Question

Hi Stackoverflow people,

I would like to change the m2m widget in the admin pages (and later in the actual django site) to a more user friendly double list (like this one).

I understand that django.contrib.admin.widgets.FilteredSelectMultiple could do this for me. However, I have trouble to get it to work. I have added the code below to my admin.py, but the widget is not changing when I view the model in the admin app.

I have tried to adopt the code from here. Every SupplierProfile should connect to one or more countries from the WorldBorder model (based on the GeoDjango example)

Where is the flaw in the code? I can’t see why it would not be displayed.
Thank you for your help!

from django import forms
from django.contrib.admin.widgets import FilteredSelectMultiple
from django.contrib.gis import admin
from django.utils.translation import ugettext_lazy as _

from apps.profile.models import (UserProfile,
                                  SupplierProfile)
from apps.gis_data.models import WorldBorder


class WorldBorderAdmin(admin.ModelAdmin):
    filter_horizonal = ('name',)

class SupplierProfileAdminForm(forms.ModelForm):
    distribution_location_country = forms.ModelMultipleChoiceField(
        queryset = WorldBorder.objects.all(), 
            required = False,
            widget = FilteredSelectMultiple(
            verbose_name = _('Distribution Country'),
            is_stacked=False
        )
     )

    class Meta:
        model = SupplierProfile

    def __init__(self, *args, **kwargs):
        super(SupplierProfileAdminForm, self).__init__(*args, **kwargs)

        if self.instance:
          self.fields['distribution_location_country'].initial = self.instance.distribution_location_country.all()

    def save(self, commit=True):
        profile = super(SupplierProfileAdminForm, self).save(commit=False)

        profile.distribution_location_country = self.cleaned_data['distribution_location_country']

        if commit:
            profile.save()
            profile.save_m2m()

        return profile

class SupplierProfileAdmin(admin.ModelAdmin):
    form = SupplierProfileAdminForm

admin.site.register(SupplierProfile, admin.OSMGeoAdmin)

Updated code of admin.py

Is it possible to define the double list as stated below? “distribution_location_country” is the m2m field in my SupplierProfile. For some reason, it is still not coming through.

from django import forms
from django.contrib.admin.widgets import FilteredSelectMultiple
from django.contrib.gis import admin

class SupplierProfileAdmin(admin.OSMGeoAdmin):
    filter_horizontal = ('distribution_location_country', )

admin.site.register(SupplierProfile, SupplierProfileAdmin)

Answer 1

Your register line seems to be wrong:

admin.site.register(SupplierProfile, admin.OSMGeoAdmin)

doesn’t register your customized SupplierProfileAdmin with your model.

Perhaps you want the base class of SupplierProfileAdmin to be OSMGeoAdmin instead of ModelAdmin:

class SupplierProfileAdmin(admin.OSMGeoAdmin):
    form = SupplierProfileAdminForm

and your register line to be

admin.site.register(SupplierProfile, SupplierProfileAdmin)

Also, I’m not sure about this, but you might just be able to use

filter_horizonal = ('name_of_the_m2m_field_on_the_model', )

on your SupplierProfileModel instead of that custom field on the form?