def create_intermediary_model(m2m, model, name):
is_polymorph = m2m.to_field is None
if is_polymorph:
source, target = m2m.rel.to, model
else:
source, target = model, m2m.rel.to
if source._meta.abstract:
return None
if not is_polymorph:
table = m2m.to_field.rel.through._meta.db_table
elif m2m.explicit_db_table:
table = m2m.explicit_db_table
else:
table = "%s_%s_%s_rel" % (model._meta.app_label, model.__name__.lower(), name)
on_delete = models.CASCADE if is_polymorph else models.DO_NOTHING,
attrs = dict(
obj = models.ForeignKey(source, related_name=no_related_name(), on_delete=on_delete),
rel_obj = models.ForeignKey(target, related_name=no_related_name(), on_delete=on_delete),
Meta = type('Meta', (object,), dict(
managed=is_polymorph,
db_table=table,
auto_created=model,
unique_together=('obj', 'rel_obj'),
)),
__module__ = target.__module__,
)
through = type('%s%s' % (model.__name__, camel_case(name, True)), (models.Model,), attrs)
return through
def create_intermediate_model(cls, rel_name, attrs, bases=None, meta=None):
if not meta:
meta = {}
if not bases:
bases = (models.Model,)
meta.setdefault('app_label', cls._meta.app_label)
attrs['Meta'] = type('Meta', (object,), meta)
attrs.setdefault('__module__', cls.__module__)
return type("%s%s" % (cls.__name__, camel_case(rel_name, True)), bases, attrs)
