ruby-on-rails – 如何解决ActiveStorage URL的N 1？

你如何用他们的URL预加载所有记录？

这是我在jbuilder中为获取URL而做的事情：

# views/users/index.json.jbuilder
...
json.avatar_url user.avatar.attached? && rails_blob_url(user.avatar)
...


Comment
    has_one :user

User
    has_one_attached :avatar

你会如何预加载所有用户及其头像？

Comments.includes(users: :avatar)

产生以下错误：

ActiveRecord::AssociationNotFoundError (Association named ‘avatar’ was not found on User; perhaps you misspelled it?)

执行时弹出相同的错误：

User.includes(:avatar)

对于名为avatar的单个附件,Active Storage会添加一个with_attached_avatar范围,用于预加载相关关联：

@users.with_attached_avatar.each do |user|
  # ...
end

请参阅has_one_attached的API文档.