def thumbnails(html):
"""
Given a HTML string, converts paths in img tags to thumbnail
paths, using Mezzanine's ``thumbnail`` template tag. Used as
one of the default values in the ``RICHTEXT_FILTERS`` setting.
"""
from django.conf import settings
from html5lib.treebuilders import getTreeBuilder
from html5lib.html5parser import HTMLParser
#from mezzanine.core.templatetags.mezzanine_tags import thumbnail
from asylum_custom.templatetags.asylum_tags import thumbnail
dom = HTMLParser(tree=getTreeBuilder("dom")).parse(html)
for img in dom.getElementsByTagName("img"):
src = img.getAttribute("src")
width = img.getAttribute("width")
height = img.getAttribute("height")
if src and width and height:
src = settings.MEDIA_URL + thumbnail(src, width, height)
img.setAttribute("src", src)
nodes = dom.getElementsByTagName("body")[0].childNodes
return "".join([node.toxml() for node in nodes])
