athe.la blog

I wrote my own wordbreak filter for django

I realised quickly that when I wrote a long unbroken piece of text in one of my chirps, the div would expand (not good).  I did experiment with the overflow:auto CSS property to make the div scrollable horizontally when required but wanted a different method.  Facebook uses a <wbr> tag in long words to break them up but in my research I found that &shy; was the most commonly supported amongst most browsers.

The filter works at the template level and uses a single int to determine the number of spaces to insert the break lines.  Here’s an example: {{ object.content|wordbreak:”10″ }}

At every nth character of a word that is more than n characters long, a string of the datetime now plus a custom string plus the datetime again is placed.  The string is then conditionally escaped to make the string safe to render and then the custom string is replaced with &shy;.

from django.utils.html import conditional_escape
from django.utils.safestring import mark_safe
from datetime import datetime
import re

from django import template
register = template.Library()

@register.filter
def wordbreak (string, arg):
    search = '([^ ]{' + arg + '})'
    t = datetime.now()
    wbr = t.strftime("%A%d%B%Y%f") + 'wbr_here' + t.strftime("%A%d%B%Y%f")
    saferesult = conditional_escape(re.sub( search, '\\1' + wbr, string ))
    result = saferesult.replace(wbr,'­')
    return mark_safe(result)

source code also available at http://www.djangosnippets.org/snippets/1432/