import os
+import sys
from django.db import models
from django.forms.models import model_to_dict
-from observer.event_manager import EventSender
-
-
-class PlCoreBase(models.Model):
-
- created = models.DateTimeField(auto_now_add=True)
- updated = models.DateTimeField(auto_now=True)
- enacted = models.DateTimeField(null=True, default=None)
-
- class Meta:
- 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 delete(self, *args, **kwds):
- super(PlCoreBase, self).delete(*args, **kwds)
-
- try:
- EventSender().fire({'delete_flag':True,'model':self.__name__})
- except:
- # Investigate later.
- pass
-
-
- def save(self, *args, **kwargs):
- super(PlCoreBase, self).save(*args, **kwargs)
-
- # Tell the observer that the source database has been updated
- EventSender().fire()
-
- self.__initial = self._dict
+from django.core.urlresolvers import reverse
+from django.forms.models import model_to_dict
+from django.utils import timezone
+from django.core.exceptions import PermissionDenied
+import model_policy
+
+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 PlCoreBaseDeletionManager(models.Manager):
+ def get_queryset(self):
+ parent=super(PlCoreBaseDeletionManager, self)
+ if hasattr(parent, "get_queryset"):
+ return parent.get_queryset().filter(deleted=True)
+ else:
+ return parent.get_query_set().filter(deleted=True)
+
+ # deprecated in django 1.7 in favor of get_queryset().
+ def get_query_set(self):
+ return self.get_queryset()
+
+# This manager will be inherited by all subclasses because
+# the core model is abstract.
+class PlCoreBaseManager(models.Manager):
+ def get_queryset(self):
+ parent=super(PlCoreBaseManager, self)
+ if hasattr(parent, "get_queryset"):
+ return parent.get_queryset().filter(deleted=False)
+ else:
+ return parent.get_query_set().filter(deleted=False)
+
+ # deprecated in django 1.7 in favor of get_queryset().
+ def get_query_set(self):
+ return self.get_queryset()
+
+class DiffModelMixIn:
+ # Provides useful methods for computing which objects in a model have
+ # changed. Make sure to do self._initial = self._dict in the __init__
+ # method.
+
+ # This is broken out of PlCoreBase into a Mixin so the User model can
+ # also make use of it.
+
+ @property
+ def _dict(self):
+ return model_to_dict(self, fields=[field.name for field in
+ self._meta.fields])
+
+ @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 has_field_changed(self, field_name):
+ return field_name in self.diff.keys()
+
+ def get_field_diff(self, field_name):
+ return self.diff.get(field_name, None)
+
+class PlCoreBase(models.Model, DiffModelMixIn):
+ objects = PlCoreBaseManager()
+ deleted_objects = PlCoreBaseDeletionManager()
+
+ # default values for created and updated are only there to keep evolution
+ # from failing.
+ created = models.DateTimeField(auto_now_add=True, default=timezone.now)
+ updated = models.DateTimeField(auto_now=True, default=timezone.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 # for DiffModelMixIn
+ self.silent = False
+
+ 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
+ purge = kwds.get('purge',False)
+ if purge:
+ del kwds['purge']
+ silent = kwds.get('silent',False)
+ if silent:
+ del kwds['silent']
+ try:
+ purge = purge or observer_disabled
+ except NameError:
+ pass
+
+ if (purge):
+ super(PlCoreBase, self).delete(*args, **kwds)
+ else:
+ self.deleted = True
+ self.enacted=None
+ self.save(update_fields=['enacted','deleted'], silent=silent)
+
+ def save(self, *args, **kwargs):
+ # let the user specify silence as either a kwarg or an instance varible
+ silent = self.silent
+ if "silent" in kwargs:
+ silent=silent or kwargs.pop("silent")
+
+ super(PlCoreBase, self).save(*args, **kwargs)
+
+ # This is a no-op if observer_disabled is set
+ if not silent:
+ notify_observer()
+
+ self._initial = self._dict
+
+ def save_by_user(self, user, *args, **kwds):
+ if not self.can_update(user):
+ if getattr(self, "_cant_update_fieldName", None) is not None:
+ raise PermissionDenied("You do not have permission to update field %s on object %s" % (self._cant_update_fieldName, self.__class__.__name__))
+ else:
+ raise PermissionDenied("You do not have permission to update %s objects" % self.__class__.__name__)
+
+ self.save(*args, **kwds)
+
+ def delete_by_user(self, user, *args, **kwds):
+ if not self.can_update(user):
+ raise PermissionDenied("You do not have permission to delete %s objects" % self.__class__.__name__)
+ self.delete(*args, **kwds)
+
+ @classmethod
+ def select_by_user(cls, user):
+ # This should be overridden by descendant classes that want to perform
+ # filtering of visible objects by user.
+ return cls.objects.all()
- @property
- def _dict(self):
- return model_to_dict(self, fields=[field.name for field in
- self._meta.fields])