How to replace content_type and object_id fields by a field with actual object in admin inline?

[Anton Ponomarenko]

I have inline, which shows data of contenttype model, so instead of real objects, I see content_type and object_id fields. I can exclude these fields - this is not a problem, but also I want to get real current object as selected with other Places in a dropdown list. Could anyone tell me, how can I do this?

Model:

class Criterias(models.Model):
    name = ...

class Places(models.Model):
    name = ...

class PlacesToCriterias(models.Model):
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey()

    criteria_group = models.ForeignKey(Criterias)

Admin:

class CriteriaPlacesInlineAdmin(admin.TabularInline):
    model = PlacesToCriterias

class CriteriasAdmin(admin.ModelAdmin):
    inlines = [CriteriaPlacesInlineAdmin]

admin.site.register(Criterias, CriteriasAdmin)

I can add to CriteriaPlacesInlineAdmin a form, something like:

class CriteriaPlacesChoicesFieldForm(forms.ModelForm):
    places = forms.ModelChoiceField(PlaceTypesGroups.objects.all(), label='place')

but how can I pass\add object_id to this form\query in order to get 'selected' place in the dropdown list?

[Tim Graham]

Something like https://pypi.python.org/pypi/django-genericforeignkey? Search "django admin generic foreign key widget" for other possibilities.

[Anton Ponomarenko]

Found solution.

Add form to admin.TabularInline:

class CriteriaPlacesInlineAdmin(admin.TabularInline):
    model = PlacesToCriterias

    form = CriteriaPlacesChoicesFieldForm  # <- ADDED FORM

class CriteriasAdmin(admin.ModelAdmin):
    inlines = [CriteriaPlacesInlineAdmin]

admin.site.register(Criterias, CriteriasAdmin)

Form:

class CriteriaPlacesChoicesFieldForm(forms.ModelForm):
    ct_place_type = ContentType.objects.get_for_model(PlaceTypesGroups)

    object_id = forms.ModelChoiceField(PlaceTypesGroups.objects.all(), label='places')
    content_type = forms.ModelChoiceField(ContentType.objects.all(), initial=ct_place_type, widget=forms.HiddenInput())

    def clean_object_id(self):
        return self.cleaned_data['object_id'].pk

    def clean_content_type(self):
        return self.ct_place_type