"""HTML utilities suitable for global use.""" import re import string from django.utils.safestring import SafeData, mark_safe from django.utils.encoding import force_unicode from django.utils.functional import allow_lazy from django.utils.http import urlquote # Configuration for urlize() function. LEADING_PUNCTUATION = ['(', '<', '<'] TRAILING_PUNCTUATION = ['.', ',', ')', '>', '\n', '>'] # List of possible strings used for bullets in bulleted lists. DOTS = ['·', '*', '\xe2\x80\xa2', '•', '•', '•'] unencoded_ampersands_re = re.compile(r'&(?!(\w+|#\d+);)') word_split_re = re.compile(r'(\s+)') punctuation_re = re.compile('^(?P(?:%s)*)(?P.*?)(?P(?:%s)*)$' % \ ('|'.join([re.escape(x) for x in LEADING_PUNCTUATION]), '|'.join([re.escape(x) for x in TRAILING_PUNCTUATION]))) simple_email_re = re.compile(r'^\S+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+$') link_target_attribute_re = re.compile(r'(]*?)target=[^\s>]+') html_gunk_re = re.compile(r'(?:
|<\/i>|<\/b>|<\/em>|<\/strong>|<\/?smallcaps>|<\/?uppercase>)', re.IGNORECASE) hard_coded_bullets_re = re.compile(r'((?:

(?:%s).*?[a-zA-Z].*?

\s*)+)' % '|'.join([re.escape(x) for x in DOTS]), re.DOTALL) trailing_empty_content_re = re.compile(r'(?:

(?: |\s|
)*?

\s*)+\Z') del x # Temporary variable def escape(html): """Returns the given HTML with ampersands, quotes and carets encoded.""" return mark_safe(force_unicode(html).replace('&', '&').replace('<', '<').replace('>', '>').replace('"', '"').replace("'", ''')) escape = allow_lazy(escape, unicode) def conditional_escape(html): """ Similar to escape(), except that it doesn't operate on pre-escaped strings. """ if isinstance(html, SafeData): return html else: return escape(html) def linebreaks(value, autoescape=False): """Converts newlines into

and
s.""" value = re.sub(r'\r\n|\r|\n', '\n', force_unicode(value)) # normalize newlines paras = re.split('\n{2,}', value) if autoescape: paras = [u'

%s

' % escape(p.strip()).replace('\n', '
') for p in paras] else: paras = [u'

%s

' % p.strip().replace('\n', '
') for p in paras] return u'\n\n'.join(paras) linebreaks = allow_lazy(linebreaks, unicode) def strip_tags(value): """Returns the given HTML with all tags stripped.""" return re.sub(r'<[^>]*?>', '', force_unicode(value)) strip_tags = allow_lazy(strip_tags) def strip_spaces_between_tags(value): """Returns the given HTML with spaces between tags removed.""" return re.sub(r'>\s+<', '><', force_unicode(value)) strip_spaces_between_tags = allow_lazy(strip_spaces_between_tags, unicode) def strip_entities(value): """Returns the given HTML with all entities (&something;) stripped.""" return re.sub(r'&(?:\w+|#\d+);', '', force_unicode(value)) strip_entities = allow_lazy(strip_entities, unicode) def fix_ampersands(value): """Returns the given HTML with all unencoded ampersands encoded correctly.""" return unencoded_ampersands_re.sub('&', force_unicode(value)) fix_ampersands = allow_lazy(fix_ampersands, unicode) def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False): """ Converts any URLs in text into clickable links. Works on http://, https://, www. links and links ending in .org, .net or .com. Links can have trailing punctuation (periods, commas, close-parens) and leading punctuation (opening parens) and it'll still do the right thing. If trim_url_limit is not None, the URLs in link text longer than this limit will truncated to trim_url_limit-3 characters and appended with an elipsis. If nofollow is True, the URLs in link text will get a rel="nofollow" attribute. If autoescape is True, the link text and URLs will get autoescaped. """ trim_url = lambda x, limit=trim_url_limit: limit is not None and (len(x) > limit and ('%s...' % x[:max(0, limit - 3)])) or x safe_input = isinstance(text, SafeData) words = word_split_re.split(force_unicode(text)) nofollow_attr = nofollow and ' rel="nofollow"' or '' for i, word in enumerate(words): match = None if '.' in word or '@' in word or ':' in word: match = punctuation_re.match(word) if match: lead, middle, trail = match.groups() # Make URL we want to point to. url = None if middle.startswith('http://') or middle.startswith('https://'): url = urlquote(middle, safe='/&=:;#?+*') elif middle.startswith('www.') or ('@' not in middle and \ middle and middle[0] in string.ascii_letters + string.digits and \ (middle.endswith('.org') or middle.endswith('.net') or middle.endswith('.com'))): url = urlquote('http://%s' % middle, safe='/&=:;#?+*') elif '@' in middle and not ':' in middle and simple_email_re.match(middle): url = 'mailto:%s' % middle nofollow_attr = '' # Make link. if url: trimmed = trim_url(middle) if autoescape and not safe_input: lead, trail = escape(lead), escape(trail) url, trimmed = escape(url), escape(trimmed) middle = '
%s' % (url, nofollow_attr, trimmed) words[i] = mark_safe('%s%s%s' % (lead, middle, trail)) else: if safe_input: words[i] = mark_safe(word) elif autoescape: words[i] = escape(word) elif safe_input: words[i] = mark_safe(word) elif autoescape: words[i] = escape(word) return u''.join(words) urlize = allow_lazy(urlize, unicode) def clean_html(text): """ Clean the given HTML. Specifically, do the following: * Convert and to and . * Encode all ampersands correctly. * Remove all "target" attributes from tags. * Remove extraneous HTML, such as presentational tags that open and immediately close and
. * Convert hard-coded bullets into HTML unordered lists. * Remove stuff like "

  

", but only if it's at the bottom of the text. """ from django.utils.text import normalize_newlines text = normalize_newlines(force_unicode(text)) text = re.sub(r'<(/?)\s*b\s*>', '<\\1strong>', text) text = re.sub(r'<(/?)\s*i\s*>', '<\\1em>', text) text = fix_ampersands(text) # Remove all target="" attributes from
tags. text = link_target_attribute_re.sub('\\1', text) # Trim stupid HTML such as
. text = html_gunk_re.sub('', text) # Convert hard-coded bullets into HTML unordered lists. def replace_p_tags(match): s = match.group().replace('

', '') for d in DOTS: s = s.replace('

%s' % d, '

  • ') return u'
      \n%s\n
    ' % s text = hard_coded_bullets_re.sub(replace_p_tags, text) # Remove stuff like "

      

    ", but only if it's at the bottom # of the text. text = trailing_empty_content_re.sub('', text) return text clean_html = allow_lazy(clean_html, unicode)