Any hints on how to mix Django-Polymorphic with Parler? about django-parler HOT 5 CLOSED

Which order are you using for the inheritance? You can also set the form explicitly. The form needs to inherit the TranslatableModelForm off course.

from django-parler.

In django-fluent-pages, the following inheritance chain is used:

class UrlNodeAdminForm(MPTTAdminForm, TranslatableModelForm):
    # The form class
    pass

class UrlNodeParentAdmin(TranslatableAdmin, PolymorphicMPTTParentModelAdmin):
    # The polymorphic parent admin.
    base_model = UrlNode  

class UrlNodeChildAdmin(PolymorphicMPTTChildModelAdmin, TranslatableAdmin):
    # The polymorphic child admin.
    base_model = UrlNode
    base_form = UrlNodeAdminForm

Just for reference:

class PolymorphicMPTTParentModelAdmin(PolymorphicParentModelAdmin, MPTTModelAdmin):
    pass

class PolymorphicMPTTChildModelAdmin(PolymorphicChildModelAdmin, MPTTModelAdmin):
    pass

from django-parler.

I actually don't need django-polymorphic-tree, so I just use django-polymorphic.
I've been so far already, and for existing objects this works fine. Please have a look at https://github.com/edoburu/django-parler/blob/master/docs/polymorphicmodel.rst for details on how the models are defined.

The problem arises, when I add a new product. First I have to choose between Book or Pen. After I filled the model specific fields for the first time, and then try to save that new object, the form is rejected telling me, that the field "Type" is mandatory and that I have to choose between Book or Pen, showing me the same form as at the beginning.

This is my admin.py for testing the demo:

from django.contrib import admin
from parler.admin import TranslatableAdmin, TranslatableModelForm
from polymorphic.admin import PolymorphicParentModelAdmin, PolymorphicChildModelAdmin
from myapp.models.myproduct import BaseProduct, Book, Pen  # from docs/polymorphicmodel.rst

class BookAdmin(TranslatableAdmin, PolymorphicChildModelAdmin):
    base_form = TranslatableModelForm
    base_model = BaseProduct
    base_fields = ('code', 'price', 'name', 'slug')

class PenAdmin(TranslatableAdmin, PolymorphicChildModelAdmin):
    base_form = TranslatableModelForm
    base_model = BaseProduct
    base_fields = ('code', 'price', 'identifier',)

class BaseProductAdmin(PolymorphicParentModelAdmin):
    base_model = BaseProduct
    child_models = ((Book, BookAdmin), (Pen, PenAdmin),)
    list_display = ('code', 'price',)

admin.site.register(BaseProduct, BaseProductAdmin)

Each model admin (polymorphic, parler) by itself works fine, however combining them causes this issue. BTW, if I switch the order of inheritance, the language tabs disappear.

from django-parler.

After I filled the model specific fields for the first time, and then try to save that new object, the form is rejected telling me, that the field "Type" is mandatory and that I have to choose between Book or Pen, showing me the same form as at the beginning.

The logic for that happens in PolymorphicParentModelAdmin.add_view(). For your own debugging, please look at that code too. First of all, which Django version are you using? Can you see whether the ct_id GET parameter is passed to the next page?

BTW, if I switch the order of inheritance, the language tabs disappear.

That's caused by which modeladmin defines the change_form_template. You can overwrite it yourself too if you like, and combine both templates there.

from django-parler.

Thanks for your hints, I now fixed this bug in django-polymorphic.

One question remains. I pilfered your pattern with the add_preserved_filters. However I did not find any API docs about this in Django. Could you please point me onto some docs, where this function is described in detail.

from django-parler.