Question

This is ridicolously trivial but i’ve spent half an hour trying to solve it.

class SocialPost(model.Model):
  total_comments=model.IntegerProperty(default=0)

def create_reply_comment(self,content,author):
    ...
    logging.info(self)
    self.total_comments=self.total_comments+1
    self.put()

In the logfile, i can see how total_comments is 0 but in the admin console, it is 1. The other fields are correct, except for this one.

Probably there’s something wrong in that “default=0” but i can’t find what is wrong.

Edit: full code of my function

def create_reply_comment(self,content,author):
floodControl=memcache.get(“FloodControl-“+str(author.key))
if floodControl:
raise base.FloodControlException

    new_comment= SocialComment(parent=self.key)
    new_comment.author=author.key
    new_comment.content=content
    new_comment.put()

    logging.info(self)
    self.latest_comment_date=new_comment.creation_date
    self.latest_comment=new_comment.key
    self.total_comments=self.total_comments+1
    self.put()
    memcache.add("FloodControl-"+str(author.key), datetime.now(),time=SOCIAL_FLOOD_TIME)

Where i call the function:

if cmd == "create_reply_post":
           post=memcache.get("SocialPost-"+str(self.request.get('post')))
           if post is None:
              post=model.Key(urlsafe=self.request.get('post')).get()
              memcache.add("SocialPost-"+str(self.request.get('post')),post)
           node=node.get()
           if not node.get_subscription(user).can_reply:
               self.success()
               return


           post.create_reply_comment(feedparser._sanitizeHTML(self.request.get("content"),"UTF-8"),user)  

Answer 1

You’re calling memcache.add before you make your change to total_comments, so when you read it back from memcache on subsequent calls, you’re getting an out-of-date value from the cache. Your create_reply_comment needs to either delete or overwrite the "SocialPost-"+str(self.request.get('post') cache key.

[edit] Though your post title says you’re using NDB (model.Model though? Hmm.), so you could just skip the memcache bits entirely, and let NDB do it’s thing?