def provider_from_url(self, url):
domain = get_domain(url)<EOL>site_tuples = self.get_cleaned_sites().values()<EOL>for domain_re, name, normalized_domain in site_tuples:<EOL><INDENT>if re.match(domain_re, domain):<EOL><INDENT>return normalized_domain, name<EOL><DEDENT><DEDENT>site = Site.objects.get_current()<EOL>return site.domain, site.name<EOL>
Given a URL for any of our sites, try and match it to one, returning
the domain & name of the match.  If no match is found, return current.

Returns a tuple of domain, site name -- used to determine 'provider'