forum/settings/base.py

   1 import django.dispatch
   2 from django.utils.encoding import force_unicode
   3 from datetime import datetime, timedelta
   4 import logging
   5
   6 TMP_MINICACHE_SECONDS = 5
   7
   8 class SettingSet(list):
   9     def __init__(self, name, title, description, weight=1000, markdown=False):
  10         self.name = name
  11         self.title = title
  12         self.description = description
  13         self.weight = weight
  14         self.markdown = markdown
  15
  16
  17 class BaseSetting(object):
  18     @classmethod
  19     def add_to_class(cls, name):
  20         def wrapper(self, *args, **kwargs):
  21             return self.value.__getattribute__(name)(*args, **kwargs)
  22
  23         setattr(cls, name, wrapper)
  24
  25     def __init__(self, name, default, set=None, field_context=None):
  26         self.name = name
  27         self.default = default
  28         self.field_context = field_context or {}
  29
  30         self._temp = None
  31
  32         if set is not None:
  33             if not set.name in Setting.sets:
  34                 Setting.sets[set.name] = set
  35
  36             Setting.sets[set.name].append(self)
  37
  38     def __str__(self):
  39         return str(self.value)
  40
  41     def __unicode__(self):
  42         return unicode(self.value)
  43
  44     @property
  45     def value(self):
  46         if self._temp:
  47             v, exp = self._temp
  48             if exp + timedelta(seconds=TMP_MINICACHE_SECONDS) > datetime.now():
  49                 return v
  50
  51         from forum.models import KeyValue
  52
  53         try:
  54             kv = KeyValue.objects.get(key=self.name)
  55             v = kv.value
  56             self._temp = (v, datetime.now() + timedelta(seconds=TMP_MINICACHE_SECONDS))
  57             return v
  58         except KeyValue.DoesNotExist:
  59             self._temp = (self.default, datetime.now() + timedelta(seconds=TMP_MINICACHE_SECONDS))
  60         except Exception, e:
  61             logging.error("Error retrieving setting from database (%s): %s" % (self.name, str(e)))
  62
  63         return self.default
  64
  65     def set_value(self, new_value):
  66         new_value = self._parse(new_value)
  67         self._temp = None
  68         self.save(new_value)
  69
  70     def save(self, value):
  71         from forum.models import KeyValue
  72
  73         try:
  74             kv = KeyValue.objects.get(key=self.name)
  75         except KeyValue.DoesNotExist:
  76             kv = KeyValue(key=self.name)
  77         except Exception, e:
  78             logging.error("Error savin setting to database (%s): %s" % (self.name, str(e)))
  79             return
  80
  81         kv.value = value
  82         kv.save()
  83
  84     def to_default(self):
  85         self.set_value(self.default)
  86
  87     def _parse(self, value):
  88         if not isinstance(value, self.base_type):
  89             try:
  90                 return self.base_type(value)
  91             except:
  92                 pass
  93         return value
  94
  95 class AnyTypeSetting(BaseSetting):
  96      def _parse(self, value):
  97         return value
  98
  99
 100 class Setting(object):
 101     emulators = {}
 102     sets = {}
 103
 104     def __new__(cls, name, default, set=None, field_context=None):
 105         if default is None:
 106             return AnyTypeSetting(name, default, set, field_context)
 107
 108         deftype = type(default)
 109
 110         if deftype in Setting.emulators:
 111             emul = Setting.emulators[deftype]
 112         else:
 113             emul = type(deftype.__name__ + cls.__name__, (BaseSetting,), {'base_type': deftype})
 114
 115             fns = [n for n, f in [(p, getattr(deftype, p)) for p in dir(deftype) if not p in dir(cls)] if callable(f)]
 116
 117             for n in fns:
 118                emul.add_to_class(n)
 119
 120             Setting.emulators[deftype] = emul
 121
 122         return emul(name, default, set, field_context)
 123
 124