planetstack/core/models/plcorebase.py

   1 import os
   2 from django.db import models
   3 from django.forms.models import model_to_dict
   4 from observer.event_manager import EventSender
   5
   6
   7 class PlCoreBase(models.Model):
   8
   9         created = models.DateTimeField(auto_now_add=True)
  10         updated = models.DateTimeField(auto_now=True)
  11
  12         class Meta:
  13                 abstract = True
  14                 app_label = "core"
  15
  16         def __init__(self, *args, **kwargs):
  17                 super(PlCoreBase, self).__init__(*args, **kwargs)
  18                 self.__initial = self._dict
  19
  20         @property
  21         def diff(self):
  22                 d1 = self.__initial
  23                 d2 = self._dict
  24                 diffs = [(k, (v, d2[k])) for k, v in d1.items() if v != d2[k]]
  25                 return dict(diffs)
  26
  27         @property
  28         def has_changed(self):
  29                 return bool(self.diff)
  30
  31         @property
  32         def changed_fields(self):
  33                 return self.diff.keys()
  34
  35         def get_field_diff(self, field_name):
  36                 return self.diff.get(field_name, None)
  37
  38         def delete(self, *args, **kwds):
  39                 super(PlCoreBase, self).delete(*args, **kwds)
  40
  41                 EventSender().fire({'delete_flag':True,'model':self.__name__})
  42
  43         def save(self, *args, **kwargs):
  44                 super(PlCoreBase, self).save(*args, **kwargs)
  45
  46                 # Tell the observer that the source database has been updated
  47                 EventSender().fire()
  48
  49                 self.__initial = self._dict
  50
  51         @property
  52         def _dict(self):
  53                 return model_to_dict(self, fields=[field.name for field in
  54                                                          self._meta.fields])
  55
  56
  57