send error message to stderr instead of stdout

[plstackapi.git] / planetstack / core / models / plcorebase.py

diff --git a/planetstack/core/models/plcorebase.py b/planetstack/core/models/plcorebase.py
index 94c3d5a..ec79419 100644 (file)
--- a/planetstack/core/models/plcorebase.py
+++ b/planetstack/core/models/plcorebase.py
@@ -1,14 +1,30 @@
+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
-# This is a no-op if observer_disabled is set to 1 in the config file
-from observer import *
+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
 
 class PlCoreBase(models.Model):
 
-    created = models.DateTimeField(auto_now_add=True)
-    updated = models.DateTimeField(auto_now=True)
+    # default values for created and updated are only there to keep evolution
+    # from failing.
+
+    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)
 
     class Meta:
@@ -37,11 +53,25 @@ class PlCoreBase(models.Model):
     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=self.pk)
+        notify_observer(model=self, delete=True, pk=pk, model_dict=model_dict)
 
     def save(self, *args, **kwargs):
         super(PlCoreBase, self).save(*args, **kwargs)
@@ -51,6 +81,14 @@ class PlCoreBase(models.Model):
 
         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