class BaseIndex(indexes.SearchIndex):
    model = None
text = indexes.CharField(document=True, use_template=True)
object_id = indexes.IntegerField()
timestamp = indexes.DateTimeField()

def get_model(self):
    return self.model


class PersonIndex(BaseIndex, indexes.Indexable):
    first_name = indexes.CharField()
middle_name = indexes.CharField()
last_name = indexes.CharField()

def get_model(self):
    return Person
How to make an abstract Haystack SearchIndex class