Models in Ruby Rhodes basic questions

I'm fresh to Rhodes and don't have any experience with RoR.

I created a new model in my application: rhogen model CoffeeKind name,description,vendor,picture

I would like to:

1. add a new property ("sizes")

2. reference another model from within this one ("vendor" referencing CoffeeVendor)

3. import various coffee kinds from json

I've got experience with Python / Django / Google App Engine, but not with Ruby / RoR.

How do I perform above tasks? Or where can I look for help? I tried googling and c开发者_如何转开发hecking out documentation but found nothing :/

Help! :)

(I'm adding ruby on rails tag to this because I heard that it's similar to Rhodes)

Here's what I posted on the group:

The app generator ("rhogen" or "rhodes" command) is a "once only" thing, as it is with Rails and Django scaffolding. After initial generation if you want to add new attributes,just edit your forms to have that new attributes. It is property bag model so there is no need to create a database column or explicit modify the model