I solved this in an elegant way with RxAndroid. Receive an observer in the constructor of the DialogFragment and suscribe to observable and push the value when the callback being called. Then, in your Fragment create an inner class of the Observer, create an instance and pass it in the constructor of the DialogFragment. I used WeakReference in the observer to avoid memory leaks. Here is the code:
BaseDialogFragment.java
import java.lang.ref.WeakReference;
import io.reactivex.Observer;
public class BaseDialogFragment<O> extends DialogFragment {
protected WeakReference<Observer<O>> observerRef;
protected BaseDialogFragment(Observer<O> observer) {
this.observerRef = new WeakReference<>(observer);
}
protected Observer<O> getObserver() {
return observerRef.get();
}
}
DatePickerFragment.java
public class DatePickerFragment extends BaseDialogFragment<Integer>
implements DatePickerDialog.OnDateSetListener {
public DatePickerFragment(Observer<Integer> observer) {
super(observer);
}
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the current date as the default date in the picker
final Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int day = c.get(Calendar.DAY_OF_MONTH);
// Create a new instance of DatePickerDialog and return it
return new DatePickerDialog(getActivity(), this, year, month, day);
}
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
if (getObserver() != null) {
Observable.just(month).subscribe(getObserver());
}
}
}
MyFragment.java
//Show the dialog fragment when the button is clicked
@OnClick(R.id.btn_date)
void onDateClick() {
DialogFragment newFragment = new DatePickerFragment(new OnDateSelectedObserver());
newFragment.show(getFragmentManager(), "datePicker");
}
//Observer inner class
private class OnDateSelectedObserver implements Observer<Integer> {
@Override
public void onSubscribe(Disposable d) {
}
@Override
public void onNext(Integer integer) {
//Here you invoke the logic
}
@Override
public void onError(Throwable e) {
}
@Override
public void onComplete() {
}
}
You can see the source code here: https://github.com/andresuarezz26/carpoolingapp