Search all entries for given URL pattern(s) in a HTML page.

def fetchUrls(cls, url, data, urlSearch):
        """Search all entries for given URL pattern(s) in a HTML page."""
        searchUrls = []
        searches = makeSequence(urlSearch)
        for search in searches:
            for match in search.finditer(data[0]):
                searchUrl = match.group(1)
                if not searchUrl:
                    raise ValueError("Pattern %s matched empty URL at %s." % (search.pattern, url))
                out.debug(u'matched URL %r with pattern %s' % (searchUrl, search.pattern))
                searchUrls.append(normaliseURL(urljoin(data[1], searchUrl)))
            if searchUrls:
                # do not search other links if one pattern matched
                break
        if not searchUrls:
            patterns = [x.pattern for x in searches]
            raise ValueError("Patterns %s not found at URL %s." % (patterns, url))
        return searchUrls