Using Django RelatedField for custom join queries?

Hi all,

I've asked this question on stackoverflow (http://stackoverflow.com/questions/18913661/using-django-relatedfield-for-custom-join-queries),

but figured it might be better to post it here:

I'm curious whether a RelatedField can be used to cause custom join queries.

I would like to apply this in django-parler (https://github.com/edoburu/django-parler), a multilingual app for Django.

For example, when "slug" is a translated field, I would like to have:

    MyModel.objects.filter(slug="foo")

to operate as:

    MyModel.objects.fiter(translations__slug="foo")

under the hood. This is possible with the API of the RelatedField class for example?

I noticed there are several API hooks in the RelatedField class, such as m2m_reverse_field_name(), m2m_target_field_name(), m2m_column_name(), extra_filters() etc.. which are used in the GenericRelation and django-taggit's TaggableManager classes but I have no idea how these work.

N.B. Regular field access on instances is covered in django-parler (using descriptors that proxy to calls to the translated table), and I would love to extend support to ORM queries as well.

Best regards,

Diederik