Creating a form in the partials of a rendered collection - ruby-on-rails

Question

I am rendering a collection of Posts:
In posts_controller.rb:
def show
#posts = Post.where("user_id = ?", id)
end
In show.html.erb:
<ol>
<%= render #posts %>
</ol>
In _post.html.erb:
<%= form_for [post, #comment] do |f| %>
<%= f.text_area :content %>
<%= f.submit "Post" %>
<% end %>
The form_for in _post.html.erb is so someone can add a comment to any of the rendered posts. Comments are also of class Post. This means in the posts_controller I need something like #comment = Post.new(post_params) for the form in the partial. If I were only rendering a single Post this wouldn't be a problem. However, I am rendering a collection of Posts, each of which needs a #comment instance variable passed to it. How do I create a #comment instance variable in the posts_controller for each post? And how do I pass these #comments to the partials? And what's the correct code in form_for in the partial?

Answer 1

You should explicitly build the comment for each post like below,
def show
#posts = Post.where("user_id = ?", id)
#posts.each{|post| post.comments.build}
end
and use the same in form,
<%= form_for [post, post.comments.last] do |f| %>
<%= f.text_area :content %>
<%= f.submit "Post" %>
<% end %>
This will build the comment for every post while rendering the page, which can be accessed by post.comments.last. Comment won't exist in database until the comment form associated with post is submitted.
Note: Need to modify post.comments.last if default scope is changed http://apidock.com/rails/ActiveRecord/Base/default_scope/class

Answer 2

You should specify that each post contains a/many comment and build those
class Post
attribute :comments, type:Comment, typecaster: Comment, default: []
end
Class Comment
end
Now in the form you can simply render using
<%=#post.comments%>
PS : Do not keep comment as a post type if you want to avoid rendering comments for comments and so on.(You can use the same type as well)