Extended QuerySelectField to allow SQLAlchemy objects to be passed in as default avalues

forms.py

class QuerySelectFieldCustom(QuerySelectField):
    """Extended to allow default checked items

    Probably a much more obvious way to do this...

    """
    selected = None

    def iter_choices(self):
        if self.allow_blank:
            yield (u'__None', self.blank_text, self.data is None)

        for pk, obj in self._get_object_list():
            if self.selected is not None and self.selected.id == obj.id:
                yield (pk, self.get_label(obj), True)
            else:
                yield (pk, self.get_label(obj), obj in self.data)