| import datetime |
| import os |
| import sys |
| from django.db import models |
| from django.forms.models import model_to_dict |
| from django.core.urlresolvers import reverse |
| from django.forms.models import model_to_dict |
| |
| try: |
| # This is a no-op if observer_disabled is set to 1 in the config file |
| from observer import * |
| except: |
| print >> sys.stderr, "import of observer failed! printing traceback and disabling observer:" |
| import traceback |
| traceback.print_exc() |
| |
| # guard against something failing |
| def notify_observer(*args, **kwargs): |
| pass |
| |
| # This manager will be inherited by all subclasses because |
| # the core model is abstract. |
| class PlCoreBaseManager(models.Manager): |
| def get_query_set(self): |
| return super(PlCoreBaseManager, self).get_query_set().filter(deleted=False) |
| |
| # default values for created and updated are only there to keep evolution |
| # from failing. |
| class PlCoreBase(models.Model): |
| objects = PlCoreBaseManager() |
| created = models.DateTimeField(auto_now_add=True, default=datetime.datetime.now()) |
| updated = models.DateTimeField(auto_now=True, default=datetime.datetime.now()) |
| enacted = models.DateTimeField(null=True, default=None) |
| backend_status = models.CharField(max_length=140, |
| default="Provisioning in progress") |
| deleted = models.BooleanField(default=False) |
| |
| class Meta: |
| # Changing abstract to False would require the managers of subclasses of |
| # PlCoreBase to be customized individually. |
| abstract = True |
| app_label = "core" |
| |
| def __init__(self, *args, **kwargs): |
| super(PlCoreBase, self).__init__(*args, **kwargs) |
| self.__initial = self._dict |
| |
| @property |
| def diff(self): |
| d1 = self.__initial |
| d2 = self._dict |
| diffs = [(k, (v, d2[k])) for k, v in d1.items() if v != d2[k]] |
| return dict(diffs) |
| |
| @property |
| def has_changed(self): |
| return bool(self.diff) |
| |
| @property |
| def changed_fields(self): |
| return self.diff.keys() |
| |
| def get_field_diff(self, field_name): |
| return self.diff.get(field_name, None) |
| |
| def can_update(self, user): |
| if user.is_readonly: |
| return False |
| if user.is_admin: |
| return True |
| return False |
| |
| def delete(self, *args, **kwds): |
| # so we have something to give the observer |
| pk = self.pk |
| model_dict = model_to_dict(self) |
| for (k,v) in model_dict.items(): |
| # things like datetime are not JSON serializable |
| model_dict[k] = str(v) |
| |
| super(PlCoreBase, self).delete(*args, **kwds) |
| |
| # This is a no-op if observer_disabled is set |
| notify_observer(model=self, delete=True, pk=pk, model_dict=model_dict) |
| |
| def save(self, *args, **kwargs): |
| super(PlCoreBase, self).save(*args, **kwargs) |
| |
| # This is a no-op if observer_disabled is set |
| notify_observer() |
| |
| self.__initial = self._dict |
| |
| def save_by_user(self, user, *args, **kwds): |
| if self.can_update(user): |
| self.save(*args, **kwds) |
| |
| def delete_by_user(self, user, *args, **kwds): |
| if self.can_update(user): |
| self.delete(*args, **kwds) |
| |
| @property |
| def _dict(self): |
| return model_to_dict(self, fields=[field.name for field in |
| self._meta.fields]) |
| |
| |
| |