[Fixed]-Django admin add custom filter

9๐Ÿ‘

โœ…

I would go with customized FieldListFilter as it allows to bind filter to different model fields based on your requirements.

What is we actually do to implement such filter is next:

  • build lookup_kwargs gte and lte and specify them as expected_parameters
  • define choices to return empty list otherwise NotImplementedError
  • create form to care fields validation
  • create custom template which just outputs form, e.g. {{spec.form}}
  • if form is valid take itโ€™s cleaned data, filter out Nones and filter queryset otherwise do something with errors (in code below errors are silenced)

Filter code:

class StartTimeFilter(admin.filters.FieldListFilter):
    # custom template which just outputs form, e.g. {{spec.form}}
    template = 'start_time_filter.html'

    def __init__(self, *args, **kwargs):
        field_path = kwargs['field_path']
        self.lookup_kwarg_since = '%s__gte' % field_path
        self.lookup_kwarg_upto = '%s__lte' % field_path
        super(StartTimeFilter, self).__init__(*args, **kwargs)
        self.form = StartTimeForm(data=self.used_parameters, field_name=field_path)

    def expected_parameters(self):
        return [self.lookup_kwarg_since, self.lookup_kwarg_upto]

    # no predefined choices
    def choices(self, cl):
        return []

    def queryset(self, request, queryset):
        if self.form.is_valid():
            filter_params = {
                p: self.form.cleaned_data.get(p) for p in self.expected_parameters()
                if self.form.cleaned_data.get(p) is not None
            }
            return queryset.filter(**filter_params)
        else:
            return queryset

Form can be as simple as follows:

class StartTimeForm(forms.Form):

    def __init__(self, *args, **kwargs):
        self.field_name = kwargs.pop('field_name')
        super(StartTimeForm, self).__init__(*args, **kwargs)
        self.fields['%s__gte' % self.field_name] = forms.DateField()
        self.fields['%s__lte' % self.field_name] = forms.DateField()
๐Ÿ‘คbellum

6๐Ÿ‘

This isnโ€™t exactly what youโ€™ve asked for, but you could instead have the filter on the JobAdDuration modelAdmin. This way, you can get the corresponding jobs filtered according to the ad_activated and ad_finished fields. And Iโ€™ve added a link to the job field, so you can directly click it for easier navigation.

To make it a date html5 filter, Iโ€™ve used django-admin-rangefilter library.

from django.urls import reverse
from django.contrib import admin
from .models import Job, JobAdDuration
from django.utils.html import format_html
from rangefilter.filter import DateRangeFilter


@admin.register(JobAdDuration)
class JobAdDurationAdmin(admin.ModelAdmin):

    list_filter = (('ad_activated', DateRangeFilter), ('ad_finished', DateRangeFilter))
    list_display = ('id', 'job_link', 'ad_activated', 'ad_finished')

    def job_link(self, obj):
        return format_html('<a href="{}">{}</a>', reverse('admin:job_job_change', args=[obj.job.id]), obj.job.title)
    job_link.short_description = 'Job'

If you indeed want to go the existing route (filter inside JobAdmin), then things will get quite complicated.

๐Ÿ‘คshad0w_wa1k3r

3๐Ÿ‘

I have recently faced similar problem where I needed to filter data based on value from another model. This can be done using SimpleListFilter. You just need a little tweak in the lookup and queryset function. I will suggest you to install django debug toolbar so that you may know what sql queries are being executed internally by django.

#import your corresponding models first

class StartTimeFilter(SimpleListFilter):
title = ('Start date')
parameter_name = 'ad_finished'

  def lookups(self, request, model_admin):

   data = []
   qs = JobAdDuration.objects.filter()   # Note : if you do not have distinct values of ad_activated apply distinct filter here to only get distinct values
   print qs
   for c in qs:
       data.append([c.ad_activated, c.ad_activated])  # The first c.activated is the queryset condition your filter will execute on your Job model to filter data ... and second c.ad_activated is the data that will be displayed in dropdown in StartTimeFilter
   return data

  def queryset(self, request, queryset):
     if self.value():
       assigned = JobAdDuration.objects.filter(ad_activated__exact = self.value())  # add your custom filter function based on your requirement
       return Job.objects.filter(pk__in=[current.job.id for current in assigned])
     else:
       return queryset

and in list_filter

list_filter = (StartTimeFilter) # no quotes else it will search for a field in the model 'job'.
๐Ÿ‘คtrigo

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