import json from django.db import models from django.db.utils import ProgrammingError, OperationalError from django.utils.translation import ugettext_lazy as _ from django.core.cache import cache from common.utils import signer class SettingQuerySet(models.QuerySet): def __getattr__(self, item): queryset = list(self) instances = [i for i in queryset if i.name == item] if len(instances) == 1: return instances[0] else: return Setting() class SettingManager(models.Manager): def get_queryset(self): return SettingQuerySet(self.model, using=self._db) class Setting(models.Model): name = models.CharField(max_length=128, unique=True, verbose_name=_("Name")) value = models.TextField(verbose_name=_("Value")) category = models.CharField(max_length=128, default="default") encrypted = models.BooleanField(default=False) enabled = models.BooleanField(verbose_name=_("Enabled"), default=True) comment = models.TextField(verbose_name=_("Comment")) objects = SettingManager() cache_key_prefix = '_SETTING_' def __str__(self): return self.name @classmethod def get(cls, item): cached = cls.get_from_cache(item) if cached is not None: return cached instances = cls.objects.filter(name=item) if len(instances) == 1: s = instances[0] s.refresh_setting() return s.cleaned_value return None @classmethod def get_from_cache(cls, item): key = cls.cache_key_prefix + item cached = cache.get(key) return cached @property def cleaned_value(self): try: value = self.value if self.encrypted: value = signer.unsign(value) if not value: return None value = json.loads(value) return value except json.JSONDecodeError: return None @cleaned_value.setter def cleaned_value(self, item): try: v = json.dumps(item) if self.encrypted: v = signer.sign(v) self.value = v except json.JSONDecodeError as e: raise ValueError("Json dump error: {}".format(str(e))) @classmethod def refresh_all_settings(cls): try: settings_list = cls.objects.all() for setting in settings_list: setting.refresh_setting() except (ProgrammingError, OperationalError): pass def refresh_setting(self): key = self.cache_key_prefix + self.name cache.set(key, self.cleaned_value, None) class Meta: db_table = "settings_setting" verbose_name = _("Setting")