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         enacted = models.DateTimeField(null=True, default=None)
  12
  13         class Meta:
  14                 abstract = True
  15                 app_label = "core"
  16
  17         def __init__(self, *args, **kwargs):
  18                 super(PlCoreBase, self).__init__(*args, **kwargs)
  19                 self.__initial = self._dict
  20
  21         @property
  22         def diff(self):
  23                 d1 = self.__initial
  24                 d2 = self._dict
  25                 diffs = [(k, (v, d2[k])) for k, v in d1.items() if v != d2[k]]
  26                 return dict(diffs)
  27
  28         @property
  29         def has_changed(self):
  30                 return bool(self.diff)
  31
  32         @property
  33         def changed_fields(self):
  34                 return self.diff.keys()
  35
  36         def get_field_diff(self, field_name):
  37                 return self.diff.get(field_name, None)
  38
  39         def delete(self, *args, **kwds):
  40                 super(PlCoreBase, self).delete(*args, **kwds)
  41
  42                 try:
  43                         EventSender().fire({'delete_flag':True,'model':self.__name__})
  44                 except:
  45                         # Investigate later.
  46                         pass
  47
  48
  49         def save(self, *args, **kwargs):
  50                 super(PlCoreBase, self).save(*args, **kwargs)
  51
  52                 # Tell the observer that the source database has been updated
  53                 EventSender().fire()
  54
  55                 self.__initial = self._dict
  56
  57         @property
  58         def _dict(self):
  59                 return model_to_dict(self, fields=[field.name for field in
  60                                                          self._meta.fields])
  61
  62
  63