Skeleton for adding a QR code at the end of articles

qr_code_skeleton.recipe

from calibre.web.feeds.news import BasicNewsRecipe
from calibre.ebooks.BeautifulSoup import BeautifulSoup, Tag
import urllib

class QrCodeSkeletonRecipe(BasicNewsRecipe):
    # If True, it will add a QR code with the article's URL at the
    # end of each article.
    qr_code = True

    # If keep_only tags is used, don't forget to add the qr-code to it.
    # keep_only_tags = [
    #     dict(name='p', attrs={'class':'qr-code'}),
    # ]

    # Add a QR-code for sharing
    @staticmethod
    def get_qr_code_img(data, size='450x450'):
        # The URL of the http://goqr.me/ service
        qr_api_url = 'https://api.qrserver.com/v1/create-qr-code/?'
        qr_img = Tag(BeautifulSoup(), 'img')
        parameters = urllib.urlencode({'data': data, 'size': size})
        qr_img['src'] = qr_api_url + parameters
        # We set the width to enable zooming-in on Kindle devices
        qr_img['style'] = 'width: 3cm; height: 3cm;'
        return qr_img

    def preprocess_raw_html(self, raw_html, url):
        if self.qr_code:
            qr_img = self.get_qr_code_img(url)
            soup = BeautifulSoup(raw_html)
            soup.body.append('<p class="qr-code" style="text-align:center;">Share article<br/>%s</p>' % qr_img)
            raw_html = soup.prettify()
        return raw_html