Keeping filters in Django Admin

Question

What I would like to achive is:

• I go to admin site, apply some filters to the list of objects
• I click and object edit, edit, edit, hit \'Save\'

Answer 1

There's a simple hack to do this, but it's not a general solution and requires modifying every ModelAdmin which you want to support this. Maybe there is a general way to do this, but I've not spent the time to solve it on a general level.

The first step is to write a custom FilterSpec for the filter (see Harley's post for links that will help) which saves the chosen filter value in the session (and deletes it when no longer wanted).

# in cust_admin/filterspecs.py
from django.contrib.admin.filterspecs import FilterSpec, ChoicesFilterSpec

class MyFilterSpec(ChoicesFilterSpec):

    def __init__(self, f, request, params, model, model_admin):
        super(MyFilterSpec, self).__init__(f, request, params, model,
                                           model_admin)
        if self.lookup_val is not None:
            request.session[self.lookup_kwarg] = self.lookup_val
        elif self.lookup_kwarg in request.session:
            del(request.session[self.lookup_kwarg])

# Register the filter with a test function which will apply it to any field
# with a my_filter attribute equal to True
FilterSpec.filter_specs.insert(0, (lambda f: getattr(f, 'my_filter', False),
                               MyFilterSpec))

You must import the module this is in somewhere, for example your urls.py:

# in urls.py
from cust_admin import filterspecs

Set a property on the field you want to apply the filter to:

# in models.py
class MyModel(models.Model):
    my_field = Models.IntegerField(choices=MY_CHOICES)
    my_field.my_filter = True

In a custom ModelAdmin class, override the change_view method, so that after the user clicks save, they are returned to the list view with their filter field value added to the URL.

class MyModelAdmin(admin.ModelAdmin):
    def change_view(self, request, object_id, extra_context=None):
        result = super(MyModelAdmin, self).change_view(request, object_id,
                                                       extra_context)
        if '_save' in request.POST:
            if 'my_field__exact' in request.session:
                result['Location'] = '/admin/myapp/mymodel/?my_field__exact=%s' \
                                     % request.session['my_field__exact']
        return result