resource loading patterns

first.rb

class PostsController
  before_filter :load_user
  before_filter :load_post

  def show
    respond_with(@post)
  end

  def load_user
    @user = User.find(params[:user_id])
  end

  def load_post
    @post = @user.posts.find(params[:id])
  end
end

second.rb

class PostsController
  def show
    respond_with(post)
  end

  def user
    @user ||= User.find(params[:user_id])
  end

  def post
    @post ||= user.posts.find(params[:id])
  end
end