save() で parent を指定できる djangoforms.ModelForm

gistfile1.py

import itertools
from google.appengine.ext.db.djangoforms import *
        
class ModelForm(djangoforms.ModelForm):
  def save(self, commit=True, parent=None, key_name=None, **kw):
    """Save this form's cleaned data into a model instance.

    Args:
      commit: optional bool, default True; if true, the model instance
        is also saved to the datastore.

    Returns:
      A model instance.  If a model instance was already associated
      with this form instance (either passed to the constructor with
      instance=...  or by a previous save() call), that same instance
      is updated and returned; if no instance was associated yet, one
      is created by this call.

    Raises:
      ValueError if the data couldn't be validated.
    """
    if not self.is_bound:
      raise ValueError('Cannot save an unbound form')
    opts = self._meta
    instance = self.instance
    if instance is None:
      fail_message = 'created'
    else:
      fail_message = 'updated'
    if self.errors:
      raise ValueError("The %s could not be %s because the data didn't "
                       'validate.' % (opts.model.kind(), fail_message))
    cleaned_data = self._cleaned_data()
    converted_data = {}
    propiter = itertools.chain(
      opts.model.properties().iteritems(),
      iter([('key_name', StringProperty(name='key_name'))])
      )
    for name, prop in propiter:
      value = cleaned_data.get(name)
      if value is not None:
        converted_data[name] = prop.make_value_from_form(value)
    try:
      if instance is None:
        kw.update(converted_data)
        instance = opts.model(parent=parent, key_name=key_name, **kw)
        self.instance = instance
      else:
        for name, value in converted_data.iteritems():
          if name == 'key_name':
            continue
          setattr(instance, name, value)
    except db.BadValueError, err:
      raise ValueError('The %s could not be %s (%s)' %
                       (opts.model.kind(), fail_message, err))
    if commit:
      instance.put()
    return instance