satnogs-db/db/base/templatetags/tags.py

from django import template
from django.core.urlresolvers import reverse
from django.utils.html import format_html

register = template.Library()


@register.simple_tag
def active(request, urls):
    if request.path in (reverse(url) for url in urls.split()):
        return 'active'
    return None


@register.filter
def frq(value):
    try:
        to_format = float(value)
    except (TypeError, ValueError):
        return ''
    prec = int(to_format % 1000)
    formatted = format((to_format // 1000) / 1000, '.3f')
    if prec:
        stripped = str(prec).rstrip('0')
        formatted = format_html('{0}<small>{1}</small>', formatted, stripped)
    response = format_html('{0} MHz', formatted)
    return response