Polymorphic problems

rubyonrails-talk
1

Hi!

I have a problem related to polymorphic associations. Currently in my routes i define the following:

  map.resources :articles do |articles|     articles.resources :comments   end

  map.resources :posts do |posts|     posts.resources :comments   end

I have basically posts and articles models which relate to the polymorphic model comment. Routes are generated as I expect to, but the problem resides in the comments_controller, since in this controller I'm not able to figure out if I'm creating a comment for a post or for an article.

Is there a (possibly clean) way to solve this?

Thanks

2

Serafino Picozzi wrote:

Hi!

I have a problem related to polymorphic associations. Currently in my routes i define the following:

  map.resources :articles do |articles|     articles.resources :comments   end

  map.resources :posts do |posts|     posts.resources :comments   end

try this map.resources :articles ,:has_many=>:comments map.resources :posts ,:has_many=>:comments

3

Pokkai Dokkai wrote:

try this map.resources :articles ,:has_many=>:comments map.resources :posts ,:has_many=>:comments

This will only shorten the code in routes, but not solve my problem. Thanks for the tip in any case

4

You can check for the presence of params[:post_id] or params[:article_id] to discover the route that got triggered.

I generally use a before_filter:

class CommentsController < ApplicationController

before_filter :determine_parent before_filter :ensure_valid_comment

def determine_parent   @parent = Article.find_by_id(params[:article_id]) || Post.find(params[:post_id] end

def ensure_valid_comment   return unless params[:id]   raise ActiveRecord::RecordNotFound unless @parent.comments.find(params[:id]) end

end

This will first look for an article, and if that fails (returns nil), it will assume it's a post. Raises an exception of neither are found. The second filter helps ensure that someone didn't mess with the url.

Does this help?

Jeff purpleworkshops.com softiesonrails.com