How to link post to topic? - ruby-on-rails

Question

I made a latest posts box in my app at the root. In this box I have post which belongs to topic. Maybe its a stupid question but how can I redirect click on post to the topic where it belongs?
This redirects me to localhost:3000/topics, how to add topic_id's to this path?
This is how I get the latest posts:
controller:
class ApplicationController < ActionController::Base
# Prevent CSRF attacks by raising an exception.
# For APIs, you may want to use :null_session instead.
protect_from_forgery with: :exception
before_filter :configure_permitted_parameters, if: :devise_controller?
helper_method :latest_posts
def latest_posts
#posts ||= Post.all.order("created_at desc").limit(3)
end
end
index:
<% latest_posts.each do |posts| %>
<div class="bs-callout bs-callout-warning">
<p><%= link_to post.content.html_safe, topic_path(post.topic) %></p>
</div>
<% end %>
routes.rb:
devise_for :users
get 'categories' => 'categories#index'
resources :topics
resources :posts
resources :users
Routes:
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /users/sign_out(.:format) devise/sessions#destroy
user_password POST /users/password(.:format) devise/passwords#create
new_user_password GET /users/password/new(.:format) devise/passwords#new
edit_user_password GET /users/password/edit(.:format) devise/passwords#edit
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) devise/registrations#cancel
user_registration POST /users(.:format) devise/registrations#create
new_user_registration GET /users/sign_up(.:format) devise/registrations#new
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
PATCH /users(.:format) devise/registrations#update
PUT /users(.:format) devise/registrations#update
DELETE /users(.:format) devise/registrations#destroy
categories GET /categories(.:format) categories#index
topics GET /topics(.:format) topics#index
POST /topics(.:format) topics#create
new_topic GET /topics/new(.:format) topics#new
edit_topic GET /topics/:id/edit(.:format) topics#edit
topic GET /topics/:id(.:format) topics#show
PATCH /topics/:id(.:format) topics#update
PUT /topics/:id(.:format) topics#update
DELETE /topics/:id(.:format) topics#destroy
posts GET /posts(.:format) posts#index
POST /posts(.:format) posts#create
new_post GET /posts/new(.:format) posts#new
edit_post GET /posts/:id/edit(.:format) posts#edit
post GET /posts/:id(.:format) posts#show
PATCH /posts/:id(.:format) posts#update
PUT /posts/:id(.:format) posts#update
DELETE /posts/:id(.:format) posts#destroy
users GET /users(.:format) users#index
POST /users(.:format) users#create
new_user GET /users/new(.:format) users#new
edit_user GET /users/:id/edit(.:format) users#edit
user GET /users/:id(.:format) users#show
PATCH /users/:id(.:format) users#update
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
root GET / categories#index

Answer 1

You're going to want to first iterate through the posts, then link to the topic base on the single instance of post.
<h5>Here are all of my posts</h5>
<% #posts.each do |post| %>
<%= link_to post.content.html_safe, topic_path(post.topic) %>
<% end %>
Here is a solid Rails guides post on ActionView and rendering. It's definitely worth the read.

Answer 2

Assuming you have defined the show route in your config/routes.rb, you can use the topic_path helper.
<%= link_to posts.content.html_safe, topic_path(topic) %>
Where topic is the instance which you want to redirect to.