COMPRESS_PRECOMPILERS break css url()

[domoritz]

Since the precompiled files are served from another location, relative links in css files do not work anymore.

The Problem can be solved by setting the output dir to an empty string.

COMPRESS_OUTPUT_DIR = ''

However, it would be great to have processed urls in the css file that link to the right locations of images.

[jezdez]

I'm not sure I understand correctly, can you provide a test case showing the problem?

[domoritz]

I have a scss precompiler for my scss files. It has to be executed even in development since the browser can't handle scss files.

COMPRESS_PRECOMPILERS = (
    ('text/x-scss', 'pyscss -C {infile}'),
)

As a result I get a precompiled css for each scss file. So far so good. however, the problem occurs when I reference images with url() inside my scss files.Since these are not processed, relative urls, such as ../images/foo.png won't work anymore because the precompiled css files are served from another location and the images cannot be accessed. The problem is for example that urls will be relative to the CACHE location and not the static location in case you are using django.contrib.staticfiles.

My config looks like this:

DEBUG = True
STATIC_URL = '/static/'
COMPRESS_ENABLED = False
STATICFILES_FINDERS = (
    'django.contrib.staticfiles.finders.FileSystemFinder',
    'django.contrib.staticfiles.finders.AppDirectoriesFinder',
    # other finders..
    'compressor.finders.CompressorFinder',
)

this works:

COMPRESS_OUTPUT_DIR = ''

this does not:

COMPRESS_OUTPUT_DIR = 'CACHE'

[reinout]

Yes, this is an issue (at least, I have the same problem). I'm using twitter bootstrap as a css framework. That contains less stylesheets and I handle those with compressor.

But the sprite file with icons that's included in twitter bootstrap is missing when setting COMPRESS_ENABLED=False (as I'm developing) because the icon .png file isn't moved to the CACHE/ directory.

[domoritz]

It would be a solution to serve all static content from the CACHE location while DEBUG=True.

[jezdez]

Well, for the record, that's why the CssAbsoluteFilter exists, to convert relative URLs to absolute ones. If you don't want to use it, it's perfectly fine to set COMPRESS_OUTPUT_DIR to an empty string. Serving files from that directory is out of scope of compressor.

[rvanlaar]

CssAbsoluteFilter does not run when COMPRESS_ENABLED = False.

In my use case I want to run the precompressor and the CssAbsoluteFilter, but I don't want to compress the css.
This is not possible since in base.py:Compressor.hunks: enabled = settings.COMPRESS_ENABLED or forced
And self.filters where is not called because enabled = False.

Is it possible to use CssAbsoluteFilter without compressing the css?

[jezdez]

It's not possible right now, no.

[Nagyman]

I've encountered this issue as well, and it makes development a bit troublesome. Setting the COMPRESS_OUTPUT_DIR to an empty string might work, but only in simple cases; any sort of deeper directory structure breaks all of the url paths in CSS files, since the pre-compilers output to COMPRESS_OUTPUT_DIR/css regardless of source location. With so many css urls being relative, you're forced to turn compression on or abandon pre-compilers.

One alternative I was brainstorming, was detecting in the file to be pre-compiled, whether or not compression is enabled and adjusting the image paths in that file...which would be an ugly hack if it was possible.

[Nagyman]

Scratch my comment. It does still apply, but I think one of the pull requests (specific commit below), will allow for the CssAbsoluteFilter, thus avoiding the issue entirely. Nice.

matthewwithanm@05f3d8c

[reinout]

Setting COMPRESS_OUTPUT_DIR to an empty directory just removes CACHE from the resulting filename. So the file still ends up in the COMPRESS_ROOT.

Setting COMPRESS_ROOT to the empty string places CACHE/css/... in the directory where you started django.

So there's no way to currently get django-compressor to create the output file in the same directory as the source file.

[chuchiperriman]

Same problem here, I think it is important

[willhardy]

My workaround for this was to add the following to the bottom of my settings:

if not COMPRESS_ENABLED:
    COMPRESS_ENABLED = True
    COMPRESS_CSS_FILTERS = ['compressor.filters.css_default.CssAbsoluteFilter']
    COMPRESS_JS_FILTERS = []

The settings are saying don't apply filters, but you want this one to apply anyway. You want some filters to get some sort of special status that makes them run whether or not COMPRESS_ENABLED is true. I imagine an attribute on the relevant filter's class might be able to tell django-compressor to always use it. This isn't ideal, because the developer won't expect things to be changed. The above mentioned approach of attaching filters to precompiler definitions might be nicer.

[anttihirvonen]

I'm doing the same as @willhardy at the moment. It works, but as the compressor runs, the JS files also are concatenated and that makes the debugging a bit harder, as the resulting file can be quite long.

It should be possible to run some filters even when COMPRESS_ENABLED = False. Or should the CssAbsoluteFilter be run as a precompiler, as it really doesn't do any compressing? The pull request #291 is somewhat related, as it would allow class-based precompilers.