An Example ModelResource using If-Modified Headers

if_modified.py

from time import mktime

from django.utils.http import http_date, parse_http_date_safe

from tastypie.exceptions import ImmediateHttpResponse
from tastypie.http import HttpNotModified

class IfModifiedResource(ModelResource):
    def cached_obj_get(self, request=None, **kwargs):
        bundle = super(IfModifiedResource, self).cached_obj_get(request, **kwargs)
        if not request:
            return bundle
        
        if_modified = request.META.get('HTTP_IF_MODIFIED_SINCE')
        if not if_modified:
            return bundle

        if_modified = parse_http_date_safe(if_modified)

        # Check if object changed since the time requested
        if bundle.obj.updated <= if_modified:
            response = http.HttpNotModified()
            response['Date'] = http_date()
            raise ImmediateHttpResponse(response=response)
            
        request._should_add_last_modified = True

        return bundle


    # We don't actually have a good place to check this, so this is a bit nasty
    def create_response(self, request, data, response_class=HttpResponse, **response_kwargs):
        response = super(IfModifiedResource, self).create_response(request, data, response_class, **response_kwargs)
        if getattr(request, '_should_add_last_modified', False):
            #Assuming data['updated'] is a datetime
            last_modified = time.mktime(data['updated'].timetuple())
            response['Last-Modified'] = http_date(last_modified)
        return response