Question

I am using webapp2, ndb model.
I was trying to use django model forms with ndb model. Following is the relevant portions from my setup:

app.yaml:

libraries:
- name: webapp2
  version: "2.5.1"
- name: jinja2
  version: latest
- name: markupsafe                                                              
  version: latest
- name: django
  version: 1.3

Models.py:

class SubTask(ndb.Model):

    task = ndb.StructuredProperty(TaskList)
    description = ndb.TextProperty()
    start_time = ndb.DateTimeProperty()
    end_time = ndb.DateTimeProperty()

Forms.py:

from django.forms import ModelForm
from models import TaskList, TaskCategory, SubTask

class SubTaskForm(ModelForm):
    class Meta:
        model = SubTask

Handler:

class CreateSubTask(BaseHandler):
    def get(self):
        self.render_template('index.html', {'form':SubTaskForm})

app = webapp2.WSGIApplication([('/', IndexPage),
                               ('/subtask', CreateSubTask), ],
                              debug=True)

The error which i get is:
AttributeError: type object ‘SubTask’ has no attribute ‘_meta’

My Question: Is there a way i can use django model forms with ndb, or if i am making a mistake what is it?
If not django modelforms, does ndb model works fine with WTForms?

Attached below is the stacktrace:

ERROR    2012-06-23 03:25:58,770 wsgi.py:189] 
Traceback (most recent call last):
  File "/homeproject/expts/google_appengine/google/appengine/runtime/wsgi.py", line 187, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/homeproject/expts/google_appengine/google/appengine/runtime/wsgi.py", line 225, in _LoadHandler
    handler = __import__(path[0])
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1858, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1722, in FindAndLoadModule
    description)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1665, in LoadModuleRestricted
    description)
  File "/homeproject/expts/google_appengine/tdl/main.py", line 18, in <module>
    from views import IndexPage, CreateSubTask
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1858, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1722, in FindAndLoadModule
    description)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1665, in LoadModuleRestricted
    description)
  File "/homeproject/expts/google_appengine/tdl/views.py", line 4, in <module>
    from forms import SubTaskForm
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1858, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1722, in FindAndLoadModule
    description)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 676, in Decorate
    return func(self, *args, **kwargs)
  File "/homeproject/expts/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1665, in LoadModuleRestricted
    description)
  File "/homeproject/expts/google_appengine/tdl/forms.py", line 4, in <module>
    class SubTaskForm(ModelForm):
  File "/homeproject/expts/google_appengine/lib/django_1_3/django/forms/models.py", line 205, in __new__
    opts.exclude, opts.widgets, formfield_callback)
  File "/homeproject/expts/google_appengine/lib/django_1_3/django/forms/models.py", line 145, in fields_for_model
    opts = model._meta
AttributeError: type object 'SubTask' has no attribute '_meta'

Answer 1

Apart from the above comment, if you have not provided the settings in you main.py file, djangoforms won’t render. Apart from that you need to add a middleware:

'google.appengine.ext.ndb.NdbDjangoMiddleware'

Doing the above two will fix things.