Comments on Posts in Rails

Question

So I am trying to build a comments feature for my posts in a rails project but having troble figuring out the views and the controllers on being able to successfully make a comment on a post. The way I have it is that I have a link on each post in my news feed named comments that redirects you to a show page that shows a single post. on that page I would like to have a form just like my post form in the home page, but this one would be for comments on posts, any help figuring out the controllers, form for comments, and making them display under the post in the post show page would be much appreciated

here is the controller and view template for the Post controller

class PostsController < ApplicationController
    before_action :logged_in_user, only: [:show, :create, :destroy]
    before_action :correct_user, only: :destroy

  def show 
    @post = Post.find(params[:id])
  end 

    def create
        @post = current_user.posts.build(post_params)
        if @post.save
          redirect_to root_url
        else
          @feed_items = []
          render 'static_pages/home'
        end
    end 

    def destroy
        redirect_to request.referrer || root_url
    end 

    private 

     def post_params
      params.require(:post).permit(:content, :picture)
    end


    def correct_user
      @post = current_user.posts.find_by(id: params[:id])
      redirect_to root_url if @post.nil?
    end
end

the post show page

<% if logged_in? %>
  <div class="row">
    <aside class="col-md-4">
      <section class="user_info">
        <%= render 'shared/user_info' %>
      </section>
      </aside>
    <div class="col-md-8 posts">
      <h3>Comments</h3>
      <%= render 'posts/post_show' %>
    </div>
  </div>
<% end %>

My comments controller so far

class CommentsController < ApplicationController
    before_action :loged_in_user, only:[:create, :destroy]
    before_action :correct_user, only: :destroy

    def create
        @post = Post.find(params[:id])
        @comment = Comment.new(params[:comment])
        @comment.post = @post
        @comment.user = current_user
        if @comment.save
          redirect_to post
        else
           render 'post/show'
        end 
    end 

    def destroy 
    end 

    private 

    def comment_params 
        params.require(:comment).permit(:content, :picture)
    end 

    def correct_user
      @comment = current_user.comment.find_by(id: params[:id])
      render 'post/show' if @comment.nil?
    end
end

How my post partial is rendered would like to render comments the same way under the post in the post show page

<li id="post-<%= post.id %>">
  <%= link_to gravatar_for(post.user), post.user %>
  <span class="user"><%= link_to post.user.name, post.user %></span>
  <span class="content"><%= post.content %></span>
  <%= image_tag post.picture.url if post.picture? %>
  <span class="timestamp">
    Posted <%= time_ago_in_words(post.created_at) %> ago.
  <%= link_to "comments", post %>
  <% if current_user?(post.user) %>
      <%= link_to "delete", post, method: :delete, data: { confirm: "You sure?" } %>
    <% end %>
     </span>
</li>

my post model

class Post < ActiveRecord::Base
  belongs_to :user
  has_many :comments, dependent: :destroy
  default_scope -> { order(created_at: :desc) }
  mount_uploader :picture, PictureUploader
  validates :user_id, presence: true
  validates :content, presence: true, length: { maximum: 500 }
  validate  :picture_size


  private 

  def picture_size
     if picture.size > 10.megabytes
       errors.add(:picture, "should be less than 10MB")
     end
  end


end

and comments model

class Comment < ActiveRecord::Base
  belongs_to :user
  belongs_to :post
  default_scope -> { order(created_at )}
  validates :user_id , pressence: true 
  validates :post_id , pressence: true 
  validates :content, presence: true, length: { maximum: 500 }
  validate  :picture_size


  private 

  def picture_size
     if picture.size > 5.megabytes
       errors.add(:picture, "should be less than 5MB")
     end
  end
end

and this is my user model

class User < ActiveRecord::Base
  has_many :posts, dependent: :destroy
  has_many :comments, dependent: :destroy
    attr_accessor :remember_token, :activation_token, :reset_token 
    before_save :downcase_email
  before_create :create_activation_digest
    validates :name, presence: true, length: { maximum: 50 }
    VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
    validates :email, presence: true, length: { maximum: 250 },
                                      format: { with: VALID_EMAIL_REGEX },
                                      uniqueness: { case_sensitive: false}
    has_secure_password
    validates :password, presence: true, length: { minimum: 6 }, allow_nil: true 


  def User.digest(string)
     cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
                                                  BCrypt::Engine.cost
     BCrypt::Password.create(string, cost: cost)
  end

  # Returns a random token.
  def User.new_token
     SecureRandom.urlsafe_base64
  end

  def remember 
     self.remember_token = User.new_token
     update_attribute(:remember_digest, User.digest(remember_token))
  end

  def authenticated?(attribute, token)
    digest = send("#{attribute}_digest")
    return false if digest.nil?
    BCrypt::Password.new(digest).is_password?(token)
  end

  def forget
     update_attribute(:remember_digest, nil)
  end

  def activate
    update_attribute(:activated,    true)
    update_attribute(:activated_at, Time.zone.now)
  end

  # Sends activation email.
  def send_activation_email
    UserMailer.account_activation(self).deliver_now
  end

  # Sets the password reset attributes.
  def create_reset_digest
    self.reset_token = User.new_token
    update_attribute(:reset_digest,  User.digest(reset_token))
    update_attribute(:reset_sent_at, Time.zone.now)
  end

  # Sends password reset email.
  def send_password_reset_email
    UserMailer.password_reset(self).deliver_now
  end

  def password_reset_expired?
    reset_sent_at < 2.hours.ago
  end

  def feed
    Post.where("user_id = ?", id)
  end 

  private 

  def downcase_email 
    self.email = email.downcase
  end 

  def create_activation_digest 
    self.activation_token = User.new_token
    self.activation_digest = User.digest(activation_token)
  end 
end 

routes file

Rails.application.routes.draw do
  get 'password_resets/new'

  get 'password_resets/edit'

  root 'static_pages#home'
  get 'help' => 'static_pages#help'
  get 'about' => 'static_pages#about'
  get 'contact' => 'static_pages#contact'
  get 'signup' => 'users#new'
  get 'login' => 'sessions#new'
  post 'login' => 'sessions#create'
  delete 'logout' => 'sessions#destroy'
  resources :users 
  resources :account_activations, only: [:edit]
  resources :password_resets, only: [:new, :create, :edit, :update]
  resources :posts, only: [:show, :create, :destroy]
  resources :comments, only: [:show, :create, :destroy]
end

Answer 1

You can start from your route file. First of all, you need to define route for comments that belong to a post.

Here's how:

resources :posts do
  resources :comments
end

This way, you can edit a comment that belongs to a particular post like /posts/3/comments/2. This path will take you to the comment with id 2 that belongs to a post whose id is 3.

You also need to re-define all the methods in CommentsController. For example,

def update
  @post = Post.find(params[:id])
  @comment = Comment.find(params[:comment_id])
  ...
end

Well, that was just a sneak-peak of what you are supposed to do. It would be very lengthy indeed to show all the procedure here. Check out this to further have an idea of how it all fits.