Saving wiki versions in Google App Engine / Django - Modifying this existing code

Question

In the past, I created the Django wiki, and it was pretty simple to make a page table for the current entries in the wiki, and then save the old versions in the Revision table.

Most recently, I decided to create a website in the Google App Engine, and I used the wiki code that another programmer wrote. Since he created his page model in a complicated way (at least with my help) using Entities, I'm not sure how to create a Revision table and integrate it with his page model.

Here is the relevant code. Can someone help me write a Revision model and integrate saving changes using the Save method of the page model?

class Page(object):

  def __init__(self, name, entity=None):
    self.name = name
    self.entity = entity
    if entity:
      self.content = entity['content']
      if entity.has_key('user'):
        self.user = entity['user']
      else:
        self.user = None
      self.created = entity['created']
      self.modified = entity['modified']
    else:
      # New pages should start out with a simple title to get the user going
      now = datetime.datetime.now()
      self.content = '<h1>' + cgi.escape(name) + '</h1>'
      self.user = None
      self.created = now
      self.modified = now

  def save(self):
    """Creates or edits this page in the datastore."""
    now = datetime.datetime.now()
    if self.entity:
      entity = self.entity
    else:
      entity = datastore.Entity('Page')
      entity['name'] = self.name
      entity['created'] = now
    entity['content'] = datastore_types.Text(self.content)
    entity['modified'] = now

    if users.GetCurrentUser():
      entity['user'] = users.GetCurrentUser()
    elif entity.has_key('user'):
      del entity['user']

    datastore.Put(entity)

, : http://code.google.com/p/google-app-engine-samples/downloads/list

GAE Django, , , . , . :

class Article(db.Model):
  author = db.UserProperty()
  title = db.StringProperty(required=True)
  text = db.TextProperty(required=True)
  tags = db.StringProperty(required=True)
  date_created = db.DateProperty(auto_now_add=True)

Answer 1

( Page):

class Revision (db.Model):
  name = db.StringProperty(required=True)
  created = db.DateTimeProperty(required=True)
  modified = db.DateTimeProperty(auto_now_add=True)
  content = db.TextProperty(required=True)
  user = db.UserProperty()

Save() , , :

r = Revision(name = self.name,
             content = self.content,
             created = self.created,
             modified = self.modified,
             user = self.user)
r.put()

wiki, , GET, , . , :

page = models.Page.load(title)

if request.GET.get('rev'):
  query = db.Query(models.Revision)
  query.filter('name =', title).order('created')
  rev = request.GET.get('rev')
  rev_page = query.fetch(1, int(rev))
  page.content = rev_page.content

Answer 2

- , . , , , .

, App Engine, Django. Django App Engine.