def _lazyload(self, element):
"""Inject attributes needed by lazysizes to lazy load elements.
For more information, see: https://afarkas.github.io/lazysizes
"""
assert element.tag in ('img', 'iframe', 'blockquote')
classes = element.attrib.get('class', '').split(' ')
if 'lazyload' in classes:
return # this should never happen
if element.tag == 'img':
src = self._lazyload_img(element)
elif element.tag == 'iframe':
src = self._lazyload_iframe(element)
elif element.tag == 'blockquote':
if 'twitter-tweet' not in classes:
return
src = self._lazyload_tweet(element)
classes.remove('twitter-tweet')
if src is None:
return # something went wrong
classes.append('lazyload')
element.attrib['class'] = ' '.join(classes).strip()
msg = '<{0}> tag with src="{1}" was processed for lazy loading'
logger.debug(msg.format(element.tag, src))
def _lazyload(self, element):
"""Inject attributes needed by lazysizes to lazy load elements.
For more information, see: https://afarkas.github.io/lazysizes
"""
assert element.tag in ('img', 'iframe', 'blockquote') # nosec
classes = element.attrib.get('class', '').split(' ')
if 'lazyload' in classes:
return # this should never happen
if element.tag == 'img':
src = self._lazyload_img(element)
elif element.tag == 'iframe':
src = self._lazyload_iframe(element)
elif element.tag == 'blockquote':
if 'twitter-tweet' not in classes:
return # not a tweet
src = self._lazyload_tweet(element)
if src is not None:
classes.remove('twitter-tweet')
if src is None:
return # something went wrong or lazy load not needed
classes.append('lazyload')
element.attrib['class'] = ' '.join(classes).strip()
msg = u'<{0}> tag with src="{1}" was processed for lazy loading'
logger.debug(msg.format(element.tag, src))
def _lazyload_tweet(element):
"""Process tweets for lazy loading. Twitter describes tweets
using <blockquote> tags with a `twitter-tweet` class and loads
a widget in a sibling <script> tag. To lazy load we need to add
a `data-twitter` attribute and remove the widget.
:param element: the HTML node to be processed
:type element: instance of lxml.html.HtmlElement
:returns: the URL of the tweet to be lazy loaded
:rtype: str
"""
assert element.tag == 'blockquote' # nosec
# processing a tweet is tricky and prone to errors
# abort at any time if the user has modified the code
element.attrib['data-twitter'] = 'twitter-tweet'
# remove sibling <script> tag to avoid an useless request
sibling = element.getnext()
if sibling is None:
return # Twitter's embed code was somehow modified, abort
widget = '//platform.twitter.com/widgets.js'
if sibling.tag == 'script' and widget in sibling.attrib['src']:
parent = element.getparent()
parent.remove(sibling)
logger.debug("Twitter's widget <script> tag removed")
try:
return element.find('a').attrib['href']
except AttributeError:
return # Twitter's embed code was somehow modified, abort
def _lazyload_tweet(self, element):
"""Process tweets for lazy loading. Twitter describes tweets
using <blockquote> tags with a `twitter-tweet` class and loads
a widget in a sibling <script> tag. To lazy load we need to add
a `data-twitter` attribute and remove the widget.
:param element: the HTML node to be processed
:type element: instance of lxml.html.HtmlElement
:returns: the URL of the tweet to be lazy loaded
:rtype: str
"""
assert element.tag == 'blockquote'
# processing a tweet is tricky and prone to errors
# abort at any time if the user has modified the code
element.attrib['data-twitter'] = 'twitter-tweet'
# remove sibling <script> tag to avoid an useless request
sibling = element.getnext()
if sibling is None:
return # Twitter's embed code was somehow modified, abort
widget = '//platform.twitter.com/widgets.js'
if sibling.tag == 'script' and widget in sibling.attrib['src']:
parent = element.getparent()
parent.remove(sibling)
logger.debug("Twitter's widget <script> tag removed")
try:
return element.find('a').attrib['href']
except AttributeError:
return # Twitter's embed code was somehow modified, abort
def _lazyload_tweet(self, element):
"""Process tweets for lazy loading. Twitter describes tweets
using <blockquote> tags with a `twitter-tweet` class and loads
a widget in a sibling <script> tag. To lazy load we need to add
a `data-twitter` attribute and remove the widget.
:param element: the HTML node to be processed
:type element: instance of lxml.html.HtmlElement
:returns: the URL of the tweet to be lazy loaded
:rtype: str
"""
assert element.tag == 'blockquote'
element.attrib['data-twitter'] = 'twitter-tweet'
# remove sibling <script> tag to avoid an useless request
widget = '//platform.twitter.com/widgets.js'
sibling = element.getnext()
if sibling.tag == 'script' and widget in sibling.attrib['src']:
parent = element.getparent()
parent.remove(sibling)
logger.debug("Twitter's widget <script> tag removed")
return element.find('a').attrib['href']
