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mirror of https://github.com/netbox-community/netbox.git synced 2024-05-10 07:54:54 +00:00
2020-03-14 03:03:22 -04:00

84 lines
2.3 KiB
Python

import collections
from django.db.models import Q
from django.utils.deconstruct import deconstructible
from taggit.managers import _TaggableManager
from utilities.querysets import DummyQuerySet
from extras.constants import EXTRAS_FEATURES
def is_taggable(obj):
"""
Return True if the instance can have Tags assigned to it; False otherwise.
"""
if hasattr(obj, 'tags'):
if issubclass(obj.tags.__class__, _TaggableManager):
return True
# TaggableManager has been replaced with a DummyQuerySet prior to object deletion
if isinstance(obj.tags, DummyQuerySet):
return True
return False
#
# Dynamic feature registration
#
class Registry:
"""
The registry is a place to hook into for data storage across components
"""
def add_store(self, store_name, initial_value=None):
"""
Given the name of some new data parameter and an optional initial value, setup the registry store
"""
if not hasattr(Registry, store_name):
setattr(Registry, store_name, initial_value)
registry = Registry()
@deconstructible
class FeatureQuerySet:
"""
Helper class that delays evaluation of the registry contents for the functionaility store
until it has been populated.
"""
def __init__(self, feature):
self.feature = feature
def __call__(self):
return self.get_queryset()
def get_queryset(self):
"""
Given an extras feature, return a Q object for content type lookup
"""
query = Q()
for app_label, models in registry.model_feature_store[self.feature].items():
query |= Q(app_label=app_label, model__in=models)
return query
registry.add_store('model_feature_store', {f: collections.defaultdict(list) for f in EXTRAS_FEATURES})
def extras_features(*features):
"""
Decorator used to register extras provided features to a model
"""
def wrapper(model_class):
for feature in features:
if feature in EXTRAS_FEATURES:
app_label, model_name = model_class._meta.label_lower.split('.')
registry.model_feature_store[feature][app_label].append(model_name)
else:
raise ValueError('{} is not a valid extras feature!'.format(feature))
return model_class
return wrapper