Which method is called when returning to a replaced fragment in a tablayout via calling popBackStackImmediate

Question

OK I found out that I am opening/replacing the fragment in another layout element than the one the tablayout is in. Therefore the underlying fragment is never really left if i understand correctly and also no lifecycle methods are triggered.

I have FragmentA inside a TabLayout from which i call:

//inside FragmentA
@Override
public void onClickView() {
    activity.replaceFragment(FragmentB.newInstance(), true);
}

in replaceFragment the passed fragment is added to the backstack in the transaction and then replaces the fragment

public void replaceFragment(Fragment fragment, boolean doAddToBackStack) {
    FragmentManager fm = getSupportFragmentManager();
    FragmentTransaction ft = fm.beginTransaction();

    if (doAddToBackStack) {
        String tag = fragment.getClass().toString();
        ft.addToBackStack(tag);
    }

    ft.replace(R.id.mainFragment, fragment);
    ft.commit();
}

After that, FragmentB opens, I do my stuff and return via popBackStackImmediate() to FragmentA:

//inside FragmentB
@Override
public void onClickBack() {
    activity.getSupportFragmentManager().popBackStackImmediate();
}

and when I go back I need to update something in FragmentA.

According to another post on the platform when returning to a fragment onCreateView() should be called but that does not work for me. According to the fragment lifecycle documentation the onCreateView() is only called the first time the UI is drawn which would explain my troubles.

My question is now what lifecycle method can I use or what other approach should I take to execute code when returning to a fragment from backstack?

@ianhanniballake I updated the post with the replaceFragment info — jteichert, Oct 07 '20 at 07:50

score 0 · Answer 1 · answered Oct 06 '20 at 20:39

According to the following answer you can add a listener to check when it is being called https://stackoverflow.com/a/52646588/6468214

getSupportFragmentManager().addOnBackStackChangedListener(
            new FragmentManager.OnBackStackChangedListener() {
                public void onBackStackChanged() {

                       // Your Code Here

                }
            });

Which method is called when returning to a replaced fragment in a tablayout via calling popBackStackImmediate

OK I found out that I am opening/replacing the fragment in another layout element than the one the tablayout is in. Therefore the underlying fragment is never really left if i understand correctly and also no lifecycle methods are triggered.

1 Answers1