Now that we have posts fully set up in our application, it's time to scaffold the comments resource, allowing users to add comments under any post.

Let's return to our application and run another Rails generator. This time, we will scaffold a Comment resource.

Generating the Comments Resource

A comment has three key attributes:

• It belongs to a post.
• It belongs to a user.
• It has a body (text) that is required.

Let’s generate this resource by running the following command:

bin/rails generate scaffold Comment post:belongs_to user:belongs_to 'body:text!'

As always, this command generates:

• A migration to create the database table
• A model with the necessary relationships
• Resourceful routes
• A controller with RESTful actions
• View templates
• Tests for validation and functionality

Setting Up the Comments Model

Let’s inspect the generated migration. This migration ensures:

• Every comment belongs to a post and a user (with foreign keys).
• The body field is required (null: false).

Let’s run our migrations to apply these changes.

Now that the comments table is created, we can commit our changes.

Defining Associations in Models

Next, we need to define the relationships in our models.

Comment Model (Generated by Rails)

class Comment < ApplicationRecord
  belongs_to :post
  belongs_to :user
end

We also need to update the Post model to establish its relationship with comments:

class Post < ApplicationRecord
  belongs_to :user
  has_many :comments, dependent: :destroy
end

Adding dependent: :destroy ensures that when a post is deleted, all its associated comments are also removed.

Similarly, we update the User model:

class User < ApplicationRecord
  has_many :posts, dependent: :destroy
  has_many :comments, dependent: :destroy
end

This ensures that when a user account is deleted, all their posts and comments are automatically removed.

Now that our comments resource is set up, we still need to customize it to fit the specific needs of Lorem News.