Django Email Munger

This is the first custom template filter I have made for Django. It is used to hide email address’s on web sites from harvester type bots and so avoiding spam. This means you are free to display an email address on a web site as a mailto link without it displaying as plain text in the source code.

Just take the code from below, I hope the doc string explains it’s use but feel free to leave a comment or drop me an email if you have a question.

from django import template
from django.template.defaultfilters import stringfilter
from django.utils.safestring import mark_safe
from django.utils.html import conditional_escape
import re

register = template.Library()

@register.filter
@stringfilter
def mungify(email, text=None, autoescape=None):
    '''
    Template filter to hide an email address away from any sort of email harvester
    type web scrapers and so keep away from spam etc.

    The filter should be applied on a string which represents an email address. You
    can optionally give the filter a parameter which will represent the name of the
    resulting email href link. If no extra parameter is given the email address will
    be used as the href text.

    {{ email|mungify:"contact me" }}
    or
    {{ email|mungify }}

    The output is javascript which will write out the email href link in a way so
    as to not actually show the email address in the source code as plain text.
    '''
    text = text or email

    if autoescape:
        email = conditional_escape(email)
        text = conditional_escape(text)

    emailArrayContent = ''
    textArrayContent = ''
    r = lambda c: '"' + str(ord(c)) + '",'

    for c in email: emailArrayContent += r(c)
    for c in text: textArrayContent += r(c)

    result = """<script>
        var _tyjsdf = [%s], _qplmks = [%s];
        document.write('<a href="mailto:');
        for(_i=0;_i<_tyjsdf.length;_i++){document.write('&#'+_tyjsdf[_i]+';');}
        document.write('">');
        for(_i=0;_i<_qplmks.length;_i++){document.write('&#'+_qplmks[_i]+';');}
        document.write('</a>');
        </script>""" % (re.sub(r',$', '', emailArrayContent), re.sub(r',$', '', textArrayContent))

    return mark_safe(result)

mungify.needs_autoescape = True

I’ve also posted this on djangosnippets.org.