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, JavaScript file, or 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 setting consists of the following two steps:

1. Insert the following content:

   # utils/misc.py
   # -*- coding: UTF-8 -*-
   from __future__ import unicode_literals
   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. Then, 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 = "/static/%s/" % 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 info 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