'Override in a subclass to customize extraction of the :term:`URL` that points
to the content for each article. Return the
article URL. It is called with `article`, an object representing a parsed article
from a feed. See `feedparser <https://pythonhosted.org/feedparser/>`_.
By default it looks for the original link (for feeds syndicated via a
service like feedburner or pheedo) and if found,
returns that or else returns
`article.link <https://pythonhosted.org/feedparser/reference-entry-link.html>`_.'

def get_article_url(self, article):

    for key in article.keys():
        if key.endswith('_origlink'):
            url = article[key]
            if (url and (url.startswith('http://') or url.startswith('https://'))):
                return url
    ans = article.get('link', None)
    if ((not ans) and getattr(article, 'links', None)):
        for item in article.links:
            if (item.get('rel', 'alternate') == 'alternate'):
                ans = item['href']
                break
    return ans
