planetstack/model_policy.py

   1 from django.db.models.signals import post_save
   2 from django.dispatch import receiver
   3 import pdb
   4 from core.models import *
   5 from dependency_walker import *
   6 import model_policies
   7 from util.logger import logger
   8
   9
  10 modelPolicyEnabled = True
  11
  12 def EnableModelPolicy(x):
  13     global modelPolicyEnabled
  14     modelPolicyEnabled = x
  15
  16 def update_dep(d, o):
  17         try:
  18                 if (d.updated < o.updated):
  19                         d.save(update_fields=['updated'])
  20         except AttributeError,e:
  21                 raise e
  22
  23 def delete_if_inactive(d, o):
  24         #print "Deleting %s (%s)"%(d,d.__class__.__name__)
  25         d.delete()
  26         return
  27
  28 def execute_model_policy(policy_name, instance, update_fields_empty, deleted):
  29         if (update_fields_empty):
  30                 # Automatic dirtying
  31                 #walk_inv_deps(update_dep, instance)
  32
  33                 try:
  34                         policy_handler = getattr(model_policies, policy_name, None)
  35                         logger.error("POLICY HANDLER: %s %s" % (policy_name, policy_handler))
  36                         if policy_handler is not None:
  37                                 policy_handler.handle(instance)
  38                 except:
  39                         logger.log_exc("Model Policy Error:")
  40                         print "Policy Exceution Error"
  41         elif deleted:
  42                 walk_inv_deps(delete_if_inactive, instance)
  43
  44
  45 @receiver(post_save)
  46 def post_save_handler(sender, instance, **kwargs):
  47         if not modelPolicyEnabled:
  48             return
  49
  50         sender_name = sender.__name__
  51         policy_name = 'model_policy_%s'%sender_name
  52         if (not kwargs['update_fields']):
  53                 noargs = True
  54                 deleted = False
  55         else:
  56                 noargs = False
  57                 deleted = True
  58
  59         execute_model_policy(policy_name, instance, noargs, deleted)
  60
  61