How to fill a ListProperty?

[pgio]

I'm making progress with AppengineJS. I've got a model fully defined,
but I'm having problems with ListProperties. What's the proper method
to fill them? .push() is what I've been trying, but it doesn't work on
a null '' result. Is there something in particular I should be storing
in the ListProperty when the object that owns it is created, to avoid
this problem? Or am I simply using the wrong method?

Pete

[George Moschovitis]

try:

 var Message = exports.Message = db.Model('Message',{

  ..

  tags: new db.ListProperty()

  ...

} 

var m = new Message({

  ..

  tags: ["hello", "world"]

  ..

});

regards,

-g.

--
http://www.gmosx.com/blog
http://www.appenginejs.org

[pgio]

It seems that I must pass in a dummy value to the list when it is
created, like

var m = new Message({

...
comments = ["none"]
...
});

then .push() works if you're pushing a string. But the property is
defined as

var Message = exports.Message = db.Model('Message',{

...
comments: new db.ListProperty(Comment)
...
});

and when I try to pass in a Comment object I get:

JavaException: java.lang.IllegalArgumentException: comments:
org.mozilla.javascript.NativeObject is not a supported property type.
(google/appengine/ext/db/model.js#245)

With my CustomUser object, which has a .friendlist of CustomUser
objects, I had to pass in the .userid for the CustomUser, and the
userids are stored in the list, since passing a CustomUser object
produced the same Java exception. Perhaps I should create a similar
property for my Comment object?

Pete

[pgio]

Just found out that the empty list [""] works for an initial value as
well; I thought it would evaluate as equal to null but apparently not.
Guess it makes sense.

Pete

[Frederick Polgardy]

That's not the empty list. That's a list of one element: the empty string. Why wouldn't [] work?

--
Science answers questions; philosophy questions answers.

[pgio]

It was returning an error -- something like "can't call method push of
object null."