Django Jinja2 Loader

django_jinja2_loader.py

import jinja2
from django.template.loader import BaseLoader
from django.template.loaders.app_directories import app_template_dirs
from django.template import TemplateDoesNotExist, Origin
from django.core import urlresolvers
from django.conf import settings

import datetime
import urllib
from django.utils.timesince import timesince, timeuntil

def yesno_filter(value, yes, no):
    return yes if value else no

def timesince_filter(value):
    return timsince(value, datatime.datetime.now())

def timeuntil_filter(value):
    return timeuntil(value, datetime.datetime.now())

class Template(jinja2.Template):
    def render(self, context):
        # flatten Django Context into a single dictionary
        context_dict = {}
        map(context_dict.update, context)
        if settings.TEMPLATE_DEBUG:
            # when testing views django.test.client
            # needs these extra signals sent to it
            from django.test import signals
            self.origin = Origin(self.filename)
            signals.template_rendered.send(
                sender=self, template=self, context=context)
        return super(Template, self).render(context_dict)

class Loader(BaseLoader):

    def __init__(self):
        super(Loader, self).__init__()
        self.is_usable = True
        self.env = jinja2.Environment(
            loader = jinja2.ChoiceLoader([jinja2.FileSystemLoader(path) \
                            for path in settings.JINJA2_TEMPLATE_DIRS]),
            # loader = jinja2.FileSystemLoader(app_template_dirs),
            trim_blocks = True,
            auto_reload = settings.DEBUG,
        )
        self.env.template_class = Template
        self.env.filters.update(dict(
            yesno     = yesno_filter,
            timesince = timesince_filter,
            timeuntil = timeuntil_filter,
            urlencode = urllib.urlencode,
        ))
        self.env.undefined = jinja2.StrictUndefined
        if settings.DEBUG or settings.TEMPLATE_DEBUG:
            self.env.undefined = jinja2.DebugUndefined

    def load_template(self, template_name, template_dirs=None):
        try:
            template = self.env.get_template(template_name)
        except jinja2.TemplateNotFound:
            raise TemplateDoesNotExist(template_name)
        return template, template.filename

    def load_template_source(self, template_name, template_dirs=None):
        try:
            source, filename, uptodate = \
                    self.env.loader.get_source(self.env, template_name)
        except jinja2.TemplateNotFound:
            raise TemplateDoesNotExist(template_name)
        return source, filename