onCreateView() isn't called immediately after FragmentTransaction.commit()

Question

I have an activity where I dynamically replace fragments:

private void goToFragment(Fragment newFragment, String tag) {
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    ft.replace(R.id.fragment_container, newFragment, tag);
    ft.addToBackStack(null);
    ft.commit();
}

Now, I want to access the views inside the fragment so I can put data (that I have stored in my activity) into them, immediately after calling goToFragment.

The problem is, the fragment's onCreateView isn't called before the fragment is rendered completely, at least to my understanding.

I know overriding the onAttach(Activity activity) in the fragment is one way to go about it, but then I have to cast it specifically to my activity - and I just want to avoid that because I consider it bad practice for the fragment to be dependent on a specific activity.

As far as I can see, Fragment doesn't have any listeners (as a subject) implemented.

So I figure I have to make my own listener (Using the Observer Pattern to make the fragment a subject and the activity an observer), and then calling it whenever the onCreateView or onAttach is done, and then finally calling back to the fragment with the data that needs to be set. However, I need to do this for several fragments so I would have to make a listener for each fragment, which I again think is bad.

Is there any better/easier way to do this?

Answer 1

FragmentTransaction isn't applied instantly after calling commit(). You may force update manually:

...
mFragmentManager.executePendingTransactions();

AFAIK event callbacks' purpose is custom communication with Fragment beyond it's usual lifecycle.

Answer 2

The correct way to do it would be to define an interface for Activity classes wishing to display your Fragment should implement. That way, on onAttach you don't cast to a specific Activity but to your interface.

See for instance: http://developer.android.com/guide/topics/fundamentals/fragments.html#EventCallbacks