Small gist illustrating using has_one instead of belongs_to to take advantage of parent passing

code.rb

class Moderation
  belongs_to :content
end

class Content
  has_many :moderations
end

class ModerationResource < ApplicationResource
  type :'moderation'
  model ::Moderation

  # Note : use has_one despite having the belongs_to key to pass the moderation to the contentResource !
  has_one :content, resource: ::Moderation::ContentResource
end

class Moderation::Content < ApplicationResource
  type :'moderation'
  model ::Moderation

  def update(attributes, moderation)
    # If we had used a `belongs_to` in the resource, +moderation+ would be nil !
    ModerationService.new(moderation).update_content_attributes(attributes)
  end
end