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, can_preview=False):
  10         self.name = name
  11         self.title = title
  12         self.description = description
  13         self.weight = weight
  14         self.markdown = markdown
  15         self.can_preview = can_preview
  16
  17
  18 class BaseSetting(object):
  19     @classmethod
  20     def add_to_class(cls, name):
  21         def wrapper(self, *args, **kwargs):
  22             return self.value.__getattribute__(name)(*args, **kwargs)
  23
  24         setattr(cls, name, wrapper)
  25
  26     def __init__(self, name, default, set=None, field_context=None):
  27         self.name = name
  28         self.default = default
  29         self.field_context = field_context or {}
  30
  31         self._temp = None
  32
  33         if set is not None:
  34             self.set = set
  35
  36             if not set.name in Setting.sets:
  37                 Setting.sets[set.name] = set
  38
  39             Setting.sets[set.name].append(self)
  40
  41     def __str__(self):
  42         return str(self.value)
  43
  44     def __unicode__(self):
  45         return unicode(self.value)
  46
  47     @property
  48     def value(self):
  49         if self._temp:
  50             v, exp = self._temp
  51             if exp + timedelta(seconds=TMP_MINICACHE_SECONDS) > datetime.now():
  52                 return v
  53
  54         from forum.models import KeyValue
  55
  56         try:
  57             kv = KeyValue.objects.get(key=self.name)
  58             v = kv.value
  59             self._temp = (v, datetime.now() + timedelta(seconds=TMP_MINICACHE_SECONDS))
  60             return v
  61         except KeyValue.DoesNotExist:
  62             self._temp = (self.default, datetime.now() + timedelta(seconds=TMP_MINICACHE_SECONDS))
  63         except Exception, e:
  64             logging.error("Error retrieving setting from database (%s): %s" % (self.name, str(e)))
  65
  66         return self.default
  67
  68     def set_value(self, new_value):
  69         new_value = self._parse(new_value)
  70         self._temp = None
  71         self.save(new_value)
  72
  73     def save(self, value):
  74         from forum.models import KeyValue
  75
  76         try:
  77             kv = KeyValue.objects.get(key=self.name)
  78         except KeyValue.DoesNotExist:
  79             kv = KeyValue(key=self.name)
  80         except Exception, e:
  81             logging.error("Error savin setting to database (%s): %s" % (self.name, str(e)))
  82             return
  83
  84         kv.value = value
  85         kv.save()
  86
  87     def to_default(self):
  88         self.set_value(self.default)
  89
  90     def _parse(self, value):
  91         if not isinstance(value, self.base_type):
  92             try:
  93                 return self.base_type(value)
  94             except:
  95                 pass
  96         return value
  97
  98 class AnyTypeSetting(BaseSetting):
  99      def _parse(self, value):
 100         return value
 101
 102
 103 class Setting(object):
 104     emulators = {}
 105     sets = {}
 106
 107     def __new__(cls, name, default, set=None, field_context=None):
 108         if default is None:
 109             return AnyTypeSetting(name, default, set, field_context)
 110
 111         deftype = type(default)
 112
 113         if deftype in Setting.emulators:
 114             emul = Setting.emulators[deftype]
 115         else:
 116             emul = type(deftype.__name__ + cls.__name__, (BaseSetting,), {'base_type': deftype})
 117
 118             fns = [n for n, f in [(p, getattr(deftype, p)) for p in dir(deftype) if not p in dir(cls)] if callable(f)]
 119
 120             for n in fns:
 121                emul.add_to_class(n)
 122
 123             Setting.emulators[deftype] = emul
 124
 125         return emul(name, default, set, field_context)
 126
 127