utils.py

import os
import re


def apply_all_cleanings(content):
    return remove_br_in_ul(remove_br_in_pre(nl2br(fix_double_slash_escaping(content))))


def fix_double_slash_escaping(content):
    """
    Fix the double backslashes used to escape content and fix with proper replacement
    """
    return content.replace(u'\\r\\n', os.linesep)\
        .replace('\\"', '"')


def clean_pre(content):
    """
    Clean old <pre> tags with old classes and convert them to <pre><code>
    """
    result = re.sub(r'<pre class=\"lang.*?>', '<pre>', content)
    result = result.replace('<pre>', '<pre><code>')
    result = result.replace('</pre>', '</code></pre>')
    result = result.replace('<code><code>', '<code>')
    result = result.replace('</code></code>', '</code>')
    return result


def nl2br(content):
    """
    Replace \r\n (new line) with <br>
    """
    # split(escape(value)) causes html tags to be escaped: just split without escaping
    _paragraph_re = re.compile(r'(?:\r\n|\r(?!\n)|\n){2,}')
    result = u'\n\n'.join(u'<p>%s</p>' % p.replace('\n', '<br>\n')
                          for p in _paragraph_re.split(content))
    return result


def remove_br_in_pre(content):
    """
    Fix URLs in content, replace them with a new URL with different prefix

    >>> remove_br_in_pre('Check <pre> a b c <br> a b <br></pre> a b <br> c <pre>final<br></pre>')
    'Check <pre> a b c  a b </pre> a b <br> c <pre>final</pre>'
    """
    _re_content_in_pre = re.compile(r"<pre.*?>(.*?)</pre>", re.DOTALL)
    return re.sub(_re_content_in_pre, lambda match: match.group().replace('<br>', ''), content)


def remove_br_in_ul(content):
    """
    Get rid of <br> inside <ul> lists

    >>> remove_br_in_ul('<ul><li>abc<br></li></ul>')
    '<ul><li>abc</li></ul>'
    """
    _re_content_in_pre = re.compile(r"<ul>(.*?)</ul>", re.DOTALL)
    return re.sub(_re_content_in_pre, lambda match: match.group().replace('<br>', ''), content)