Passing data from Activity to Fragments

Question

I have finished a simple app to list all products from a mysql database via json. When I click a specific product, it takes me to an activity that displays it's details. Now I changed my app so that when I click a specific product from the list it goes to a 3 tabbed fragment. I have created all the relevant fragments and everything works fine. It only doesn't work when I try to pass the data from the list all products activity to the details fragment activity. How can I pass the data from the main screen which lists all products to the 3 fragments that display the details?

further explanation:

working example without the framents: Main activity displays all products and passes it to details activity upon selecting a single product-> details activity gets data from main activity and displays details

Now I have the main activity which displays all products. Do I pass the data to -> "public class EmpresaDetailsActivity extends FragmentActivity implements ActionBar.TabListener { etc" or do I have to pass it to all other 3 single fragments that I created?

(old way)List all products:

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.all_empresas);

        empresaList = new ArrayList<HashMap<String, String>>();

        // Get listview
        ListView lv = getListView();

        // on selecting single empresa
        // launching Empresa Details Screen
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                // getting values from selected ListItem
                String eid = ((TextView) view.findViewById(R.id.eid)).getText().toString();
                String marca = ((TextView) view.findViewById(R.id.marca)).getText().toString();
                String investimento = ((TextView) view.findViewById(R.id.investimento)).getText().toString();
                String marcatotal = ((TextView) view.findViewById(R.id.marcatotal)).getText().toString();

                // Starting new intent
                Intent in = new Intent(getApplicationContext(),EmpresaDetailsActivity.class);
                // sending data to next activity
                in.putExtra(TAG_EID, eid);
                in.putExtra(TAG_MARCA, marca);
                in.putExtra(TAG_INVESTIMENTO, investimento);
                in.putExtra(TAG_MARCATOTAL, marcatotal);

                // starting new activity and expecting some response back
                startActivity(in);
            }
        });

        // Loading empresa in Background Thread
        new LoadAllEmpresa().execute();
    }

(old way)Details of a single product:

public class EmpresaDetailsActivity  extends Activity {

    // JSON node keys
    private static final String TAG_EID = "eid";
    private static final String TAG_MARCA = "marca";
    private static final String TAG_INVESTIMENTO = "investimento";
    private static final String TAG_MARCATOTAL = "marcatotal";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.details_empresa);

        // getting intent data
        Intent in = getIntent();

        // Get JSON values from previous intent
        String eid = in.getStringExtra(TAG_EID);
        String marca = in.getStringExtra(TAG_MARCA);
        String investimento = in.getStringExtra(TAG_INVESTIMENTO);
        String marcatotal = in.getStringExtra(TAG_MARCATOTAL);

        // Displaying all values on the screen
        TextView lblEid = (TextView) findViewById(R.id.showEid);
        TextView lblName = (TextView) findViewById(R.id.showMarca);
        TextView lblInvestimento = (TextView) findViewById(R.id.showInvestimento);
        TextView lblMarcatotal = (TextView) findViewById(R.id.showMarcaTotal);

        lblEid.setText(eid);
        lblName.setText(marca);
        lblInvestimento.setText(investimento);
        lblMarcatotal.setText(marcatotal);
    }
}

New Details class that has the 3 fragments:

public class EmpresaDetailsActivity extends FragmentActivity implements ActionBar.TabListener {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private ActionBar actionBar;
    // Tab titles
    private String[] tabs = { "Apresentação", "Ficha Técnica", "Pedir Informação" };

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

        // Initilization
        viewPager = (ViewPager) findViewById(R.id.pager);
        actionBar = getActionBar();
        mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

        viewPager.setAdapter(mAdapter);
        actionBar.setHomeButtonEnabled(false);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Adding Tabs
        for (String tab_name : tabs) {
            actionBar.addTab(actionBar.newTab().setText(tab_name)
                    .setTabListener(this));
        }

        /**
         * on swiping the viewpager make respective tab selected
         * */
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                // on changing the page
                // make respected tab selected
                actionBar.setSelectedNavigationItem(position);
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
            }
        });
    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        // on tab selected
        // show respected fragment view
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    }

}

TabsPagerAdapter class:

public class TabsPagerAdapter extends FragmentPagerAdapter {

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

    @Override
    public Fragment getItem(int index) {

        switch (index) {
        case 0:
            // Top Rated fragment activity
            return new ApresentacaoFragment();
        case 1:
            // Games fragment activity
            return new FichaTecnicaFragment();
        case 2:
            // Movies fragment activity
            return new PedirInformacaoFragment();
        }

        return null;
    }

    @Override
    public int getCount() {
        // get item count - equal to number of tabs
        return 3;
    }

}

example of 1 of the 3 fragments:

public class ApresentacaoFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_apresentacao, container, false);

        return rootView;
    }
}

Answer 1

On your activity onItemClick(), before launching the fragment:

Bundle args = new Bundle();
args.putString(TAG_EID, eid);
args.putString(TAG_MARCA, marca);
args.putString(TAG_INVESTIMENTO, invetstimento);
args.putString(TAG_MARCATOTLA, marcatotal);
yourFragment.setArguments(args);

On your fragment OnCreateView():

Bundle args = getArguments();
String marca = args.getString(TAG_MARCA);
// and so on...

And to be more clear, here is how you should pass data between Activities/Fragments.

• Activity --> Fragment : Use Bundle and setArguments. (As shown above)
• Activity --> Activity : Use Intent and putExtra.
• Fragment --> Activity : Use Interface. Avtivity should implement it, Fragment should call it.

---

After checking your new code:

1. Wrap your Strings inside a Bundle and pass it from MainActivity to your EmpresaDetailsActivity.
2. Fetch it there using getIntent().getExtras().

3. Change your TabsPagerAdapter to:

   public class TabsPagerAdapter extends FragmentPagerAdapter {
   
   private Bundle args;
   
   public TabsPagerAdapter(FragmentManager fm, Bundle args) {
       super(fm);
       this.args = args;
   }
   
   @Override
   public Fragment getItem(int index) {
   
   switch (index) {
   case 0:
       // Top Rated fragment activity
       ApresentacaoFragment apresentacaoFragment = new ApresentacaoFragment();
       apresentacaoFragment.setArguments(args);
       return apresentacaoFragment;
   case 1:
       // Games fragment activity
       // do the same as above with your Games fragmnet class
   case 2:
       // Movies fragment activity
       // ...
   }
   
   return null;
    }
   
    @Override
   public int getCount() {
       // get item count - equal to number of tabs
       return 3;
   }   
   }
   

   4. When instantiate the adapter, pass the bundle to its constructor.
   5. In your fragment classes use getArguments() to fetch the bundle and you're done.

Answer 2

Since EmpresaDetailsActivity is the Activity that is containing your three Fragments I think is a good practice to pass the data from MainActivity to EmpresaDetailsActivity and then from there pass it to the Fragments. That way you are respecting hierarchy.

To pass values to a Fragment from an Activity you can do as follows:

1) In each Fragment class define a static method called newInstance, where you will get all the values

public static YourFragmentClass newInstance(int myValue, int MyValue2) {
    // You can add as many values as you need to initialize your fragment
    YourFragmentClass fragment = new YourFragmentClass();
    Bundle args = new Bundle();
    args.putInt("value_key", myValue);
    args.putInt("value_key2", myValue2);
    fragment.setArguments(args);
    return fragment;
}

2) In your TabAdapter when your create the Fragments, just replace your Fragment declaration with

YourFragmentClass.newInstance(value1, value2);

3) On the onCreate method of each Fragment retrieve the values that you passed:

@Override
public View onCreate(Bundle savedInstanceState) {

    int myValue = getArguments().getInt("value_key"));
    int myValue2 = getArguments().getInt("value_key2"));
}

That way you have a cleaner way to initialize your Fragments