Setting up STATIC_URL dynamically for Subversion users

If you set STATIC_URL to a static value, then each time you update a CSS file, a JavaScript file, or an image, you will need to clear the browser cache in order to see the changes. There is a trick to work around clearing the browser's cache. It is to have the revision number of the version control system shown in STATIC_URL. Whenever the code is updated, the visitor's browser will force the loading of all-new static files.

This recipe shows how to put a revision number in STATIC_URL for Subversion users.

Getting ready

Make sure that your project is under the Subversion version control and you have BASE_DIR defined in your settings, as shown in the Defining relative paths in the settings recipe.

Then, create the utils module in your Django project, and also create a file called misc.py there.

How to do it...

The procedure to put the revision number in the STATIC_URL settings consists of the following two steps:

1. Insert the following content:

# utils/misc.py
import subprocess


def get_media_svn_revision(absolute_path):
    repo_dir = absolute_path
    svn_revision = subprocess.Popen(
        "svn info | grep 'Revision' | awk '{print $2}'",
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE, 
        shell=True,
        cwd=repo_dir,
        universal_newlines=True)
    rev = svn_revision.communicate()[0].partition('\n')[0]
    return rev

2. Modify the settings.py file and add the following lines:

# settings.py
# ... somewhere after BASE_DIR definition ...
from utils.misc import get_media_svn_revision
STATIC_URL = f'/static/{get_media_svn_revision(BASE_DIR)}/'

How it works...

The get_media_svn_revision() function takes the absolute_path directory as a parameter and calls the svn information shell command in that directory to find out the current revision. We pass BASE_DIR to the function, as we are sure that it is under version control. Then, the revision is parsed, returned, and included in the STATIC_URL definition.

See also

• The Setting up STATIC_URL dynamically for Git users recipe
• The Setting the Subversion ignore property recipe