Custom AsyncTaskLoader, loadinBackground not called after 5 attempts

Question

I have a SherlockListFragment that implements a custom AsyncTaskLoader. In the overridden onStartLoading(), I have:

@Override
protected void onStartLoading() {
  if (mData != null) {
    deliverResult(mData);
  }
  else{
    forceLoad();
  }
}

The containing SherlockListFragment initiates the loader in onActivityCreated:

@Override
public void onActivityCreated(Bundle savedInstanceState) {
  super.onActivityCreated(savedInstanceState);
  mAdapter = new MyListAdapter(getActivity());
  setListAdapter(mAdapter);
  getLoaderManager().initLoader(0, null, this);
}

and :

@Override
public Loader<List<MyData>> onCreateLoader(int id, Bundle args) {
  return new MyListLoader(getActivity());
}

The problem is that after 5 activations/navigations to my FragmentActivity, loadinBackground() is not called. The onStartLoding is called, as well as the forceLoad, but that's it. No Exception, nothing in the LogCat.

Any ideas?

Maurene

where/how do you trigger the loader in Activity ? – Costly

Did you ever solve this? Having a very similar issue. – Infusion

Was this ever resolved? I'm having the same issue in my project. – Kuykendall

To those who asked; no, I don't remember having this issue solved, sorry. In that project I ditched the Sherlock component(s) and moved on to the v7 app compat libraries. In that process, much was re-written and I haven't faced this issue again. – Maurene

Answer 1

It is Ok to call forceLoad().

See what documentation says:
You generally should only call this when the loader is started - that is, isStarted() returns true.

Full code:

@Override
protected void onStartLoading() {
    try {
        if (data != null) {
            deliverResult(data);
        }
        if (takeContentChanged() || data == null) {
            forceLoad();
        }

        Log.d(TAG, "onStartLoading() ");
    } catch (Exception e) {
        Log.d(TAG, e.getMessage());
    }
}

Important:

documentation says: Subclasses of Loader<D> generally must implement at least onStartLoading(), onStopLoading(), onForceLoad(), and onReset().

AsyncTaskLoader extends Loader but not implements onStartLoading(), onStopLoading(), onReset(). You must implement it by yourself!

---

P.S. I was confused with it after experience of using simple CursorLoader, I also thought that using forceLoad() is bad practice. But it is not true.

Stewardson

You saved my day! You're right, "onStartLoading()" has to be implemented even if it isn't required. Implementing it in my custom AsyncTaskLoader solved my problem. Thanks! – Illimani

Being AsycnTask deprecated, I tried AsyncTaskLoader and seems INCREDIBLE that you need to do this unclear tricks to make it work. Thanks. – Glochidium