Polymorphic problems

Rails
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 P. 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 D. 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

On Oct 14, 4:40 am, Serafino P. <rails-mailing-l…@andreas-
s.net> wrote:

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?

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