6.4. Admin Filters

• list_filter

>>> 
... class SalaryFilter(admin.SimpleListFilter):
...     title = _('Salary')
...     parameter_name = 'salary'
...
...     def lookups(self, request, model_admin):
...         return (
...             ('low', _('Low')),
...             ('medium', _('Medium')),
...             ('high', _('High')),
...         )
...
...     def queryset(self, request, queryset):
...         match self.value():
...             case 'low': return queryset.filter(salary__lt=5_000)
...             case 'medium': return queryset.filter(salary__gte=5_000, salary__lt=10_000)
...             case 'high': return queryset.filter(salary__gte=10_000)
...
...
... @admin.register(Employee)
... class EmployeeAdmin(BaseAdmin):
...     list_filter = [SalaryFilter]

6.4.1. Use Case - 0x01

>>> 
... from django.contrib import admin
... from django.utils.translation import gettext_lazy as _
... from datetime import date
...
...
... class AgeFilter(admin.SimpleListFilter):
...     # Human-readable title which will be displayed in the
...     # right admin sidebar just above the filter options.
...     title = _('Age')
...
...     # Parameter for the filter that will be used in the URL query.
...     parameter_name = 'age'
...
...     def lookups(self, request, model_admin):
...         return [
...             ('unknown', _('Not Specified')),
...             ('junior', _('0-18')),
...             ('adult', _('18-65')),
...             ('senior', _('65+')),
...         ]
...
...     def queryset(self, request, queryset):
...         if self.value() == 'unknown':
...             return queryset.filter(birthdate=None)
...         if self.value() == 'junior':
...            start = date.today() - datetime.timedelta(days=0*365)
...            end = date.today() - datetime.timedelta(days=18*365)
...            return queryset.filter(birthdate__gte=start, birthdate__lt=end)
...         if self.value() == 'adult':
...            start = date.today() - datetime.timedelta(days=18*365)
...            end = date.today() - datetime.timedelta(days=65*365)
...            return queryset.filter(birthdate__gte=start, birthdate__lt=end)
...         if self.value() == 'senior':
...            start = date.today() - datetime.timedelta(days=65*365)
...            return queryset.filter(birthdate__gte=start)