Question

In a Django template, I need to transanlate some strings to a specific language (different from current one).

I would need something like this:

{% tans_to "de" "my string to translate" %}
or
{% blocktrans_to "de" %}my bloc to translate {% endblocktrans_to %}

to force translation to German.

I know I can call the following code in a view:

gettext.translation('django', 'locale', ['de'], fallback=True).ugettext("my string to translate")

Do I need to create a specific template tag ? Or does it already exist a dedicated tag in Django ?

Answer 1

templatetags/trans_to.py:

from django.utils import translation
from django.utils.translation import ugettext
from django.template import Library, Node,  Variable, TemplateSyntaxError
register = Library()

class TransNode(Node):
    def __init__(self, value, lc):
        self.value = Variable(value)
        self.lc = lc

    def render(self, context):        
        translation.activate(self.lc)
        val = ugettext(self.value.resolve(context))        
        translation.deactivate()        
        return val

def trans_to(parser, token):
    try:
        tag_name, value, lc = token.split_contents()
    except ValueError:
        raise TemplateSyntaxError, "%r tag requires arguments" % token.contents.split()[0]
    if not (lc[0] == lc[-1] and lc[0] in ('"', "'")):
        raise TemplateSyntaxError, "%r locale should be in quotes" % tag_name 
    return TransNode(value, lc[1:-1])

register.tag('trans_to', trans_to)

html:

{% load trans_to %}
{# pass string #}   
<p>{% trans_to "test" "de" %}</p>
<p>{% trans "test" %}</p>
{# pass variable #}
{% with "test" as a_variable %}
<p>{% trans_to a_variable "de" %}</p>
<p>{% trans a_variable %}</p>       
{% endwith %}

result:

<p>test in deutsch</p>
<p>test</p>
<p>test in deutsch</p>
<p>test</p>