from django.contrib.syndication import feeds

from django.http import HttpResponse, Http404

def feed(request, url, feed_dict=None):

    if not feed_dict:

        raise Http404, "No feeds are registered."

    try:

        slug, param = url.split('/', 1)

    except ValueError:

        slug, param = url, ''

    try:

        f = feed_dict[slug]

    except KeyError:

        raise Http404, "Slug %r isn't registered." % slug

    try:

        feedgen = f(slug, request).get_feed(param)

    except feeds.FeedDoesNotExist:

        raise Http404, "Invalid feed parameters. Slug %r is valid, but other parameters, or lack thereof, are not." % slug

    response = HttpResponse(mimetype=feedgen.mime_type)

    feedgen.write(response, 'utf-8')

    return response