Add unsaved changes warning to admin

[eeriksp]

Add JS

Code snippet is here, add

'use strict'
var $ = django.jQuery

at the beginning of the file.

Add script to admin views

1. Alter settings.py:

TEMPLATES = [
    {
        ...
        'DIRS': [os.path.join(BASE_DIR, 'templates'),],
        ...
    },
]

2. Add src/templates/admin/base_site.html:

{% extends 'admin/base.html' %}
{% block responsive %} {# Use 'responsive' instead of 'extrahead' in order to ensure right js files order #}
{{ block.super }}
<script type="text/javascript" src="/static/media/common/js/unsaved-changes-warning.js"></script>
{% endblock %}

3. Add tests

Alternative possibility:

see this package