Create BaseFragment and extend this Fragment in ChildFragment

Question

I don't know whether this is repeated question or not, But I didn't found any solution.

The problem is, there is a screen which has similar views in all the screens, that screens are in fragment.

So, I want to create a base fragment and want to extend this base fragment in all child fragments.

I found on google, for demo examples, But I didn't find any solution.

I don't know from where to start.

Please help me.

I found this links but it is not much clear:

1. Fragments inheritance Android

2. When do I need a base activity and base fragment?

BaseFragment.java

public class BaseFragment extends Fragment {

  public BaseFragment() {
    // Required empty public constructor
  }

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

    return inflater.inflate(R.layout.fragment_base, container, false);
  }
}

ChildFragment.Java

public class ChildFragment extends BaseFragment{

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_child, container, false);
  }
}

Now, there is a TextView in fragment_child layout. that is displayed when I run the app, but there are two other views in fragment_base, that is not showing...

Answer 1

ABSTRACT CLASS APPROACH ?

I understand what you are trying to do (inheritance) here. But as pointed out by @hobokent, just by inheriting the BaseClass will not include your childView layout on top of BaseClass Layout. There are many ways to conquer this problem

Let's look into this solution.

• Create an abstract class which will extend the Fragment Class (This will be BaseClass).

• Make an abstract method which will return a layout.

• Provide implementation for your abstract method in the ChildClass.

Here is the code snippet.

BaseClass

public abstract class BasicFragment extends Fragment {

  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
  }

  public View onCreateView(LayoutInflater inflater,ViewGroup parent, Bundle savedInstanseState)
   {
      View view = provideYourFragmentView(inflater,parent,savedInstanseState);
      return view;
   }

   public abstract View provideYourFragmentView(LayoutInflater inflater,ViewGroup parent, Bundle savedInstanceState);

}

ChildClass

public class ImageFragment extends BasicFragment{

  @Override
  public View provideYourFragmentView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.image_fragment,parent,false);

    //Now specific components here (you can initialize Buttons etc)

    return view;
   }


}

For your specific requirement, if you want the same layout to appear in child class layout. You can make a method which will return a layout and maybe in your child layout you make a placeholder for BaseClass Layout and add the BaseClass layout in childLayout using child.add(base_layout). Again it is just another design solution.
You can also put a common layout in Activity layout and Add fragment in Activity placeholder for the fragment. There are so many possible solutions.

I don't have any code specific to your requirement but here is the example where I have implemented this approach for TabLayout, where each tab is a different Fragment with a different layout.
Github full code sample.