id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
7631	Model backward inheritance in newforms admin	occulkot@…	nobody	"
{{{
#!python
class Document(models.Model):
    num = models.CharField(max_length=30)

class DocumentType(Document):
    payment_type = models.IntegerField()
    payment_date = models.DateField()
    client = models.ForeignKey(Client)

class OtherDocument(Document):
    first_field = models.CharField(max_length=111)
    second_field = models.CharField(max_length=123)

class DocumentRow(models.Model)
    document = models.ForeignKey(Document, related_name='rows')
    kind = models.CharField(max_length=30)
    date = models.DateField()
}}}
As you can see we have 2 kinds of documents - DocumentType and OtherDocument - every kind of document has same fields as ""Document"" and aditional fields. And every kind of document should hav rows.
It works perfectly in standard views but its problematic to implement in admin.
i tried

{{{
#!python
class DocumentRowAdmin(admin.TabularInline):
    extra = 10
    model = models.DocumentRow
    
class DocumentTypeAdmin(admin.ModelAdmin):
    inlines = [DocumentRowAdmin, ]

admin.register(models.DocumentType, PrzesuniecieAdmin)
admin.register(models.OtherDocument, PrzesuniecieAdmin)

}}}
And this way it only raises an exception about relationship.
Maybe some ""inline_for_parent"" option or sth?
im trying to make it working myself but im stuck in BaseModelFormSet.get_queryset method"		closed	contrib.admin	dev		fixed		mateusz@…	Design decision needed	0	0	0	0	0	0