Submitting data to two different tables with two different models (or how to modify multiple models from one form) (See related posts)

Taken from Norman Timmler's example on the ruby on rails mailing list.


Take two text fields for example:

# view
<%= form_tag :controller => :posts, :action => create %>
 <%= text_field("post", "title", "size" => 20) %>
 <%= text_field("user", "email", "size" => 20) %>
<%= end_form_tag %>

# posts_controller
class PostsController < ApplicationController
 def create
   @post = Post.create(params[:post])
   @user = User.create(params[:user])
   @post.users << @user
 end
end

In the controller the params hash has one key for every object (user,
post) in your form. As a values of this key you find a hash having a
key-value pair for every object attribute (title, email).

This way you can submit multiple objects via one form.