Question

I have the following models:

require 'books_projects.rb'

class Project < ActiveRecord::Base
  has_many :book_to_projects
  has_many :books, :through => :book_to_projects
end

require 'books_projects.rb'

class Book < ActiveRecord::Base
  has_many :book_to_projects
  has_many :projects, :through => :book_to_projects
end

books_projects.rb:

class BookToProject < ActiveRecord::Base
    set_table_name "books_projects"
    belongs_to :book
    belongs_to :project
end

In my projects controller, I am trying to do this:

@projects = Project.find(:all, :include => [:books])

My hope is to get a nested data structure back that looks something like:

projects: [
  {
    ..,
    books: [
        {
          ..
        },
        {
          ..
        }
    ]
  }
]

This doesn’t work. How can I achieve this?

Also, does the above model relationship call for the use of has_and_belongs_to_many in project and book instead of specifying the join table?

Thanks in advance!

Edit 1:
I don’t have a view. This acts like a REST service only. I am doing the following:

def index
  @projects = Project.find(:all, :include => [:books])

  respond_to do |format|
    format.xml  { render :xml => @projects }
    format.json { render :json => @projects}
  end
end

This does not produce the output that I’m looking for (mentioned above).

Answer 1

So turns out that the following works:

def index
  @projects = Project.find(:all)

  respond_to do |format|
    format.json { render :json => @projects.to_json(:include => [:books]) }
  end
end

Can someone tell me why this works and the one before didn’t?