from haystack.sites import site
from django.db.models import signals

def add_to_search_index(sender, instance=None, **kwargs):
    try:
        index = site.get_index(instance.__class__)
    except:
        return
    
    index.backend.update(index, [instance])
signals.post_save.connect(add_to_search_index)

def delete_from_search_index(sender, instance=None, **kwargs):
    try:
        index = site.get_index(instance.__class__)
    except:
        return
    
    index.backend.remove(instance)
signals.post_delete.connect(delete_from_search_index)