In the admin, I would like the admin media url to be accessible from any javascript.
I already have it included in the request context.
But in order to be able to access it from an included javascript,
<script type="text/javascript">
window.__admin_media_prefix__ = "{{ ADMIN_MEDIA_URL }}";
</script>
Do I have to put something like that in a base template or is there a cleaner way to do that ?
Media (static) files are not interpreted by django in any way. On a production site python code might not even have an access to that files, as they are probably served by the frontend webserever. So you have a crazy option: use something like server side includes (SSI) to embed the variable content into choosen media files by somehow parsing the config file.
Better idea would be to have same admin media prefix scheme for every site, flexible per-site config file for your webserver of choice, where admin media files would be served from some known location: