Model vs schemaless database

[László Tenki]

Hi group members,

I asked a question on stackoverflow a day ago, there's still no answer. So I try it here too:

http://stackoverflow.com/questions/19294120/mongomodel-gem-vs-the-schemaless-databas

I'm using the MongoModel gem in a Ruby on Rails project and it works fine. Works fine as long as you strictly follow the structure defined in your models, so basically using MongoDB as a database with schema. But one of the advantages of MongoDB, well, from a certain perspective, is that it is a schemaless database. And I would like to make use of it, add random fields to documents, just as you can in the mongo shell.

How to do that? Is there a way?