Cannot delete flatpages in admin

[benkonrath]

Here's the error:

IntegrityError at /admin/fluent_pages/page/1/delete/

update or delete on table "fluent_pages_urlnode" violates foreign key constraint "master_id_refs_id_10e5f581" on table "fluent_pages_htmlpage_translation"
DETAIL:  Key (id)=(1) is still referenced from table "fluent_pages_htmlpage_translation".

Here are the versions that I'm using:

git+https://github.com/edoburu/django-fluent-pages.git@eb7f28db695706adc2695d0b24a30a051ecade52#egg=django-fluent-pages
django-mptt==0.6.1
django-parler==1.2.1
django-polymorphic-tree==1.0.1
django-wysiwyg==0.7.0

Can you see something wrong with the versions of the dependencies I'm using?

[benkonrath]

I'm using this with Django 1.6.8.

[RealBigB]

Same problem here with a custom page type derived from fluent_pages.models.Page

IntegrityError at /admin/fluent_pages/page/2/delete/
update or delete on table "fluent_pages_urlnode" violates foreign key constraint
"master_id_refs_id_03dcaa72" on table "cms_basehtmlpage_translation"
DETAIL: Key (id)=(2) is still referenced from table "cms_basehtmlpage_translation".

using :
Django==1.6.5
django-fluent-pages==0.9b4
django-mptt==0.6.1
django-parler==1.2.1
django-polymorphic==0.6
django-polymorphic-tree==1.0.1

Note that I don't have the problem on another projet using fluent_pages 0.9b2 (django-parler==1.0).

[vdboor]

I got the same issue as well.
This is caused by the translation model on the HtmlPage model (created in f2f8319)

It's possible that the admin can't see the HtmlPageTranslation model, depending on which proxy class it looks at.

I'm considering to add an on_delete=models.CASCADE to the parler generated model.

[vinnyrose]

Proxy models are not inspected for fields, as fields are not expected to be defined there. The field has to be defined onto a concrete model.

[vdboor]

Ahh, thanks for that insight! This explains a lot.

[vdboor]

Looking at https://code.djangoproject.com/ticket/16128 and https://code.djangoproject.com/ticket/18491 there is a fix in Django 1.7. As quick workaround for Django 1.6 I've improved the delete() method in 959211c

This doesn't entirely fix it off course, but makes the site usable again!

[vdboor]

This workaround/fix is now released as v0.9c1, making the latest beta versions usable again!

[benkonrath]

Thanks. Should I close the issue?

[benkonrath]

@vdboor Can we close this issue?

[vdboor]

Sorry! Yes, lets close this and see when it comes up again.

[vinnyrose]

I'm in Django 1.8. I still have to use the following code to cascade delete a page and it's children. Even though the collector seems to be finding the translations on the delete confirmation page.

@receiver(pre_delete, sender=UrlNode)
def fix_delete(sender, instance, *args, **kwargs):
    model_class = instance.polymorphic_ctype.model_class()
    if issubclass(model_class, HtmlPage):
        HtmlPageTranslation = model_class.seo_translations.related.related_model
        HtmlPageTranslation.objects.filter(master=instance.pk).delete()