Polymorphic Comments with Ancestry Problems

问题

I am trying to roll together two Railscasts: http://railscasts.com/episodes/262-trees-with-ancestry and http://railscasts.com/episodes/154-polymorphic-association on my app.

My Models:

class Location < ActiveRecord::Base
  has_many :comments, :as => :commentable, :dependent => :destroy
end

class Comment < ActiveRecord::Base
  belongs_to :commentable, :polymorphic => true
end

My Controllers:

class LocationsController < ApplicationController
      def show
        @location = Location.find(params[:id])
        @comments = @location.comments.arrange(:order => :created_at)

        respond_to do |format|
          format.html # show.html.erb
          format.json { render json: @location }
        end
      end
end

class CommentsController < InheritedResources::Base

  def index
    @commentable = find_commentable
    @comments = @commentable.comments.where(:company_id => session[:company_id])
  end

  def create
    @commentable = find_commentable
    @comment = @commentable.comments.build(params[:comment])
    @comment.user_id = session[:user_id]
    @comment.company_id = session[:company_id]
    if @comment.save
      flash[:notice] = "Successfully created comment."
      redirect_to :id => nil
    else
      render :action => 'new'
    end
  end

  private

  def find_commentable
    params.each do |name, value|
      if name =~ /(.+)_id$/
        return $1.classify.constantize.find(value)
      end
    end
    nil
  end

end

In my locations show view I have this code:

<%= render @comments %>
<%= render "comments/form" %>

Which outputs properly. I have a _comment.html.erb file that renders each comment etc. and a _form.html.erb file that creates the form for a new comment.

The problem I have is that when I try <%= nested_comments @comments %> I get undefined method 'arrange'.

I did some Googling and the common solution to this was to add subtree before the arrange but that throws and undefined error also. I am guessing the polymorphic association is the problem here but I am at a loss as to how to fix it.

回答1:

Dumb mistake... forgot to add the ancestry gem and required migration which I thought I had already done. The last place I checked was my model where I eventually discovered my error.

来源：https://stackoverflow.com/questions/10369896/polymorphic-comments-with-ancestry-problems

标签

ruby-on-rails-3

polymorphic-associations

ancestry