clevercss_helper.py

from django.conf import settings
from django.http import HttpResponse, HttpResponseNotFound
import os
import re
import clevercss

def serve_css(request, path):
	css_fname = os.path.join(settings.MEDIA_ROOT, path)
	ccss_fname = os.path.join(settings.MEDIA_ROOT, re.compile('\.css$').sub('.ccss', path))
	css = ccss = None
	if os.path.exists(css_fname):
		css_file = open(css_fname, 'rb')
		css = css_file.read()
		css_file.close()
	if os.path.exists(ccss_fname):
		ccss_file = open(ccss_fname, 'rb')
		ccss = ccss_file.read().decode('utf-8')
		ccss_file.close()
	response = HttpResponse(mimetype='text/css')
	if not ccss:
		if css:
			response.write(css)
			return response
		return HttpResponseNotFound()
	if css and os.stat(css_fname)[8] > os.stat(ccss_fname)[8]:
		response.write(css)
		return response
	css_file = open(css_fname, 'wb')
	css = clevercss.convert(ccss)
	css_file.write(css.encode('utf-8'))
	css_file.close()
	response.write(css)
	return response

urls.py

if settings.DEBUG:
	urlpatterns += patterns('',
			(r'media/(?P<path>.*\.css)$', 'clevercss_helper.serve_css'),
			(r'media/(?P<path>.*)$', 'django.views.static.serve', {'document_root': settings.MEDIA_ROOT}),
			)