Realm: Iterating a RealmObject and clearing an ArrayList field

Question

I have a RealmResults<Section> that has a RealmList<Event> field that I want to clear on each Section.

I've tried (insude mRealm.executeTransaction)

for (Section section : mSections) {
    section.getEvents().clear();
}

and

Iterator<Section> sectionIterator = mSections.iterator();
while (sectionIterator.hasNext()) {
    sectionIterator.next().getEvents().clear();
}

but Realm throws this exception

java.util.ConcurrentModificationException: No outside changes to a Realm is allowed while iterating a RealmResults. Use iterators methods instead.

Answer 1

Since you are not actually removing elements that you are iterating over, you can just use a traditional for loop:

for (int i = 0; i < mSections.size(); i++) {
    mSections.get(i).getEvents().clear();
}

Note that if you did need to remove elements using an Iterator, you would need to use the remove() method on the Iterator itself.

See Documentation