Add Comment to User and Post models (Ruby on Rails)

Question

I\'m new to Rails. I\'m building my first app - simple blog. I have User and Post models, where each user can write many posts. Now I want to add Comment model, where each post

Answer 1

Associations

To give you a definition of what's happening here, you have to remember whenever you create a record, you are basically populating a database. Your associations are defined with foreign_keys

When you ask how to "add comments to User and Post model" - the bottom line is you don't; you add a comment to the Comment model, and can associate it with a User and Post:

#app/models/comment.rb
Class Comment < ActiveRecord::Base
    belongs_to :user
    belongs_to :post
end

This prompts Rails to look for user_id and post_id in the Comment model by default.

This means if you wanted to create a comment directly, you can associate it to either of these associations by simply populating the foreign_keys as you wish (or use Rails objects to populate them)

So when you want to save a comment, you can do this:

#app/controllers/comments_controller.rb
Class CommentsController < ApplicationController
   def create
       @comment = Comment.new(comment_params)
   end

   private

   def comment_params
        params.require(:comment).permit(:user_id, :post_id, :etc)
   end
end

Conversely, you can handle it by using standard Rails objects (as the accepted answer has specified)