Icons for datepicker don't show up when `_get_form_class` is executed twice for a single form

[vanschelven]

Similar to #21 but with a different cause (in fact: #21's solution might be the cause).

When the filter's _get_form_class is executed twice in the process of constructing a single form, the required JS is not produced, which leads to

• an error jQuery.Deferred exception: DateTimeShortcuts is not defined in the JS console
• the icons for the datepicker not showing up.

Code to reproduce:

@admin.register(Foo)
class FooAdmin(models.ModelAdmin):

    def get_changelist_instance(self, request):
        cl = super().get_changelist_instance(request)
        q = cl.get_queryset(request)
        return cl

    list_filter = [
        ('bar', DateRangeFilter),
    ]

The reason you might want to do the above for the curious.

django==2.2.20
django-admin-rangefilter==0.7.0

The workaround for now has been to add request.DJANGO_RANGEFILTER_ADMIN_JS_SET = False right before the get_queryset call, but this is less than optimal.

[vanschelven]

Some random thoughts from under the proverbial shower:

• Perhaps moving the "just do it once" check to a point where the form is rendered, rather than just initialized, could be a way forward.
• Since this package is reusing django's date widget, I wonder: the present package can't be the only one suffering from this particular problem, right?

[silentsokolov]

Thx, fixed on 0.8.0 version

[vanschelven]

Awesome, I'll check it out next week!

[vanschelven]

Indeed 0.8.1 fixes the problem I was experiencing, many thanks!