Django Middleware providing a mechanism for triggering warnings about template context keys that do not get used while rendering the template.

Full documentation on read the docs.

1. Install the package:

python -m pip install django-unused-context

2. Add the middleware to your Django settings.py file:

MIDDLEWARE = [


    'django_unused_context.middleware.UnusedContextMiddleware',

    ...
]

3. Ensure that DEBUG is set to True in your Django settings file.

DEBUG = True

Usage is automatic once the middleware is added. On each response that renders a template, any variables that were added to the template's context and then not used in the template rendering will be added to an internal set that will be both logged out and raise warnings. This is useful for knowing that all variables being sent to a template are being used.

The package has a couple of configuration options available to you. The options can be set by adding the associated option and its value into your settings file for Django.

Default: False
The tool will only show warnings and log out messages when the project's settings has DEBUG = True. If you would like to have unused context variables logged out and raise warnings regardless of whether DEBUG = True, set this setting to True.

This is useful for having tests output any unused context variables. Since tests are normally run with DEBUG set to False, you will never see output from this tool when running tests. If you would like to see this output when running tests as well you can, set this setting to True.

NOTE: It is strongly Encouraged that you do NOT turn this setting on for a project that is in production as it will slow down the site and do unnecessary logging.

DJANGO_UNUSED_CONTEXT_ALWAYS = True

Default: [] (Empty List)
The tool comes with some default keys that are automatically ignored regardless of whether they are used or not in a template. Many of these are provided by Django automatically and thus often times may not be used in a template. Rather than constantly seeing these, it seemed more reasonable to ignore them.

The predefined keys to ignore include:

'block',                  # block.super not called in overridden template.
'csrf_token',             # Given to all templates.
'DEFAULT_MESSAGE_LEVELS', # Given to all templates using messages framework.
'False',                  # Given to all templates.
'forloop',                # Given to templates with a for loop.
'is_paginated',           # Included by ListView and may not need pagination.
'None',                   # Given to all templates.
'page_obj',               # Included by ListView and may not need pagination.
'paginator',              # Included by ListView and may not need pagination.
'perms',                  # Given to login_required templates.
'root_urlconf',           # Given to exception pages for 404.
'settings',               # Likely to be given to templates and not used.
'site',                   # Given to the login page and may not be used.
'site_name',              # Given to the login page and may not be used.
'True',                   # Given to all templates.
'view',                   # Given to built-in password reset page.

If you would like to add additional keys to ignore that are specific to your project, you can do that here. Be sure to list each key in the list as a string.

DJANGO_UNUSED_CONTEXT_IGNORE = [
    'errors'
]