Model definition using couchDB


I am writing a RoR application which connects to a noSQL database

In the database, I have an author document. The author has a first_name
and a last_name. It also have inside another document: a book. The book
has a title and a year of publication.

  author {
    "first_name" : "abc",
    "last_name" : "def"
    "book" {
      "title" : "the jungle book",
      "year" : "1922"

I am trying to define the Author model file so I can access Author's
information as so related book information:

class Author < CouchRest::Model::Base

  property :first_name
  property :last_name
  property :book


However, when in the HTML file I try to access to the book author's
information, I get errors.

HTML example:
<td><%=h author.first_name %> <%=h author.last_name %> <%=h %></td>

The error I get is:
undefined method `title' for :book:Symbol

It's the first time I am developing a RoR application using a CouchDB
application, so I am pretty sure that the problem comes from the way I
am defining the Author's model file.

Can anyone help me about that?

Thank you