UndefinedError: 'url_for' is undefined; while using Jinja2 in Django

Question

I'm trying to use Jinja2 templating language with Django. While trying to render a template I got the error "jinja2.exceptions.UndefinedError: 'url_for' is undefined". 'url_for()' works absolutely fine when used with templates in Flask Applications.

The template looks like this:

{% extends "login_auth/base.html" %}
{% block title %} ProjectName {% endblock %}
{% block style %} 
    <link rel="stylesheet" href="{{url_for('static/login_auth', filename='index_stl.css')}}">    
    <script src="{{ url_for('static/login_auth', filename='index.js') }}"></script>
{% endblock %}

The Traceback is as follows:

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
  34.             response = get_response(request)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  115.                 response = self.process_exception_by_middleware(e, request)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  113.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/home/ParserMouth/folder1/folder2/ProjectName/ProjectName/login_auth/views.py" in index
  10.     return render(request,"login_auth/index.html")  # index.html will be welcome screen

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/django/shortcuts.py" in render
  36.     content = loader.render_to_string(template_name, context, request, using=using)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/django/template/loader.py" in render_to_string
  62.     return template.render(context, request)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/django/template/backends/jinja2.py" in render
  71.         return self.template.render(context)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/jinja2/asyncsupport.py" in render
  76.             return original_render(self, *args, **kwargs)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/jinja2/environment.py" in render
  1008.         return self.environment.handle_exception(exc_info, True)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/jinja2/environment.py" in handle_exception
  780.         reraise(exc_type, exc_value, tb)

File "/home/ParserMouth/folder1/folder2/ProjectName/myvenv/lib/python3.6/site-packages/jinja2/_compat.py" in reraise
  37.             raise value.with_traceback(tb)

File "/home/ParserMouth/folder1/folder2/ProjectName/ProjectName/login_auth/jinja2/login_auth/index.html" in top-level template folder2
  1. {% extends "login_auth/base.html" %}

File "/home/ParserMouth/folder1/folder2/ProjectName/ProjectName/login_auth/jinja2/login_auth/base.html" in top-level template folder2
  12.         {% block style %} {% endblock %}    

File "/home/ParserMouth/folder1/folder2/ProjectName/ProjectName/login_auth/jinja2/login_auth/index.html" in block "style"
  4.     <link rel="stylesheet" href="{{ url_for('static/login_auth', filename='index_stl.css') }}">

Exception Type: UndefinedError at /
Exception Value: 'url_for' is undefined

I want to know how to solve this problem. Thanks in advance.

@VoteCoffee sir this question is specific to django.

EternalObserver
– EternalObserver

2021-04-02 08:32:02 +00:00
Commented Apr 2, 2021 at 8:32 — EternalObserver
– EternalObserver, Commented Apr 2, 2021 at 8:32

EternalObserver · Accepted Answer · 2019-11-05 14:08:46Z

3

I figured out answer for my question. The problem occurred because 'url_for' function is provided by Flask and not Jinja2. So You need to do a little bit of configuration to load static files in your templates. 1. Add jinja2.py in Project's default app and add following code in it:

from django.contrib.staticfiles.storage import staticfiles_storage
from django.urls import reversefrom jinja2 import Environmentdef environment(**options):
    env = Environment(**options)
    env.globals.update({
        ‘static’: staticfiles_storage.url,
        ‘url’: reverse,
    })
 return env

After this you need to replace:

<link rel="stylesheet" href="{{url_for('static/login_auth', filename='index_stl.css')}}">    
<script src="{{ url_for('static/login_auth', filename='index.js') }}"></script>

with this:

<link rel=”stylesheet” href="{{ static('login_auth/index.css') }}">
<script src="{{ static('login_auth/index.js') }}"></script>

Reference:Using Jinja2 with Django

answered Nov 5, 2019 at 14:08

EternalObserver

5951 gold badge8 silver badges21 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

AzamAbbasi Over a year ago

im facing same error on flask while rendering jinja2. it gives url_for undefined. any idea about flask?

EternalObserver Over a year ago

@Harley check whether you are importing static files and have jinja2 configured properly in your virtualenv. As far as I can say you should not face this issue as you're using flask and not django.

Karishma Sukhwani Over a year ago

@AzamAbbasi hopefully you have found the answer by now but in case someone is looking for flask version then, while rendering the template you can pass url_for of flask. e.g. env.get_template('xyz.html').render(url_for=url_for)

zakk616 · Accepted Answer · 2021-12-19 14:33:03Z

1

i think you have imported

from jinja2 import Environment
from jinja2.loaders import FileSystemLoader

font-end if looking for {{ url_for() }} in jinja2 where it is not available

try to resolve it using back-end logic like:

csslink = url_for('static/login_auth', filename='index_stl.css')
jslink = url_for('static/login_auth', filename='index.js')

return tmpl.render(csslink = csslink, jslink = jslink )

and on front-end

<link rel="stylesheet" href="{{ csslink }}">    
<script src="{{ jslink }}"></script>

answered Dec 19, 2021 at 14:33

zakk616

1,57210 silver badges15 bronze badges

Comments

BleuBizarre · Accepted Answer · 2019-11-05 13:00:52Z

-2

I think you are looking for the URL filter

if you have this in your urls :

path('client/<int:id>/', app_views.client, name='app-views-client')

you can call it this way :

{% url 'app-views-client' client.id %}

info : https://docs.djangoproject.com/fr/2.2/ref/templates/builtins/#url

answered Nov 5, 2019 at 13:00

BleuBizarre

3682 silver badges17 bronze badges

3 Comments

EternalObserver Over a year ago

Sir, as I have mentioned in my question I'm using Jinja2 templating in my project, not django's default template. I'm using "url_for" to load my static file in my template and not trying to link to get url for a view in django app.

BleuBizarre Over a year ago

my bad ! Can you try something similar to this : {{url(‘app-views-client’, args=[client.id])}} or {{url('app-views-client', kwargs={'id':client.id}}}

EternalObserver Over a year ago

Ya sure. I'll try and revert back.

Collectives™ on Stack Overflow

UndefinedError: 'url_for' is undefined; while using Jinja2 in Django

3 Answers 3

3 Comments

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related