[flexcoders] SortField without a name doesn't refresh properly

[kyleashipley]

I would like to implement a sort on an ArrayCollection of composite
objects.  I tried using a SortField, but I have to leave the name
property blank because the data I want to sort on is one level deeper
(object.child.property instead of object.property) than normal.  When
I use a sort field in this manner, the refresh does not sort the
ArrayCollection as expected.

Here's a sample of what I'm talking about:

public function setupSort():Sort
{
        var sort:Sort = new Sort();
        var onlineSort:SortField = new SortField();
        onlineSort.compareFunction = compareFunc;
        sort.fields = [ onlineSort, new SortField("name", true) ];
        return sort;
}
                
private function compareFunc(a:Object, b:Object):void
{
        if ( a.buddyInfo.online && !b.buddyInfo.online ) return -1;
        if ( b.buddyInfo.online && !a.buddyInfo.online ) return 1;
        return 0;
}

(for reference, online is a Boolean)

If I call refresh on this list, I expect the online people to be
before the offline, but there is no rhyme or reason to the ordering.

Any suggestions?