How do I use Simple_Form with nested resources?

I have 3 models: FamilyTree, Node, comment.

Every entry in FamilyTree is a Node. A node could be a comment.

The models look like this:

FamilyTree.rb

# == Schema Information
#
# Table name: family_trees
#
#  id         :integer          not null, primary key
#  name       :string(255)
#  user_id    :integer
#  created_at :datetime
#  updated_at :datetime
#

class FamilyTree < ActiveRecord::Base
  attr_accessible :name
  belongs_to :user
  has_many :memberships, dependent: :destroy
  has_many :members, through: :memberships, source: :user, dependent: :destroy
  has_many :nodes, dependent: :destroy
end

      

        
        
        
      

    

Node.rb

# == Schema Information
#
# Table name: nodes
#
#  id             :integer          not null, primary key
#  name           :string(255)
#  family_tree_id :integer
#  user_id        :integer
#  media_id       :integer
#  media_type     :string(255)
#  created_at     :datetime
#  updated_at     :datetime
#  circa          :datetime
#  is_comment     :boolean
#

class Node < ActiveRecord::Base
  belongs_to :family_tree
  belongs_to :user
  belongs_to :media, polymorphic: true, dependent: :destroy
  has_many :comments, dependent: :destroy
  has_many :node_comments, dependent: :destroy    
end

      

        
        
        
      

    

Comment.rb

# == Schema Information
#
# Table name: comments
#
#  id         :integer          not null, primary key
#  user_id    :integer
#  message    :text
#  node_id    :integer
#  created_at :datetime
#  updated_at :datetime
#

class Comment < ActiveRecord::Base
  validates :message, presence: true    
  belongs_to :user
  belongs_to :node    
end

      

        
        
        
      

    

routes.rb

  resources :family_trees do
    resources :nodes do
      resources :comments
    end
  end

      

        
        
        
      

    

How do I use Simple_Form to edit a comment? What does it look like?

I've tried this:

<%= simple_form_for [@family_tree, @node, @comment] do |f| %>
  <%= f.error_notification %>

  <div class="form-inputs">
    <%= f.association :user %>
    <%= f.input :message %>
    <%= f.association :node %>
  </div>

  <div class="form-actions">
    <%= f.button :submit %>
  </div>
<% end %>

      

        
        
        
      

    

But it gave me this error. On line 1 of this partial:

NoMethodError at /family_trees/1/nodes/4/comments/3/edit
undefined method `family_tree_comment_path' for #<#<Class:0x007f87356c5110>:0x007f8733d338a0>