make compatible with ManifestStaticFilesStorage

[jrief]

No description provided.

[mauritsvanrees]

Following the updated README from this PR fixed the incompatibility for me: setting SASS_PROCESSOR_STORAGE and SASS_PROCESSOR_STORAGE_OPTIONS to the given values. So that part of the PR is good, I would say.

The new code is not actually needed in my case it seems, but the changes make the working clearer, so it seems good. I don't really know this package though: another colleague introduced this as dependency in the project.

Quick background:

• Old situation: Django 3.0 with django-sass-processor 0.8.2. My old settings worked fine.
• New situation: Django 3.2 with django-sass-processor 1.0.1. My old settings gave errors like ValueError: Missing staticfiles manifest entry for 'images/favicon.png'. With the updated settings, it is fine again.

[Natureshadow]

Huh. I have not yet understood what the special case with the manifest storage is. Maybe we just need a second storage class the uses the ManifestStorageMixin?

I will read up on this in the following days.

N.B. It would be great if you could separate whitespace and typo changes that are not related into separate commits to make handling of potential bisects, reverts and the like in the future easier.

[jrief]

Since @mauritsvanrees and myself experienced an improvement using these code changes, I'm going to merge this now and release version 1.1.

[jrief]

@Natureshadow Without this PR, CSS files delivered by Django are unhashed. This may result in delivering outdated CSS files, since browsers and proxies are not informed to use a newer version.
Since you experienced problems in combination with S3, I changed this feature. This branch may solve both problems.

@mauritsvanrees could you please test with the new branch and report your experience.

[Natureshadow]

Without this PR, CSS files delivered by Django are unhashed

Can you please provide a minimal Django project to reproduce this issue?

[jrief]

here are my relevant configurations in settings.py:

from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent.parent

INSTALLED_APPS = [
    ...
    'sass_processor',
    ...
]

STATIC_ROOT = BASE_DIR / 'workdir/static'  # or whereever you keep temporarily compiled files
STATIC_URL = '/static/'
STATICFILES_FINDERS = [
    'django.contrib.staticfiles.finders.FileSystemFinder',
    'django.contrib.staticfiles.finders.AppDirectoriesFinder',
    'sass_processor.finders.CssFinder',
]

# if you want to access files in node_modules directly
STATICFILES_DIRS = [
    ('node_modules', BASE_DIR / 'node_modules'),
]
STATICFILES_STORAGE = 'django.contrib.staticfiles.storage.ManifestStaticFilesStorage'
# after applying this path, this will change to:
# STATICFILES_STORAGE = 'sass_processor.storage.ManifestStaticFilesStorage' 

 # optional, if you `@import ...` in SCSS from special paths, otherwise leave empty
SASS_PROCESSOR_INCLUDE_DIRS = ['path/to/static']

SASS_PROCESSOR_FAIL_SILENTLY = not DEBUG
SASS_PROCESSOR_STORAGE = 'django.contrib.staticfiles.storage.FileSystemStorage'
SASS_PROCESSOR_STORAGE_OPTIONS = {
    'location': STATIC_ROOT,
    'base_url': STATIC_URL,
}

[Natureshadow]

SASS_PROCESSOR_STORAGE = 'django.contrib.staticfiles.storage.FileSystemStorage'

That line forcefully disables the ManifestStaticFilesStorage. Leaving out this line makes compilescss use the configured STATICFILES_STORAGE and yields a style.0123456789abcd.css as expected.

The issue here is something else: ManifestStaticFilesStorage needs some manual work to generate the hashes. collectstatic does this by calling post_process on the storage after copying files.

So, the following two scenarios work flawlessly:

• DEBUG = True and using the template tag → no hash generated, no hash used, file works without hash.
• DEBUG = False and run compilecss and collectstatic → file generated at source location, hash generated on collectstatic, file works with hash.

All of this is clearly documented here.

So, I do not find the scenario that does not work as expected. What is the case that breaks for you?

[jrief]

In version 1.2.2 (and Django-4.0.6), if I use

STATICFILES_STORAGE = 'django.contrib.staticfiles.storage.ManifestStaticFilesStorage'
SASS_PROCESSOR_STORAGE = STATICFILES_STORAGE  # commenting this setting has the same effect

STATIC_ROOT = 'path/to/staticfiles'

and I delete the folder path/to/staticfiles and then run ./manage.py compilescss with DEBUG = False, then
Django complains in django/django/contrib/staticfiles/storage.py:465 with a ValueError because it can't open the manifest JSON file.

btw., overriding the value manifest_strict = False doesn't help either.

[Natureshadow]

Did you also run collectstatic?

[jrief]

Did you also run collectstatic?

after running ./manage.py compilescss. Running it before doesn't make sense.

[Natureshadow]

after running ./manage.py compilescss. Running it before doesn't make sense.

Obviously. And that still copies the file without adding it to the manifest?

[jrief]

And that still copies the file without adding it to the manifest?

No, ./manage.py compilescss aborts with a ValueError as mentioned before.