Question

Not sure what this means and why… I got the undefined method error when I try to go to http://localhost:3000/forums, and after I generate my first forum.

ActionView::TemplateError (undefined method `topics_path' for #<ActionView::Base:0x10319f2e0>) on line #25 of app/views/forums/index.html.erb:

The area of code the error refers to is: –

<!-- First column will be the forum name-->
<div class="forumname">
  <%= link_to forum.name, topics_path(forum) -%>
</div>

The relevant section of the route.rb file is: –

map.resources :forums do |forum|
  forum.resources :topics do |topic|
    topic.resources :posts
  end
end

Answer 1

You have topics nested under forums in your routes, so your url helper will be forum_topics_path(forum, topic). Notice you have to pass the forum and topic both to the helper.