purgecss_filter.py

from compressor.filters import CompilerFilter
from django.conf import settings
from pathlib import Path
from django.template.loaders.app_directories import get_app_template_dirs


COMPRESS_PURGECSS_BINARY = "purgecss"
COMPRESS_PURGECSS_ARGS = ""
COMPRESS_PURGECSS_APPS_INCLUDED = []


class PurgeCSSFilter(CompilerFilter):
    command = '{binary} --css {infile} -o {outfile} {args}'
    options = (
        ("binary",
         getattr(
             settings,
             "COMPRESS_PURGECSS_BINARY",
             COMPRESS_PURGECSS_BINARY)),
        ("args",
         getattr(
            settings,
            "COMPRESS_PURGECSS_ARGS",
            COMPRESS_PURGECSS_ARGS)),
             )

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        template_files = " ".join(self.get_all_template_files())
        self.command += " --content {}".format(template_files)

    def get_all_template_files(self):
        files = []
        apps = getattr(settings, "COMPRESS_PURGECSS_APPS_INCLUDED", COMPRESS_PURGECSS_APPS_INCLUDED)
        dirs = get_app_template_dirs('templates')
        for d in dirs:
            if 'site-packages' in str(d):
                for app in apps:
                    if app in str(d):
                        for f in Path(d).glob('**/*.html'):
                            files.append(str(f))
            else:
                for f in Path(d).glob('**/*.html'):
                    files.append(str(f))
        return files