How to send data from Activity to Fragment

Question

I know there are many topics about this here. I have also read documentation many times but I can't find the best way to pass data from activity to fragment.

I want to be able to show the results of my Searchable activity in two differents layouts (list and map) using swipe Views with tabs. I have to pass 2 data to the fragments: "currentLocation" which is the current user location and "result" which is a list of objects.

I have omited some parts of my code to make it more understandable.

SearchableActivity.java

public class SearchableActivity extends ActionBarActivity implements TabListener {

    List<PlaceModel> result = new ArrayList<PlaceModel>();
    private SearchView mSearchView;
    private String currentLocation;

    AppSectionsPagerAdapter mAppSectionsPagerAdapter;
        ViewPager mViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_searchable);

    final ActionBar actionBar = getSupportActionBar();
    actionBar.setHomeButtonEnabled(true);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());

    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mAppSectionsPagerAdapter);
    mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            actionBar.setSelectedNavigationItem(position);
        }
    });

    actionBar.addTab(actionBar.newTab().setText("List").setTabListener(this));
    actionBar.addTab(actionBar.newTab().setText("Map").setTabListener(this));

    // get currentLocation here

    handleIntent(getIntent());
}

@Override
protected void onNewIntent(Intent intent) {
    handleIntent(intent);
}

private void handleIntent(Intent intent) {

    if (Intent.ACTION_SEARCH.equals(intent.getAction())) {

        final String query = intent.getStringExtra(SearchManager.QUERY);

        // get result here
    }
}

@Override
public void onTabReselected(Tab arg0, FragmentTransaction arg1) {
    // TODO Auto-generated method stub

}

@Override
public void onTabSelected(Tab tab, FragmentTransaction arg1) {
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab arg0, FragmentTransaction arg1) {
    // TODO Auto-generated method stub

}

}

PlaceListFragment.java

public class PlaceListFragment extends Fragment {
    ListView listViewData;
    PlaceAdapter placeAdapter;
    List<PlaceModel> result = new ArrayList<PlaceModel>();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_list, container, false);
        Bundle args = getArguments();
        listViewData = (ListView) rootView.findViewById(android.R.id.list);
        // I will pass result and currentLocation here
        placeAdapter = new PlaceAdapter(getActivity(), R.layout.fragment_list_item, result, currentLocation);
        listViewData.setAdapter(placeAdapter);
        return rootView;
    }
}

AppSectionsPagerAdapter.java

public class AppSectionsPagerAdapter extends FragmentPagerAdapter {

final int PAGE_COUNT = 2;

public AppSectionsPagerAdapter(FragmentManager fm) {
    super(fm);
}

@Override
public Fragment getItem(int arg0) {
    Bundle data = new Bundle();
    switch(arg0) {
        case 0:
            PlaceListFragment fragment1 = new PlaceListFragment();
            fragment1.setArguments(data);
            return fragment1;
        default:
            PlaceListFragment fragment2 = new PlaceListFragment();
            fragment2.setArguments(data);
            return fragment2;
    }
}

@Override
public int getCount() {
    return PAGE_COUNT;
}
}

Answer 1

Find fragment in Activity onCreate and set data to a method you write in your fragment:

        ExampleFragment rf =  (ExampleFragment) getSupportFragmentManager().findFragmentById(R.id.exampleFragment);

    if(rf!=null){
    rf.setExample(currentExample);
    }

"CurrentExample" is whatever you want to send in to your "setExample" method in your fragment.

public void setExample(ExampleObject currentExample){

    currentExampleInFragment = currentExample;

}

You can use the data in onActivityCreated method of Fragment.

Not sure is this is a good solution or not, but I found it the easiest one for passing objects.

Answer 2

Usually the activities will have a reference to their fragments. In your SearchableActivity.java are you also loading PlaceListFragment.java either in setContentView(activity_searchable.xml); or you need to create a instance of the fragment and add/replace a fragment using FragmentTransaction.

you can find a good example here on how to communicated between fragments or between activity & fragment.

Training link