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165 lines
7.2 KiB
165 lines
7.2 KiB
"""HTML utilities suitable for global use.""" |
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import re |
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import string |
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from django.utils.safestring import SafeData, mark_safe |
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from django.utils.encoding import force_unicode |
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from django.utils.functional import allow_lazy |
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from django.utils.http import urlquote |
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# Configuration for urlize() function. |
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LEADING_PUNCTUATION = ['(', '<', '<'] |
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TRAILING_PUNCTUATION = ['.', ',', ')', '>', '\n', '>'] |
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# List of possible strings used for bullets in bulleted lists. |
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DOTS = ['·', '*', '\xe2\x80\xa2', '•', '•', '•'] |
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unencoded_ampersands_re = re.compile(r'&(?!(\w+|#\d+);)') |
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word_split_re = re.compile(r'(\s+)') |
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punctuation_re = re.compile('^(?P<lead>(?:%s)*)(?P<middle>.*?)(?P<trail>(?:%s)*)$' % \ |
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('|'.join([re.escape(x) for x in LEADING_PUNCTUATION]), |
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'|'.join([re.escape(x) for x in TRAILING_PUNCTUATION]))) |
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simple_email_re = re.compile(r'^\S+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+$') |
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link_target_attribute_re = re.compile(r'(<a [^>]*?)target=[^\s>]+') |
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html_gunk_re = re.compile(r'(?:<br clear="all">|<i><\/i>|<b><\/b>|<em><\/em>|<strong><\/strong>|<\/?smallcaps>|<\/?uppercase>)', re.IGNORECASE) |
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hard_coded_bullets_re = re.compile(r'((?:<p>(?:%s).*?[a-zA-Z].*?</p>\s*)+)' % '|'.join([re.escape(x) for x in DOTS]), re.DOTALL) |
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trailing_empty_content_re = re.compile(r'(?:<p>(?: |\s|<br \/>)*?</p>\s*)+\Z') |
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del x # Temporary variable |
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def escape(html): |
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"""Returns the given HTML with ampersands, quotes and carets encoded.""" |
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return mark_safe(force_unicode(html).replace('&', '&').replace('<', '<').replace('>', '>').replace('"', '"').replace("'", ''')) |
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escape = allow_lazy(escape, unicode) |
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def conditional_escape(html): |
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""" |
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Similar to escape(), except that it doesn't operate on pre-escaped strings. |
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""" |
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if isinstance(html, SafeData): |
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return html |
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else: |
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return escape(html) |
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def linebreaks(value, autoescape=False): |
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"""Converts newlines into <p> and <br />s.""" |
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value = re.sub(r'\r\n|\r|\n', '\n', force_unicode(value)) # normalize newlines |
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paras = re.split('\n{2,}', value) |
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if autoescape: |
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paras = [u'<p>%s</p>' % escape(p.strip()).replace('\n', '<br />') for p in paras] |
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else: |
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paras = [u'<p>%s</p>' % p.strip().replace('\n', '<br />') for p in paras] |
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return u'\n\n'.join(paras) |
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linebreaks = allow_lazy(linebreaks, unicode) |
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def strip_tags(value): |
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"""Returns the given HTML with all tags stripped.""" |
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return re.sub(r'<[^>]*?>', '', force_unicode(value)) |
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strip_tags = allow_lazy(strip_tags) |
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def strip_spaces_between_tags(value): |
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"""Returns the given HTML with spaces between tags removed.""" |
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return re.sub(r'>\s+<', '><', force_unicode(value)) |
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strip_spaces_between_tags = allow_lazy(strip_spaces_between_tags, unicode) |
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def strip_entities(value): |
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"""Returns the given HTML with all entities (&something;) stripped.""" |
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return re.sub(r'&(?:\w+|#\d+);', '', force_unicode(value)) |
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strip_entities = allow_lazy(strip_entities, unicode) |
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def fix_ampersands(value): |
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"""Returns the given HTML with all unencoded ampersands encoded correctly.""" |
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return unencoded_ampersands_re.sub('&', force_unicode(value)) |
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fix_ampersands = allow_lazy(fix_ampersands, unicode) |
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def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False): |
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""" |
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Converts any URLs in text into clickable links. |
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Works on http://, https://, www. links and links ending in .org, .net or |
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.com. Links can have trailing punctuation (periods, commas, close-parens) |
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and leading punctuation (opening parens) and it'll still do the right |
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thing. |
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If trim_url_limit is not None, the URLs in link text longer than this limit |
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will truncated to trim_url_limit-3 characters and appended with an elipsis. |
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If nofollow is True, the URLs in link text will get a rel="nofollow" |
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attribute. |
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If autoescape is True, the link text and URLs will get autoescaped. |
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""" |
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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 |
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safe_input = isinstance(text, SafeData) |
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words = word_split_re.split(force_unicode(text)) |
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nofollow_attr = nofollow and ' rel="nofollow"' or '' |
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for i, word in enumerate(words): |
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match = None |
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if '.' in word or '@' in word or ':' in word: |
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match = punctuation_re.match(word) |
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if match: |
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lead, middle, trail = match.groups() |
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# Make URL we want to point to. |
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url = None |
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if middle.startswith('http://') or middle.startswith('https://'): |
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url = urlquote(middle, safe='/&=:;#?+*') |
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elif middle.startswith('www.') or ('@' not in middle and \ |
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middle and middle[0] in string.ascii_letters + string.digits and \ |
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(middle.endswith('.org') or middle.endswith('.net') or middle.endswith('.com'))): |
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url = urlquote('http://%s' % middle, safe='/&=:;#?+*') |
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elif '@' in middle and not ':' in middle and simple_email_re.match(middle): |
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url = 'mailto:%s' % middle |
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nofollow_attr = '' |
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# Make link. |
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if url: |
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trimmed = trim_url(middle) |
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if autoescape and not safe_input: |
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lead, trail = escape(lead), escape(trail) |
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url, trimmed = escape(url), escape(trimmed) |
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middle = '<a href="%s"%s>%s</a>' % (url, nofollow_attr, trimmed) |
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words[i] = mark_safe('%s%s%s' % (lead, middle, trail)) |
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else: |
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if safe_input: |
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words[i] = mark_safe(word) |
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elif autoescape: |
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words[i] = escape(word) |
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elif safe_input: |
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words[i] = mark_safe(word) |
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elif autoescape: |
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words[i] = escape(word) |
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return u''.join(words) |
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urlize = allow_lazy(urlize, unicode) |
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def clean_html(text): |
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""" |
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Clean the given HTML. Specifically, do the following: |
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* Convert <b> and <i> to <strong> and <em>. |
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* Encode all ampersands correctly. |
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* Remove all "target" attributes from <a> tags. |
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* Remove extraneous HTML, such as presentational tags that open and |
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immediately close and <br clear="all">. |
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* Convert hard-coded bullets into HTML unordered lists. |
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* Remove stuff like "<p> </p>", but only if it's at the |
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bottom of the text. |
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""" |
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from django.utils.text import normalize_newlines |
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text = normalize_newlines(force_unicode(text)) |
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text = re.sub(r'<(/?)\s*b\s*>', '<\\1strong>', text) |
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text = re.sub(r'<(/?)\s*i\s*>', '<\\1em>', text) |
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text = fix_ampersands(text) |
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# Remove all target="" attributes from <a> tags. |
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text = link_target_attribute_re.sub('\\1', text) |
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# Trim stupid HTML such as <br clear="all">. |
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text = html_gunk_re.sub('', text) |
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# Convert hard-coded bullets into HTML unordered lists. |
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def replace_p_tags(match): |
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s = match.group().replace('</p>', '</li>') |
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for d in DOTS: |
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s = s.replace('<p>%s' % d, '<li>') |
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return u'<ul>\n%s\n</ul>' % s |
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text = hard_coded_bullets_re.sub(replace_p_tags, text) |
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# Remove stuff like "<p> </p>", but only if it's at the bottom |
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# of the text. |
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text = trailing_empty_content_re.sub('', text) |
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return text |
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clean_html = allow_lazy(clean_html, unicode)
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