Hi, i'm trying to use multiselect filter in modeladmin, but the rendered control is always the normal single selection dropdown. What do i need to change to get the control that i want? Also, django-jet already have this functionality built-in?
list_filter = (('education_level', IntersectionFieldListFilter), 'tutor_category',)
My multiselect list filters are based on this project: extraadminfilters... here's the code. filters.py:
from django.utils.translation import ugettext_lazy as _
from django.contrib.admin.filters import FieldListFilter
from django.db.models.fields import IntegerField, AutoField
import logging
class MultipleSelectFieldListFilter(FieldListFilter):
def __init__(self, field, request, params, model, model_admin, field_path):
self.lookup_kwarg = '%s_filter' % field_path
self.filter_statement = '%s__id' % field_path
self.lookup_val = request.GET.get(self.lookup_kwarg, None)
self.lookup_choices = field.get_choices(include_blank=False)
super(MultipleSelectFieldListFilter, self).__init__(
field, request, params, model, model_admin, field_path)
def expected_parameters(self):
return [self.lookup_kwarg]
def values(self):
"""
Returns a list of values to filter on.
"""
values = []
value = self.used_parameters.get(self.lookup_kwarg, None)
if value:
values = value.split(',')
# convert to integers if IntegerField
if type(self.field.rel.to._meta.pk) in [IntegerField, AutoField]:
values = [int(x) for x in values]
return values
def queryset(self, request, queryset):
raise NotImplementedError
def choices(self, cl):
from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
yield {
'selected': self.lookup_val is None,
'query_string': cl.get_query_string({},
[self.lookup_kwarg]),
'display': _('All')
}
for pk_val, val in self.lookup_choices:
selected = pk_val in self.values()
pk_list = set(self.values())
if selected:
pk_list.remove(pk_val)
else:
pk_list.add(pk_val)
queryset_value = ','.join([str(x) for x in pk_list])
if pk_list:
query_string = cl.get_query_string({
self.lookup_kwarg: queryset_value,
})
else:
query_string = cl.get_query_string({}, [self.lookup_kwarg])
yield {
'selected': selected,
'query_string': query_string,
'display': val,
}
class IntersectionFieldListFilter(MultipleSelectFieldListFilter):
"""
A FieldListFilter which allows multiple selection of
filters for many-to-many type fields. A list of objects will be
returned whose m2m contains all the selected filters.
"""
def queryset(self, request, queryset):
for value in self.values():
filter_dct = {
self.filter_statement: value
}
queryset = queryset.filter(**filter_dct)
return queryset
class UnionFieldListFilter(MultipleSelectFieldListFilter):
"""
A FieldListFilter which allows multiple selection of
filters for many-to-many type fields. A list of objects will be
returned whose m2m contains all the selected filters.
"""
def queryset(self, request, queryset):
filter_statement = "%s__in" % self.filter_statement
filter_values = self.values()
filter_dct = {
filter_statement: filter_values
}
if filter_values:
return queryset.filter(**filter_dct)
else:
return queryset