Django messages framework with built-in Jinja2 backend

Question

How can I use the Django messages framework with Jinja2 and the built-in Jinja2 backend in Django 1.8?

I tried doing it as before, but then remembered that the Jinja2 backend doesn't have the context processors of Django Templating Language. Is it possible via the request as with session.

I have been using Django only for a few months, so even if the answer is obvious, please let me know.

I'm interested in this question as well, if I can't use the request.context object included in the Django Templates, this begs the question of why use Jinja2 at all? — Chris Hawkes, May 14 '15 at 17:35

score 12 · Answer 1 · answered Jun 17 '15 at 09:33

To expand a bit on the answer above, here's the step-by-step breakdown.

First, enable a custom Environment for jinja2, as described here

In settings.py, point the environment option for jinja2 to some function

`TEMPLATES = [
        {
            "BACKEND": "django_jinja.backend.Jinja2",
            "APP_DIRS": True,
            "OPTIONS": {
                "match_extension": ".jinja",
                "environment": "myapp.jinjaconfig.environment",
            }
        },
...]`

Now you write that function to add messages to the environment. Create myapp/jinjaconfig.py (or whatever name you choose, to match what you added to settings.py):

from jinja2 import Environment
from django.contrib import messages

def environment(**options):
    env = Environment(**options)
    env.globals.update({
        'get_messages': messages.get_messages,
        })
    return env

At this point you have get_messages available in your template. You can use it like this:

{% for message in get_messages(request) %}
<li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li>
{% endfor %}

Note that you have to pass in the request as an argument there

score 3 · Accepted Answer · answered May 19 '15 at 19:28

In the end I decided to go with the Jinja2 environment. I added a global callable to the environment like 'messages': messages.get_messages, which will let me access it like a context processor, but with messages(request) instead of the object 'messages' in DTL.

For beginners like me who doesn't know much about Jinja2, I added this callable to the jinja2.py file, which we create for enabling Jinja2 backend, just below the callable for url. You also have to import messages module from django.contrib in this file. Now, you can access the messages store from the Jinja2 template by accessing it using messages(request).

score 1 · Answer 3 · answered May 14 '15 at 18:32

1

There's a ticket 24694 about adding support for OPTIONS['context_processors'] to the Jinja2 template backend.

One of the suggestions from the discussion (it's quite long!) is to use django-jinja.

answered May 14 '15 at 18:32

Alasdair

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So, I am to assume that presently that is not possible with the built-in back end? Is there any workaround for now? – user2956979 May 14 '15 at 19:03
I think I will pass the message store from the view for now. django-jinja looks nice, but I guess I will stick with the built-in template support for now. (various reasons, one of which is a team scared of change) – user2956979 May 14 '15 at 19:27

mazurekt · Answer 4 · 2020-04-26T01:36:53.427

Use the django_jinja package.

In your settings.py file, you will be able to add a context_processor like the example below and it works without doing anything else:

# Just an example
TEMPLATES = [
    {
        "BACKEND": "django_jinja.backend.Jinja2",
        "APP_DIRS": True,
        "OPTIONS": {
            "context_processors": [
                "django.contrib.messages.context_processors.messages",
            ],
        }
    },

Doing this will merge the messages context into the template context.

Django messages framework with built-in Jinja2 backend

4 Answers4