JSON serialization of Google App Engine models

Question

I\'ve been searching for quite a while with no success. My project isn\'t using Django, is there a simple way to serialize App Engine models (google.appengine.ext.db.Model)

Answer 1

This is the simplest solution I found. It requires only 3 lines of codes.

Simply add a method to your model to return a dictionary:

class DictModel(db.Model):
    def to_dict(self):
       return dict([(p, unicode(getattr(self, p))) for p in self.properties()])

SimpleJSON now works properly:

class Photo(DictModel):
   filename = db.StringProperty()
   title = db.StringProperty()
   description = db.StringProperty(multiline=True)
   date_taken = db.DateTimeProperty()
   date_uploaded = db.DateTimeProperty(auto_now_add=True)
   album = db.ReferenceProperty(Album, collection_name='photo')

from django.utils import simplejson
from google.appengine.ext import webapp

class PhotoHandler(webapp.RequestHandler):
   def get(self):
      photos = Photo.all()
      self.response.out.write(simplejson.dumps([p.to_dict() for p in photos]))