AppEngine/Django: editing db.Key in the Admin app

Question

Or, to be precise, how do I properly present a form to edit a db.ListProperty of db.Keys on a model admin page, with app-engine-patch for Django?

I have a Category like this:

class Category(db.Model):
    title = db.CategoryProperty(required=True)

and a Post with this:

categories = db.ListProperty(db.Key)

Currently in the Django admin page the field is shown as a textbox containing the Python list object string, which is wrong and breaks saving:

[datastore_types.Key.from_path(u'blog_category', 3L, _app_id_namespace=u'xyz')]

So I've had to 'exclude' it in my ModelAdmin class. I've thought of writing a ModelForm that manually to wire up the Category db.Keys and present them as a Django multiselect widget, but I suspect there are easier ways to do it...

Answer 1

Having read through the App-engine-patch docs more thoroughly, seems that using ragendja.dbutils.KeyListProperty answers this problem, with the old Django multiselection list too. :)

New code:

categories = KeyListProperty(Category)