python/database/record.py

   1 class Record(object):
   2     _identity_field = None
   3
   4     def get(self, field):
   5         try:
   6             return self.__getattribute__(field)
   7         except:
   8             return None
   9
  10     def _formatField(self, field):
  11         v = self.get(field)
  12         if callable(v):
  13             v = v()
  14         if hasattr(v, '__iter__'):
  15             if len(v) == 0:
  16                 return '[]'
  17             else:
  18                 return '[%d x %s]'%(len(v), type(v[0]))
  19         else:
  20             return repr(v)
  21
  22     @classmethod
  23     def _ignore(cls):
  24         return [cls._identity_field]
  25
  26     def _fields(self):
  27         ignore = self._ignore()
  28         keys = sorted(self.c.keys())
  29         return [(k,self._formatField(k)) for k in keys if k not in ignore]
  30
  31     def __repr__(self):
  32         classname = self.__class__.__name__
  33
  34         if self._identity_field:
  35             identity = self.__dict__.get(self._identity_field)
  36             identity = ' ' + (identity and repr(identity) or 'hash=%d'%hash(self))
  37         else:
  38             identity = ''
  39
  40         payload = " ".join(["%s=%s" % (k, v) for k,v in self._fields()])
  41         if len(payload) > 0:
  42             payload = ": "+payload
  43
  44         return "<%s%s%s>" % (classname, identity, payload)
  45
  46 class FormattableRecord(Record):
  47     _format = {}
  48     def _formatField(self, field):
  49         func = self._format.get(field)
  50         if func:
  51             return func(self.get(field))
  52         else:
  53             return super(FormattableRecord, self)._formatField(field)
  54
  55 class NullableRecord(FormattableRecord):
  56     _default = {}
  57     def get(self, field):
  58         v = self.__dict__.get(field)
  59         if v != None:
  60             return v
  61         else:
  62             return self._default.get(field)