Creating Custom Filters for list_filter in Django Admin

Question

I would like to make custom filters for django admin instead of the normal 'is_staff' and 'is_superuser'. I have read this list_filter in Django docs. Custom Filters work in this way:

from datetime import date  from django.utils.translation import ugettext_lazy as _ from django.contrib.admin import SimpleListFilter  class DecadeBornListFilter(SimpleListFilter):     # Human-readable title which will be displayed in the     # right admin sidebar just above the filter options.     title = _('decade born')      # Parameter for the filter that will be used in the URL query.     parameter_name = 'decade'      def lookups(self, request, model_admin):         """         Returns a list of tuples. The first element in each         tuple is the coded value for the option that will         appear in the URL query. The second element is the         human-readable name for the option that will appear         in the right sidebar.         """         return (             ('80s', _('in the eighties')),             ('90s', _('in the nineties')),         )      def queryset(self, request, queryset):         """         Returns the filtered queryset based on the value         provided in the query string and retrievable via         `self.value()`.         """         # Compare the requested value (either '80s' or '90s')         # to decide how to filter the queryset.         if self.value() == '80s':             return queryset.filter(birthday__gte=date(1980, 1, 1),                                     birthday__lte=date(1989, 12, 31))         if self.value() == '90s':             return queryset.filter(birthday__gte=date(1990, 1, 1),                                     birthday__lte=date(1999, 12, 31))  class PersonAdmin(ModelAdmin):     list_filter = (DecadeBornListFilter,) 

But i have already made custom functions for list_display like this:

def Student_Country(self, obj):     return '%s' % obj.country Student_Country.short_description = 'Student-Country' 

Is it possible i could use the custom functions for list_display in list_filter instead of writing a new custom function for list_filter? Any suggestions or improvements are welcome.. Need some guidance on this... Thanks...

Answer 1

You can indeed add custom filters to admin filters by extending SimpleListFilter. For instance, if you want to add a continent filter for 'Africa' to the country admin filter used above, you can do the following:

In admin.py:

from django.contrib.admin import SimpleListFilter  class CountryFilter(SimpleListFilter):     title = 'country' # or use _('country') for translated title     parameter_name = 'country'      def lookups(self, request, model_admin):         countries = set([c.country for c in model_admin.model.objects.all()])         return [(c.id, c.name) for c in countries] + [           ('AFRICA', 'AFRICA - ALL')]      def queryset(self, request, queryset):         if self.value() == 'AFRICA':             return queryset.filter(country__continent='Africa')         if self.value():             return queryset.filter(country__id__exact=self.value())  class CityAdmin(ModelAdmin):     list_filter = (CountryFilter,)