Template translation helpers.

translation.py

from django import template
from django.conf import settings

if settings.USE_I18N:
    from django.utils.translation.trans_real import translation
    def get_translation(msgid, lang):
        t = translation(lang)
        return t.gettext(msgid)
else:
    def get_translation(msgid, lang):
        return msgid

register = template.Library()

class TranslateNode(template.Node):
    """
    Return a message in a given language.

    """
    def __init__(self, msgid, lang):
        self.msgid = msgid
        self.lang = lang

    def render(self, context):
        msgid = self.msgid.resolve(context)
        lang = self.lang.resolve(context)
        return get_translation(msgid, lang)

def do_translate(parser, token):
    try:
        tag, msgid, lang = token.split_contents()
    except ValueError:
        raise template.TemplateSyntaxError('translate takes two arguments: msgid and lang')
    msgid = parser.compile_filter(msgid)
    lang = parser.compile_filter(lang)
    return TranslateNode(msgid, lang)

register.tag('get_translation', do_translate)