disable observer if it fails to import

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

diff --git a/planetstack/core/models/plcorebase.py b/planetstack/core/models/plcorebase.py
index 52aa0f7..7251a81 100644 (file)
--- a/planetstack/core/models/plcorebase.py
+++ b/planetstack/core/models/plcorebase.py
@@ -1,14 +1,93 @@
 import os
 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 "import of observer failed! printing traceback and disabling observer:"
+    import traceback
+    traceback.print_exc()
+
+    # guard against something failing
+    def notify_observer():
+        pass
 
 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 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])
+