获取多态关联以通过验证

class CreateComments < ActiveRecord::Migration[6.1]
  def change
    create_table :comments do |t|
      t.text :body
      t.references :commentable, polymorphic: true, index: true
      t.timestamps
    end
  end
end

class Comment < ApplicationRecord
  belongs_to :commentable, polymorphic: true
end

class Article < ApplicationRecord
  has_many :comments, as: :commentable
end

class Page < ApplicationRecord
  has_many :comments, as: :commentable
end

# 创建一个文章
article = Article.create(title: 'Sample Article', content: 'This is a sample article.')

# 为文章添加评论
comment1 = Comment.create(body: 'Great article!', commentable: article)

# 创建一个页面
page = Page.create(title: 'Sample Page', content: 'This is a sample page.')

# 为页面添加评论
comment2 = Comment.create(body: 'Nice page!', commentable: page)

# 获取文章的所有评论
article.comments.each do |comment|
  puts comment.body
end

# 获取页面的所有评论
page.comments.each do |comment|
  puts comment.body
end

class Comment < ApplicationRecord
  belongs_to :commentable, polymorphic: true

  validates :commentable_type, inclusion: { in: %w(Article Page) }
end