AsyncTaskLoader doesn't run

Aitor Gómez picture Aitor Gómez · Dec 22, 2011 · Viewed 10.8k times · Source

I want to implement an AsyncTaskLoader in my project using the Compatibility Package, so I followed the Loader manual in Android Docs.

The problem is that the Loader does nothing, it seems loadInBackground() is never called

Any idea of what's wrong in my code? (ExpandableListFragment extends Fragment,but doesn't override any critical method )

Thank you :-)

/**EDIT:

I realized (late, I'm a moron) that AsyncTaskLoader is an abstract class so I need to subclass it... m(__)m I leave the question in case someone comes here behind me, who knows...

public class AgendaListFragment extends ExpandableListFragment implements
        LoaderManager.LoaderCallbacks<JSONArray> {

    private TreeMap<Integer, ArrayList<Evento>> mItems = new TreeMap<Integer, ArrayList<Evento>>();
    private AgendaListAdapter mAdapter;
    private ProgressBar mProgressBar;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View root = inflater.inflate(R.layout.fragment_agenda, container);
        mProgressBar = (ProgressBar) root.findViewById(R.id.loading);
        return root;

    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        mAdapter = new AgendaListAdapter(getActivity());
        setListAdapter(mAdapter);

        getLoaderManager().initLoader(0, null, this);

    }

    @Override
    public Loader<JSONArray> onCreateLoader(int arg0, Bundle arg1) {
        mProgressBar.setVisibility(View.VISIBLE);
        return new AsyncTaskLoader<JSONArray>(getActivity()) {
            @Override
            public JSONArray loadInBackground() {

                return getDataFromService(AgendaServices.LISTADO_MES);

            }

        };
    }

    @Override
    public void onLoadFinished(Loader<JSONArray> loader, JSONArray data) {

        // Some stuff to turn JSONArray into TreeMap

        mProgressBar.setVisibility(View.GONE);
        mAdapter.setItems(mItems);

    }

    @Override
    public void onLoaderReset(Loader<JSONArray> arg0) {
        mAdapter.setItems(null);
        mProgressBar.setVisibility(View.VISIBLE);

    }

}

Answer

David S. picture David S. · Jan 12, 2012

I think the best solution for the Compatibility package is to override the AsyncTaskLoader.onStartLoading method.

e.g.

@Override
protected void onStartLoading() {
  if(dataIsReady) {
    deliverResult(data);
  } else {
    forceLoad();
  }
}