Added jinja2 template backend.

django/template/backends/jinja2.py

+import sys
+
+from django.conf import settings
+from django.template import TemplateDoesNotExist
+from django.utils import six
+from django.utils.module_loading import import_string
+
+from jinja2 import (
+    DebugUndefined, FileSystemLoader, TemplateNotFound, Undefined)
+
+from .base import BaseEngine
+from .utils import csrf_input_lazy, csrf_token_lazy
+
+
+class Jinja2(BaseEngine):
+
+    app_dirname = 'jinja2'
+
+    def __init__(self, params):
+        params = params.copy()
+        options = params.pop('OPTIONS').copy()
+        super(Jinja2, self).__init__(params)
+
+        environment = options.pop('environment', 'jinja2.Environment')
+        environment_cls = import_string(environment)
+
+        options.setdefault('autoescape', True)
+        options.setdefault('loader', FileSystemLoader(self.template_dirs))
+        options.setdefault('auto_reload', settings.DEBUG)
+        options.setdefault('undefined',
+                           DebugUndefined if settings.DEBUG else Undefined)
+
+        self.env = environment_cls(**options)
+
+    def from_string(self, template_code):
+        return Template(self.env.from_string(template_code))
+
+    def get_template(self, template_name):
+        try:
+            return Template(self.env.get_template(template_name))
+        except TemplateNotFound as exc:
+            six.reraise(TemplateDoesNotExist, TemplateDoesNotExist(exc.args),
+                        sys.exc_info()[2])
+
+
+class Template(object):
+
+    def __init__(self, template):
+        self.template = template
+
+    def render(self, context=None, request=None):
+        if context is None:
+            context = {}
+        if request is not None:
+            context['request'] = request
+            context['csrf_input'] = csrf_input_lazy(request)
+            context['csrf_token'] = csrf_token_lazy(request)
+        return self.template.render(**context)