rails-docstore/app/models/document.rb

class Document < ApplicationRecord
  belongs_to :user
  belongs_to :category
  has_one :content, dependent: :destroy, required: false
  has_and_belongs_to_many :tags

  validates :category, :doc, presence: true 

  has_attached_file :doc,
  {
    styles: { thumb: ["200x", :png] },
    adapter_options: { hash_digest: Digest::SHA256 },
    url: "/system/:class/:attachment/:id_partition/:style/:hash.:extension",
    hash_secret: Rails.application.secrets.secret_key_base
  }
  validates_attachment_content_type :doc, content_type: 'application/pdf'

  after_save :generate_content

  scope :contains_word, -> (word) { joins(:content).where("text like ?", "%#{word}%") }
  scope :belongs_to_category, -> (category_id) { where(category_id: category_id ) }

  private
    def generate_content
      if self.doc_content_type == 'application/pdf'
        ContentGenerationJob.perform_now self.id
      end
    end
end