A custom RealTimeSearchIndex that also removes objects from the index when saved such that they should be.

indexes.py

from django.db.models import signals

from haystack import indexes


class RealTimeSearchIndex(indexes.RealTimeSearchIndex):
    """
    A variant of the stock ``RealTimeSearchIndex`` that constantly keeps the
    index fresh, including removing an object when it is saved to a state such
    that it should no longer be in the index. (The latter is not done by the
    stock one.)

    """

    def should_update(self, instance, **kwargs):
        """
        Determine if an object should be updated in the index.

        Different from the stock method in that this one does not always
        return true. Rather, we verify that we should actually update the
        object.

        """
        if instance in self.get_queryset():
            return True
        return False

    def update_object(self, instance, **kwargs):
        """
        Update the index for a single object. Attached to the class's
        post-save hook.

        """
        # Check to make sure we want to index this first.
        if self.should_update(instance, **kwargs):
            self.backend.update(self, [instance])
        else:
            # Otherwise, remove it.
            self.remove_object(instance)