3 from django.db import models
4 from django.forms.models import model_to_dict
5 from django.core.urlresolvers import reverse
6 from django.forms.models import model_to_dict
7 from django.utils import timezone
8 from django.core.exceptions import PermissionDenied
12 # This is a no-op if observer_disabled is set to 1 in the config file
13 from observer import *
15 print >> sys.stderr, "import of observer failed! printing traceback and disabling observer:"
19 # guard against something failing
20 def notify_observer(*args, **kwargs):
23 # This manager will be inherited by all subclasses because
24 # the core model is abstract.
25 class PlCoreBaseDeletionManager(models.Manager):
26 def get_queryset(self):
27 parent=super(PlCoreBaseDeletionManager, self)
28 if hasattr(parent, "get_queryset"):
29 return parent.get_queryset().filter(deleted=True)
31 return parent.get_query_set().filter(deleted=True)
33 # deprecated in django 1.7 in favor of get_queryset().
34 def get_query_set(self):
35 return self.get_queryset()
37 # This manager will be inherited by all subclasses because
38 # the core model is abstract.
39 class PlCoreBaseManager(models.Manager):
40 def get_queryset(self):
41 parent=super(PlCoreBaseManager, self)
42 if hasattr(parent, "get_queryset"):
43 return parent.get_queryset().filter(deleted=False)
45 return parent.get_query_set().filter(deleted=False)
47 # deprecated in django 1.7 in favor of get_queryset().
48 def get_query_set(self):
49 return self.get_queryset()
52 # Provides useful methods for computing which objects in a model have
53 # changed. Make sure to do self._initial = self._dict in the __init__
56 # This is broken out of PlCoreBase into a Mixin so the User model can
57 # also make use of it.
61 return model_to_dict(self, fields=[field.name for field in
68 diffs = [(k, (v, d2[k])) for k, v in d1.items() if v != d2[k]]
72 def has_changed(self):
73 return bool(self.diff)
76 def changed_fields(self):
77 return self.diff.keys()
79 def has_field_changed(self, field_name):
80 return field_name in self.diff.keys()
82 def get_field_diff(self, field_name):
83 return self.diff.get(field_name, None)
85 class PlCoreBase(models.Model, DiffModelMixIn):
86 objects = PlCoreBaseManager()
87 deleted_objects = PlCoreBaseDeletionManager()
89 # default values for created and updated are only there to keep evolution
91 created = models.DateTimeField(auto_now_add=True, default=timezone.now)
92 updated = models.DateTimeField(auto_now=True, default=timezone.now)
93 enacted = models.DateTimeField(null=True, default=None)
94 backend_status = models.CharField(max_length=140,
95 default="Provisioning in progress")
96 deleted = models.BooleanField(default=False)
99 # Changing abstract to False would require the managers of subclasses of
100 # PlCoreBase to be customized individually.
104 def __init__(self, *args, **kwargs):
105 super(PlCoreBase, self).__init__(*args, **kwargs)
106 self._initial = self._dict # for DiffModelMixIn
109 def can_update(self, user):
117 def delete(self, *args, **kwds):
118 # so we have something to give the observer
119 purge = kwds.get('purge',False)
122 silent = kwds.get('silent',False)
126 purge = purge or observer_disabled
131 super(PlCoreBase, self).delete(*args, **kwds)
135 self.save(update_fields=['enacted','deleted'], silent=silent)
137 def save(self, *args, **kwargs):
138 # let the user specify silence as either a kwarg or an instance varible
140 if "silent" in kwargs:
141 silent=silent or kwargs.pop("silent")
143 super(PlCoreBase, self).save(*args, **kwargs)
145 # This is a no-op if observer_disabled is set
149 self._initial = self._dict
151 def save_by_user(self, user, *args, **kwds):
152 if not self.can_update(user):
153 if getattr(self, "_cant_update_fieldName", None) is not None:
154 raise PermissionDenied("You do not have permission to update field %s on object %s" % (self._cant_update_fieldName, self.__class__.__name__))
156 raise PermissionDenied("You do not have permission to update %s objects" % self.__class__.__name__)
158 self.save(*args, **kwds)
160 def delete_by_user(self, user, *args, **kwds):
161 if not self.can_update(user):
162 raise PermissionDenied("You do not have permission to delete %s objects" % self.__class__.__name__)
163 self.delete(*args, **kwds)
166 def select_by_user(cls, user):
167 # This should be overridden by descendant classes that want to perform
168 # filtering of visible objects by user.
169 return cls.objects.all()