Question

I am a newbie RoR developer. I am stuck in one problem. I am trying to make a application with users who can create a topic and others can post their comments under the topic..The topics are created by user and listed on the main page as a list. I am almost done with the topics. But when i click them to see the posts, I get Couldn’t find Topic without an ID error.

I guess that my mistake is topics has two indexes id and user_id.
here is my Topic model :

class Topic < ActiveRecord::Base
  attr_accessible :content, :title
  belongs_to    :user
  has_many      :posts
  validates :title, presence: true, length: { maximum: 140 }
  validates :content, presence: true
  validates :user_id, presence: true
  default_scope order: 'topics.created_at DESC'
end

And my post model

class Posts < ActiveRecord::Base
  attr_accessible :content 
  belongs_to :topic
  belongs_to :user
  validates :user_id, presence: true
  validates :content, presence: true
  default_scope order: 'posts.created_at DESC'
end

this is my topics_controller.rb:

class TopicsController < ApplicationController
  before_filter :signed_in_user, only: [:create, :destroy]
  before_filter :correct_user, only: :destroy

    def show
        @topic = Topic.find(params[:id])
        @posts = @topic.posts.paginate :page => params[:page], :per_page => 20
    end
       .
       ..vs

and this is my config/routes.rb

MyPedia::Application.routes.draw do
    resources :users
    resources :sessions, only: [:new, :create, :destroy]
    resources :topics, only: [:show, :create, :destroy]
    resources :posts
    root to: 'static_pages#home'


    match '/topicin',   to: 'topics#show'
    match '/signup',  to: 'users#new'
  match '/signin',  to: 'sessions#new'
  match '/signout', to: 'sessions#destroy', via: :delete

    match '/help',    to: 'static_pages#help'
    match '/about',   to: 'static_pages#about'
    match '/contact', to: 'static_pages#contact'

my topics show.html.erb

<% title @topic.title %>  
<div class ="center">
<h3><%= @topic.title %></h3>  

<% if @posts? %>  


  <% for post in @posts do %>  
    <p><strong><%= post.content %>  
  <% end %>  
<% end %>  
</div> 

I try to find a way to solve this problem.
thanks for helps

Answer 1

Try using GET /topic/1, that will help. The way you have set up the matched route is wrong and probably redundant. You can have a look here for more info: http://guides.rubyonrails.org/routing.html