Django Admin - add collapse to a fieldset, but have it start expanded

Question

Is there a way to make a fieldset collapsible, but start expanded? When you add collapse to the fieldset classes, it gets the functionality but starts collapsed. I've taken a look at the JS that shows/hides the fieldset content, but it doesn't look like there's anything in there to do what I'd like it to, so I'm assuming I'll have to roll my own. Just wanted to check before I went through that effort.

Answer 1

admin.py:

class PageAdmin(admin.ModelAdmin):
    fieldsets = (
        (None, {
            'fields': ('title', 'content', )
        }),
        ('Other Informations', {
            'classes': ('collapse', 'open'),
            'fields': ('slug', 'create-date',)
        }),
    )

templates/app_label/model_name/change_form.html:

{% extends "admin/model_name/change_form.html" %}

{% block extrahead %}
    {{ block.super }}
    <script src="{{ STATIC_URL }}admin/js/collapse-open.js" type="text/javascript"></script>
{% endblock %}

static/admin/js/collapse-open.js:

(function($) {
    $(document).ready(function() {
        $('fieldset.collapse.open').removeClass('collapsed');
    });
})(django.jQuery);