ruby - Rails polymorphic comments ajax - 500 (Internal Server Error) -

i used tutorial making polymorphic comments

https://gorails.com/episodes/comments-with-polymorphic-associations

it works fine when set remote true comments form got 505 error(the new comment not appended list) when trying add new comment.

but when reload page new comment appears in list.

what can wrong here?

i got files in views/comments folder:

create.js

<% unless @comment.errors.any? %> $("ul.comments").append('<%= j render "comments/comment" %>') $("#new_comment")[0].reset(); <% end %> 

_form.html.erb

<%= simple_form_for([commentable, comment.new], remote: true) |f| %>   <%= f.input :body, label: false %>   <%= f.button :submit, "submit" %> <% end %> 

comments_controller.rb

  def create     @comment = @commentable.comments.new(comment_params)     @comment.user = current_user     @comment.save     respond_to |format|       format.html { redirect_to @commentable, notice: "your comment added."}       format.js     end   end 

_comment.html.erb

  <li class="comment">     <b><%= comment.user.try(:username) %>:</b>     <%= comment.body%>   </li> 

console

up

i got routes post

  resources :posts      resources :comments, module: :posts   end 

+ controllers/posts/comments_controller

class posts::commentscontroller < commentscontroller   before_action :set_commentable    private   def set_commentable     @commentable = post.friendly.find(params[:post_id])   end end 

the folder structure looks same here https://github.com/excid3/gorails-episode-36/tree/master/app/controllers

the response tab shows this

undefined local variable or method `comment' #<#<class:0x007f993d3c5450>:0x007f99450a6190> trace of template inclusion: app/views/comments/create.js.erb 

and when replace

<%= j render @comment %> text appends list on submit

ok problem _comment.html erb

updated create.js instance variable comment , works now.

<% unless @comment.errors.any? %> $("ul.comments").append('<%= j render partial: "comments/comment", locals:{comment: @comment} %>') $("#new_comment")[0].reset(); <% end %>