Django and Jinja together at last

djangojinja.py

# -*- coding: utf-8 -*-
"""
    djangojinja2
    ~~~~~~~~~~~~

    Adds support for Jinja2 to Django.

    Configuration variables:

    ======================= =============================================
    Key                     Description
    ======================= =============================================
    `JINJA2_TEMPLATE_DIRS`  List of template folders
    `JINJA2_EXTENSIONS`     List of Jinja2 extensions to use
    `JINJA2_CACHE_SIZE`     The size of the Jinja2 template cache.
    `JINJA2_GLOBAL_FUNCS`   List of functions (as strings) to include.
    `JINJA2_GLOBAL_FILTERS` List of filters (as string) to include.
    ======================= =============================================

    :copyright: (c) 2009 by the Jinja Team.
    :license: BSD.
"""
from itertools import chain
from django.conf import settings
from django.http import HttpResponse
from django.template.loader import find_template_source
from django.template.context import get_standard_processors
from django.template import TemplateDoesNotExist
from django.utils.importlib import import_module
from jinja2 import Environment, FileSystemLoader, TemplateNotFound

# the environment is unconfigured until the first template is loaded.
_JINJA_ENV = None


def get_env():
    """Get the Jinja2 env and initialize it if necessary."""
    global _JINJA_ENV
    if _JINJA_ENV is None:
        _JINJA_ENV = create_env()
    return _JINJA_ENV


def import_attr(function):
    """Import a function/module attribute by string"""
    dot = function.rindex('.')
    att_module, att_name = function[:dot], function[dot+1:]
    return getattr(import_module(att_module), att_name)


def create_env():
    """Create a new Jinja2 environment."""
    searchpath = list(settings.JINJA2_TEMPLATE_DIRS)
    env = Environment(loader=FileSystemLoader(searchpath),
                      auto_reload=settings.TEMPLATE_DEBUG,
                      cache_size=getattr(settings, 'JINJA2_CACHE_SIZE', 50),
                      extensions=getattr(settings, 'JINJA2_EXTENSIONS', ()))
    # patch the environment to accept some global functions
    if hasattr(settings, 'JINJA2_GLOBAL_FUNCS'):
        env.globals['h'] = {}
        for function in list(settings.JINJA2_GLOBAL_FUNCS):
            function = import_attr(function)
            env.globals['h'][function.func_name] = function
    if hasattr(settings, 'JINJA2_GLOBAL_FILTERS'):
        for function in list(settings.JINJA2_GLOBAL_FILTERS):
            function = import_attr(function)
            env.filters[function.func_name] = function
    return env


def get_template(template_name, globals=None, request=None):
    """Load a template."""
    if request and 'jinja2.environment' in request.META:
        env = request.META['jinja2.environment']
    else:
        env = get_env()
    try:
        return env.get_template(template_name, globals=globals)
    except TemplateNotFound, ex:
        if settings.DEBUG:
            # find a template we know exists to avoid white screen of death
            find_template_source(template_name)
        raise TemplateDoesNotExist(str(ex))


def select_template(templates, globals=None, request=None):
    """Try to load one of the given templates."""
    if request and 'jinja2.environment' in request.META:
        env = request.META['jinja2.environment']
    else:
        env = get_env()
    for template in templates:
        try:
            return env.get_template(template, globals=globals)
        except TemplateNotFound:
            continue
    raise TemplateDoesNotExist(', '.join(templates))


def render_to_string(template_name, context=None, request=None,
                     processors=None):
    """Render a template into a string."""
    context = dict(context or {})
    if request is not None:
        with request.timed('context_processors'):
            context['request'] = request
            for processor in chain(get_standard_processors(), processors or ()):
                context.update(processor(request))
    template = get_template(template_name, request=request)
    return template.render(context)


def render_to_response(template_name, context=None, request=None,
                       processors=None, mimetype=None):
    """Render a template into a response object."""
    return HttpResponse(render_to_string(template_name, context, request,
                                         processors), mimetype=mimetype)

settings.py

# rest of settings here...

JINJA2_GLOBAL_FILTERS = [
    'django.template.defaultfilters.pluralize',
    'django.template.defaultfilters.date',
    'django.template.defaultfilters.urlencode',
    'django.template.defaultfilters.truncatewords_html',
    'django.contrib.humanize.templatetags.humanize.ordinal'
]

views.py

from djangojinja2 import render_to_response, render_to_string

# rest of stuff

def my_view(request):
    return render_to_response('my_view.jinja', {}, request)