Custom template filter 3.2.18 -> 4.17

Using Django Mystery Errors
1

Hello hello,

I have a custom template filter that works perfectly under django 3.2.18.

When switching to django 4.1.7, I get :

django.template.exceptions.TemplateSyntaxError: Invalid filter: 'daysuntil'

Simplified version:

from django import template
from django.utils import timezone

register = template.Library()


@register.filter(name='daysuntil')
def daysuntil(d, now=timezone.now()):
    return 1

folder structure:

portal
|__ portal_core
      |__ templatetags
           |__ __init__.py
           |__ daysuntil.py
|__ __init__.py

settings:

INSTALLED_APPS += (
    <snip>
    'portal.portal_core',
)

just switching the django version causes it to break.

Any idea? something I missed in the release notes? :[

EDIT (template) =============
Exception when template is used/loaded/requested:

<snip>
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 154, in __init__
    self.nodelist = self.compile_nodelist()
                    ^^^^^^^^^^^^^^^^^^^^^^^
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 200, in compile_nodelist
    return parser.parse()
           ^^^^^^^^^^^^^^
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 484, in parse
    raise self.error(token, e)
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 482, in parse
    filter_expression = self.compile_filter(token.contents)
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 600, in compile_filter
    return FilterExpression(token, self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 698, in __init__
    filter_func = parser.find_filter(filter_name)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/env/lib/python3.11/site-packages/django/template/base.py", line 606, in find_filter
    raise TemplateSyntaxError("Invalid filter: '%s'" % filter_name)
django.template.exceptions.TemplateSyntaxError: Invalid filter: 'daysuntil'

Template:

{% load static media daysuntil %}
<snip>
{{ object.event_datetime|daysuntil }}
</snip>
2

When the exception is being raised?
When django is loaded or when a template is rendered? If the exception is raised when a template is rendered, please also post the template that uses this filter here.

3

I’m an idiot.

Wrong template… :slight_smile: