DjangoRelatedField

Auto-generated for FK, one-to-one, and many-to-many relations.

It renders autocomplete in the UI.

Parameter	Description
rel_name	Relation attribute on the model
many	True for list relations
dual_list	Dual-list UI for many relations
filter_fn	Custom queryset filter

Search behavior:

• If target model defines __search_fields__, autocomplete searches by them
• Otherwise it searches string/text fields
• If none exist, it falls back to PK

class Currency(models.Model):
    __search_fields__ = ['title', 'char_code']

filter_fn receives (queryset, data, user).