[Django]-Custom Filter in Django Admin on Django 1.3 or below

you have to write a custom FilterSpec (not documentend anywhere).
Look here for an example:

http://www.djangosnippets.org/snippets/1051/

In current django development version there is the support for custom filters: https://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.list_filter

You can’t, unfortunately. Currently non-field items can not be used as list_filter entries.

Note that your admin class wouldn’t have worked even if it was a field, as a single-item tuple needs a comma: ('is_live',)

Just a sidenote: You can use the deafult ticks on Django admin more easily like this:

def is_live(self):
    if self.when_to_publish is not None:
        if ( self.when_to_publish < datetime.now() ):
            return True
    else:
        return False

is_live.boolean = True

Not an optimal way (CPU-wise) but simple and will work, so I do it this way (for my small database). My Django version is 1.6.

In admin.py:

class IsLiveFilter(admin.SimpleListFilter):
    title = 'Live'
    parameter_name = 'islive'
    def lookups(self, request, model_admin):
        return (
            ('1', 'islive'),
        )
    def queryset(self, request, queryset):
        if self.value():
            array = []
            for element in queryset:
                if element.is_live.__call__() == True:
                    q_array.append(element.id)
            return queryset.filter(pk__in=q_array)

…

class NewsItemAdmin(admin.ModelAdmin):
    form = NewsItemAdminForm
    list_display = ('headline', 'id', 'is_live')
    list_filter = (IsLiveFilter)

Key idea here is to access custom fields in a QuerySet via __call__() function.

The user supplies goods to some countries postage free. I wanted to filter those countries:

All – all countries, Yes – postage free, No – charged postage.

The main answer for this question did not work for me (Django 1.3) I think because there was no field_path parameter provided in the __init__ method. Also it subclassed DateFieldFilterSpec. The postage field is a FloatField

from django.contrib.admin.filterspecs import FilterSpec

class IsFreePostage(FilterSpec):

    def __init__(self, f, request, params, model, model_admin, field_path=None):
        super(IsFreePostage, self).__init__(f, request, params, model,
            model_admin, field_path)

        self.removes = {
            'Yes': ['postage__gt'],
            'No': ['postage__exact'],
            'All': ['postage__exact', 'postage__gt'] }

        self.links = (
            ('All', {}),
            ('Yes', {'postage__exact': 0}),
            ('No', {'postage__gt': 0}))

        if request.GET.has_key('postage__exact'):
            self.ttl = 'Yes'
        elif request.GET.has_key('postage__gt'):
            self.ttl = 'No'
        else:
            self.ttl = 'All'

    def choices(self, cl):
        for title, param_dict in self.links:
            yield {'selected': title == self.ttl,
                   'query_string': cl.get_query_string(param_dict,
                       self.removes[title]),
                   'display': title}
    def title(self):
        return 'Free Postage'

FilterSpec.filter_specs.insert(0,
    (lambda f: getattr(f, 'free_postage', False), IsFreePostage))

In self.links we supply dicts. used to construct HTTP query strings like ?postage__exact=0 for each of the possible filters. Filters I think are cumulative so if there was a previous request for ‘No’ and now we have a request for ‘Yes’ we have to remove the
‘No’ query. self.removes specifies what needs to be removed for each query. The choices method constructs the query strings, says which filter has been selected and sets the displayed name of the filter.

Here is the answer and implemented the custom filter as simple as possible this might help

Django admin date range filter