How do I get python-markdown to additionally "urlify" links when formatting plain text?

Question

Markdown is a great tool for formatting plain text into pretty html, but it doesn't turn plain-text links into URLs automatically. Like this one:

http://www.google.com/

How do I get markdown to add tags to URLs when I format a block of text?

Answer 1

You could write an extension to markdown. Save this code as mdx_autolink.py

import markdown
from markdown.inlinepatterns import Pattern

EXTRA_AUTOLINK_RE = r'(?<!"|>)((https?://|www)[-\w./#?%=&]+)'

class AutoLinkPattern(Pattern):

    def handleMatch(self, m):
        el = markdown.etree.Element('a')
        if m.group(2).startswith('http'):
            href = m.group(2)
        else:
            href = 'http://%s' % m.group(2)
        el.set('href', href)
        el.text = m.group(2)
        return el

class AutoLinkExtension(markdown.Extension):
    """
    There's already an inline pattern called autolink which handles 
    <http://www.google.com> type links. So lets call this extra_autolink 
    """

    def extendMarkdown(self, md, md_globals):
        md.inlinePatterns.add('extra_autolink', 
            AutoLinkPattern(EXTRA_AUTOLINK_RE, self), '<automail')

def makeExtension(configs=[]):
    return AutoLinkExtension(configs=configs)

Then use it in your template like this:

{% load markdown %}

(( content|markdown:'autolink'))

Update:

I've found an issue with this solution: When markdown's standard link syntax is used and the displayed portion matches the regular expression, eg:

[www.google.com](http://www.yahoo.co.uk)

strangely becomes: www.google.com

But who'd want to do that anyway?!

Answer 2

Best case scenario, edit the markdown and just put < > around the URLs. This will make the link clickable. Only problem is it requires educating your users, or whoever writes the markdown.

Answer 3

There's an extra for this in python-markdown2:

http://code.google.com/p/python-markdown2/wiki/LinkPatterns

Answer 4

I couldn't get superjoe30's regular expression to compile, so I adapted his solution to convert plain URLs (within Markdown text) to be Markdown compatible.

The modified filter:

urlfinder = re.compile('^(http:\/\/\S+)')
urlfinder2 = re.compile('\s(http:\/\/\S+)')
@register.filter('urlify_markdown')
def urlify_markdown(value):
    value = urlfinder.sub(r'<\1>', value)
    return urlfinder2.sub(r' <\1>', value)

Within the template:

<div>
    {{ content|urlify_markdown|markdown}}
</div>