Switch language in jinja template

I'm migrating a multi lingual Django application from Django's template engine to Jinja2. In the templates I currently switch the active language on a per object basis using Django's language template tag i.e.:

{% load i18n %}
<h1>{% trans 'Page title' %}</h1>
<ul>
{% for obj in object_list %}
{% language obj.language_code %}
    <li><a href="{{ obj.get_absolute_url }}">{% trans 'view' %}: {{ obj.title }}</a>
{% endlanguage %}
{% endfor %}
</ul>

We also use i18n_patterns so the urls of each object are language specific as well.

I'm stuck on how to convert this to Jinja. I cannot use Django's i18n template tags and cannot find something equivalent for Jinja.

I was also looking at Babel to help with extracting messages from the templates. So a solution that works with Babel as well as with Django would be preferred.

It turns out it's fairly simple to do this by writing a custom jinja2 extension (I've based this on the example in the jinja2 docs):

from django.utils import translation
from jinja2.ext import Extension, nodes

class LanguageExtension(Extension):
    tags = {'language'}

    def parse(self, parser):
        lineno = next(parser.stream).lineno
        # Parse the language code argument
        args = [parser.parse_expression()]
        # Parse everything between the start and end tag:
        body = parser.parse_statements(['name:endlanguage'], drop_needle=True)
        # Call the _switch_language method with the given language code and body
        return nodes.CallBlock(self.call_method('_switch_language', args), [], [], body).set_lineno(lineno)

    def _switch_language(self, language_code, caller):
        with translation.override(language_code):
            # Temporarily override the active language and render the body
            output = caller()
        return output

# Add jinja2's i18n extension
env.add_extension('jinja2.ext.i18n')
# Install Django's translation module as the gettext provider
env.install_gettext_translations(translation, newstyle=True)
# Add the language extension to the jinja2 environment
environment.add_extension(LanguageExtension)

With this extension in place switching the active translation language is pretty much exactly like how you'd do it in Django:

{% language 'en' %}{{ _('Hello World'){% endlanguage %}

The only caveat is that when using Django as a gettext provider and Babel as a message extractor it's important to tell Babel to set the message domain to django when running init/update/compile_catalog.