I have a two-part somewhat noob question about form_for and nested resources. Let's say I'm writing a blog engine and I want to relate a comment to an article. I've defined a nested resource as follows:
map.resources :articles do |articles|
articles.resources :comments
end
The comment form is in the show.html.erb view for articles, underneath the article itself, for instance like this:
<%= render :partial => "articles/article" %>
<% form_for([ :article, @comment]) do |f| %>
<%= f.text_area :text %>
<%= submit_tag "Submit" %>
<% end %>
This gives an error, "Called id for nil, which would mistakenly etc." I've also tried
<% form_for @article, @comment do |f| %>
Which renders correctly but relates f.text_area to the article's 'text' field instead of the comment's, and presents the html for the article.text attribute in that text area. So I seem to have this wrong as well. What I want is a form whose 'submit' will call the create action on CommentsController, with an article_id in the params, for instance a post request to /articles/1/comments.
The second part to my question is, what's the best way to create the comment instance to begin with? I'm creating a @comment in the show action of the ArticlesController, so a comment object will be in scope for the form_for helper. Then in the create action of the CommentsController, I create new @comment using the params passed in from the form_for.
Thanks!