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             self.save(self.default)
  64         except Exception, e:
  65             logging.error("Error retrieving setting from database (%s): %s" % (self.name, str(e)))
  66
  67         return self.default
  68
  69     def set_value(self, new_value):
  70         new_value = self._parse(new_value)
  71         self._temp = None
  72         self.save(new_value)
  73
  74     def save(self, value):
  75         from forum.models import KeyValue
  76
  77         try:
  78             kv = KeyValue.objects.get(key=self.name)
  79         except KeyValue.DoesNotExist:
  80             kv = KeyValue(key=self.name)
  81         except Exception, e:
  82             logging.error("Error savin setting to database (%s): %s" % (self.name, str(e)))
  83             return
  84
  85         kv.value = value
  86         kv.save()
  87
  88     def to_default(self):
  89         self.set_value(self.default)
  90
  91     def _parse(self, value):
  92         if not isinstance(value, self.base_type):
  93             try:
  94                 return self.base_type(value)
  95             except:
  96                 pass
  97         return value
  98
  99 class AnyTypeSetting(BaseSetting):
 100      def _parse(self, value):
 101         return value
 102
 103
 104 class Setting(object):
 105     emulators = {}
 106     sets = {}
 107
 108     def __new__(cls, name, default, set=None, field_context=None):
 109         if default is None:
 110             return AnyTypeSetting(name, default, set, field_context)
 111
 112         deftype = type(default)
 113
 114         if deftype in Setting.emulators:
 115             emul = Setting.emulators[deftype]
 116         else:
 117             emul = type(deftype.__name__ + cls.__name__, (BaseSetting,), {'base_type': deftype})
 118
 119             fns = [n for n, f in [(p, getattr(deftype, p)) for p in dir(deftype) if not p in dir(cls)] if callable(f)]
 120
 121             for n in fns:
 122                emul.add_to_class(n)
 123
 124             Setting.emulators[deftype] = emul
 125
 126         return emul(name, default, set, field_context)
 127
 128