import functools
from django.contrib.contenttypes.models import ContentType
from apis_core.relations.models import Relation
[docs]
def is_relation(ct: ContentType) -> bool:
mc = ct.model_class()
return (
issubclass(mc, Relation)
and hasattr(mc, "subj_model")
and hasattr(mc, "obj_model")
)
[docs]
@functools.cache
def relation_content_types(
subj_model=None, obj_model=None, any_model=None, combination=(None, None)
) -> set[ContentType]:
allcts = list(
filter(
lambda contenttype: contenttype.model_class() is not None,
ContentType.objects.all(),
)
)
relationcts = list(filter(lambda contenttype: is_relation(contenttype), allcts))
if subj_model is not None:
relationcts = list(
filter(
lambda contenttype: subj_model in contenttype.model_class().subj_list(),
relationcts,
)
)
if obj_model is not None:
relationcts = list(
filter(
lambda contenttype: obj_model in contenttype.model_class().obj_list(),
relationcts,
)
)
if any_model is not None:
relationcts = list(
filter(
lambda contenttype: any_model in contenttype.model_class().obj_list()
or any_model in contenttype.model_class().subj_list(),
relationcts,
)
)
if all(combination):
left, right = combination
rels = list(
filter(
lambda contenttype: right in contenttype.model_class().obj_list()
and left in contenttype.model_class().subj_list(),
relationcts,
)
)
rels.extend(
list(
filter(
lambda contenttype: left in contenttype.model_class().obj_list()
and right in contenttype.model_class().subj_list(),
relationcts,
)
)
)
relationcts = rels
return set(relationcts)
[docs]
@functools.cache
def relation_match_target(relation, target: ContentType) -> bool:
if relation.forward and relation.obj_content_type == target:
return True
if not relation.forward and relation.subj_content_type == target:
return True
return False
[docs]
@functools.cache
def get_all_relation_subj_and_obj() -> list[ContentType]:
"""
Return the model classes of any model that is in some way
connected to a relation - either as obj or as subj
Returns:
list[ContentType]: A list of unique ContentTypes for related models.
"""
related_models = set()
for rel in relation_content_types():
related_models.update(rel.model_class().subj_list())
related_models.update(rel.model_class().obj_list())
return [ContentType.objects.get_for_model(item) for item in related_models]