Django Compressor combines and compresses linked and inline Javascript
or CSS in a Django template into cacheable static files by using the
compress
template tag.
HTML in between {% compress js/css %}
and {% endcompress %}
is
parsed and searched for CSS or JS. These styles and scripts are subsequently
processed with optional, configurable compilers and filters.
The default filter for CSS rewrites paths to static files to be absolute
and adds a cache busting timestamp. For Javascript the default filter
compresses it using jsmin
.
As the final result the template tag outputs a <script>
or <link>
tag pointing to the optimized file. These files are stored inside a folder
and given a unique name based on their content. Alternatively it can also
return the resulting content to the original template directly.
Since the file name is dependent on the content these files can be given a far future expiration date without worrying about stale browser caches.
The concatenation and compressing process can also be jump started outside
of the request/response cycle by using the Django management command
manage.py compress
.
Django Compressor is highly configurable and extendible. The HTML parsing is done using lxml or if it's not available Python's built-in HTMLParser by default. As an alternative Django Compressor provides a BeautifulSoup and a html5lib based parser, as well as an abstract base class that makes it easy to write a custom parser.
Django Compressor also comes with built-in support for CSS Tidy, YUI CSS and JS compressor, yUglify CSS and JS compressor, the Google's Closure Compiler, a Python port of Douglas Crockford's JSmin, a Python port of the YUI CSS Compressor cssmin and a filter to convert (some) images into data URIs.
If your setup requires a different compressor or other post-processing tool it will be fairly easy to implement a custom filter. Simply extend from one of the available base classes.
More documentation about the usage and settings of Django Compressor can be found on django-compressor.readthedocs.org.
The source code for Django Compressor can be found and contributed to on github.com/django-compressor/django-compressor. There you can also file tickets.
The in-development version of Django Compressor can be installed with
pip install http://github.com/django-compressor/django-compressor/tarball/develop
.