then define an interface inside that fragment or in its own class file. This interface will have a method that you must call to notify the activity.
3. Then in your activity, you implement the interface and override the method from step 2 above.
4. To notify FragmentB, all you really need to do is call its method inside the method you overrode in step 3.

As mentioned, you should not communicate between fragments directly. Here is a good step by step tutorial on how to do all the above steps:

Communicating between Fragments and Activities

I hope this helped you solve or getting closer to solving your problem.

Answer 2

If you are using a ListFragment, you can do something like this:

 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    mListView = getListView();
    SetClicklListener(mListView);  
  }
 public void SetClicklListener(ListView listView){
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
        int position, long id) {
            //Here you can catch the clicked item
        }
    });
}