django-dbsettings/dbsettings/functions.py

from .models import Setting

from django.utils.functional import LazyObject, empty

class DBSettings:
    def __init__(self):
        for setting in Setting.objects.all():
            if setting.key.isupper():
                setattr(self, setting.key, setting.value)

    def __setattr__(self, name, value):
        setting, _ = Setting.objects.get_or_create(key=name)
        setting.value = value
        setting.save()

        self.__dict__[name] = value

    def __delattr__(self, name):
        setting = Setting.objects.get(key=name)
        setting.delete()

        self.__dict__.pop(name, None)

class LazyDBSettings(LazyObject):
    def _setup(self):
        self._wrapped = DBSettings()

    def __getattr__(self, name):
        if self._wrapped is empty:
            self._setup()

        val = getattr(self._wrapped, name)

        self.__dict__[name] = val
        return val

    def __setattr__(self, name, value):
        if name == "_wrapped":
            self.__dict__.clear()
        else:
            self.__dict__.pop(name, None)

        super().__setattr__(name, value)

    def __delattr__(self, name):
        super().__delattr__(name)
        self.__dict__.pop(name, None)

def getValue(key, default=None):
    try:
        return Setting.objects.get(key=key).value
    except:
        if default is None:
            raise KeyError("No such setting: %s" % key)
        else:
            return default

def setValue(key, value):
    obj = Setting.objects.get_or_create(key=key)[0] # pylint: disable=E1101
    obj.value = value
    obj.save()
    return True

dbsettings = LazyDBSettings()