ActiveStorage::Attached::Model - Ruby on Rails 中文

*_attachment 链接

返回 has_one_attached 的附件。

User.last.avatar_attachment

来源: 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 13

*_attachments 链接

返回 has_many_attached 的附件。

Gallery.last.photos_attachments

来源: 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 20

*_blob 链接

返回 has_one_attached 附件的 blob。

User.last.avatar_blob

来源: 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 27

*_blobs 链接

返回 has_many_attached 附件的 blob。

Gallery.last.photos_blobs

来源: 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 34

has_many_attached(name, dependent: :purge_later, service: nil, strict_loading: false) 链接

指定多个附件与模型之间的关系。

class Gallery < ApplicationRecord
  has_many_attached :photos
end

模型端没有定义任何列，Active Storage 会处理记录与附件之间的映射。

在底层，这种关系被实现为对 ActiveStorage::Attachment 记录的 has_many 关联和对 ActiveStorage::Blob 记录的 has_many-through 关联。这些关联可以用 photos_attachments 和 photos_blobs 获取。但在大多数情况下，你不需要直接使用这些关联。

相反，has_many_attached 会生成一个 ActiveStorage::Attached::Many 代理，以提供对关联和工厂方法（如 attach）的访问。

user.photos.attach(uploaded_file)

:dependent 选项默认值为 :purge_later。这意味着每当记录被销毁时，附件将在后台被清除（即销毁）。如果应用程序中没有设置 ActiveJob::Backend 队列适配器，则将其设置为 purge。

如果你需要附件使用与全局配置不同的服务，请传递 :service 选项。例如

class Gallery < ActiveRecord::Base
  has_many_attached :photos, service: :s3
end

:service 也可以指定为 proc，它将使用模型实例进行调用

class Gallery < ActiveRecord::Base
  has_many_attached :photos, service: ->(gallery) { gallery.personal? ? :personal_s3 : :s3 }
end

为了避免 N+1 查询，你可以将附件的 blob 包含在你的查询中，如下所示

Gallery.where(user: Current.user).with_attached_photos

如果你需要启用 strict_loading 以防止附件的延迟加载，请传递 :strict_loading 选项。你可以这样做

class Gallery < ApplicationRecord
  has_many_attached :photos, strict_loading: true
end

注意：Active Storage 依赖于多态关联，这反过来会在数据库中存储类名。当重命名使用 has_many 的类时，请确保还更新相应行的 active_storage_attachments.record_type 多态类型列中的类名。

来源: 显示 | 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 210
      def has_many_attached(name, dependent: :purge_later, service: nil, strict_loading: false)
        ActiveStorage::Blob.validate_service_configuration(service, self, name) unless service.is_a?(Proc)

        generated_association_methods.class_eval <<-CODE, __FILE__, __LINE__ + 1
          # frozen_string_literal: true
          def #{name}
            @active_storage_attached ||= {}
            @active_storage_attached[:#{name}] ||= ActiveStorage::Attached::Many.new("#{name}", self)
          end

          def #{name}=(attachables)
            attachables = Array(attachables).compact_blank
            pending_uploads = attachment_changes["#{name}"].try(:pending_uploads)

            attachment_changes["#{name}"] = if attachables.none?
              ActiveStorage::Attached::Changes::DeleteMany.new("#{name}", self)
            else
              ActiveStorage::Attached::Changes::CreateMany.new("#{name}", self, attachables, pending_uploads: pending_uploads)
            end
          end
        CODE

        has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment", inverse_of: :record, dependent: :destroy, strict_loading: strict_loading
        has_many :"#{name}_blobs", through: :"#{name}_attachments", class_name: "ActiveStorage::Blob", source: :blob, strict_loading: strict_loading

        scope :"with_attached_#{name}", -> {
          if ActiveStorage.track_variants
            includes("#{name}_attachments": { blob: {
              variant_records: { image_attachment: :blob },
              preview_image_attachment: { blob: { variant_records: { image_attachment: :blob } } }
            } })
          else
            includes("#{name}_attachments": :blob)
          end
        }

        after_save { attachment_changes[name.to_s]&.save }

        after_commit(on: %i[ create update ]) { attachment_changes.delete(name.to_s).try(:upload) }

        reflection = ActiveRecord::Reflection.create(
          :has_many_attached,
          name,
          nil,
          { dependent: dependent, service_name: service },
          self
        )
        yield reflection if block_given?
        ActiveRecord::Reflection.add_attachment_reflection(self, name, reflection)
      end

has_one_attached(name, dependent: :purge_later, service: nil, strict_loading: false) 链接

指定单个附件与模型之间的关系。

class User < ApplicationRecord
  has_one_attached :avatar
end

模型端没有定义任何列，Active Storage 会处理记录与附件之间的映射。

在底层，这种关系被实现为对 ActiveStorage::Attachment 记录的 has_one 关联和对 ActiveStorage::Blob 记录的 has_one-through 关联。这些关联可以用 avatar_attachment 和 avatar_blob 获取。但在大多数情况下，你不需要直接使用这些关联。

相反，has_one_attached 会生成一个 ActiveStorage::Attached::One 代理，以提供对关联和工厂方法（如 attach）的访问。

user.avatar.attach(uploaded_file)

:dependent 选项默认值为 :purge_later。这意味着每当记录被销毁时，附件将在后台被清除（即销毁）。如果应用程序中没有设置 ActiveJob::Backend 队列适配器，则将其设置为 purge。

如果你需要附件使用与全局配置不同的服务，请传递 :service 选项。例如

class User < ActiveRecord::Base
  has_one_attached :avatar, service: :s3
end

:service 也可以指定为 proc，它将使用模型实例进行调用

class User < ActiveRecord::Base
  has_one_attached :avatar, service: ->(user) { user.in_europe_region? ? :s3_europe : :s3_usa }
end

为了避免 N+1 查询，你可以将附件的 blob 包含在你的查询中，如下所示

User.with_attached_avatar

如果你需要启用 strict_loading 以防止附件的延迟加载，请传递 :strict_loading 选项。你可以这样做

class User < ApplicationRecord
  has_one_attached :avatar, strict_loading: true
end

注意：Active Storage 依赖于多态关联，这反过来会在数据库中存储类名。当重命名使用 has_one_attached 的类时，请确保还更新相应行的 active_storage_attachments.record_type 多态类型列中的类名。

来源: 显示 | 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 108
      def has_one_attached(name, dependent: :purge_later, service: nil, strict_loading: false)
        ActiveStorage::Blob.validate_service_configuration(service, self, name) unless service.is_a?(Proc)

        generated_association_methods.class_eval <<-CODE, __FILE__, __LINE__ + 1
          # frozen_string_literal: true
          def #{name}
            @active_storage_attached ||= {}
            @active_storage_attached[:#{name}] ||= ActiveStorage::Attached::One.new("#{name}", self)
          end

          def #{name}=(attachable)
            attachment_changes["#{name}"] =
              if attachable.nil? || attachable == ""
                ActiveStorage::Attached::Changes::DeleteOne.new("#{name}", self)
              else
                ActiveStorage::Attached::Changes::CreateOne.new("#{name}", self, attachable)
              end
          end
        CODE

        has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record, inverse_of: :record, dependent: :destroy, strict_loading: strict_loading
        has_one :"#{name}_blob", through: :"#{name}_attachment", class_name: "ActiveStorage::Blob", source: :blob, strict_loading: strict_loading

        scope :"with_attached_#{name}", -> {
          if ActiveStorage.track_variants
            includes("#{name}_attachment": { blob: {
              variant_records: { image_attachment: :blob },
              preview_image_attachment: { blob: { variant_records: { image_attachment: :blob } } }
            } })
          else
            includes("#{name}_attachment": :blob)
          end
        }

        after_save { attachment_changes[name.to_s]&.save }

        after_commit(on: %i[ create update ]) { attachment_changes.delete(name.to_s).try(:upload) }

        reflection = ActiveRecord::Reflection.create(
          :has_one_attached,
          name,
          nil,
          { dependent: dependent, service_name: service },
          self
        )
        yield reflection if block_given?
        ActiveRecord::Reflection.add_attachment_reflection(self, name, reflection)
      end

with_attached_* 链接

将附件的 blob 包含在你的查询中，以避免 N+1 查询。

如果启用了 ActiveStorage.track_variants，它还会包含变体记录及其附件的 blob。

User.with_attached_avatar

对于 has_many_attached，使用复数形式

Gallery.with_attached_photos

来源: 显示 | 在 GitHub 上

# File activestorage/lib/active_storage/attached/model.rb, line 54
    class_methods do
      # Specifies the relation between a single attachment and the model.
      #
      #   class User < ApplicationRecord
      #     has_one_attached :avatar
      #   end
      #
      # There is no column defined on the model side, Active Storage takes
      # care of the mapping between your records and the attachment.
      #
      # Under the covers, this relationship is implemented as a +has_one+ association to a
      # ActiveStorage::Attachment record and a +has_one-through+ association to a
      # ActiveStorage::Blob record. These associations are available as +avatar_attachment+
      # and +avatar_blob+. But you shouldn't need to work with these associations directly in
      # most circumstances.
      #
      # Instead, +has_one_attached+ generates an ActiveStorage::Attached::One proxy to
      # provide access to the associations and factory methods, like +attach+:
      #
      #   user.avatar.attach(uploaded_file)
      #
      # The +:dependent+ option defaults to +:purge_later+. This means the attachment will be
      # purged (i.e. destroyed) in the background whenever the record is destroyed.
      # If an ActiveJob::Backend queue adapter is not set in the application set it to
      # +purge+ instead.
      #
      # If you need the attachment to use a service which differs from the globally configured one,
      # pass the +:service+ option. For example:
      #
      #   class User < ActiveRecord::Base
      #     has_one_attached :avatar, service: :s3
      #   end
      #
      # +:service+ can also be specified as a proc, and it will be called with the model instance:
      #
      #   class User < ActiveRecord::Base
      #     has_one_attached :avatar, service: ->(user) { user.in_europe_region? ? :s3_europe : :s3_usa }
      #   end
      #
      # To avoid N+1 queries, you can include the attached blobs in your query like so:
      #
      #   User.with_attached_avatar
      #
      # If you need to enable +strict_loading+ to prevent lazy loading of attachment,
      # pass the +:strict_loading+ option. You can do:
      #
      #   class User < ApplicationRecord
      #     has_one_attached :avatar, strict_loading: true
      #   end
      #
      # Note: Active Storage relies on polymorphic associations, which in turn store class names in the database.
      # When renaming classes that use <tt>has_one_attached</tt>, make sure to also update the class names in the
      # <tt>active_storage_attachments.record_type</tt> polymorphic type column of
      # the corresponding rows.
      def has_one_attached(name, dependent: :purge_later, service: nil, strict_loading: false)
        ActiveStorage::Blob.validate_service_configuration(service, self, name) unless service.is_a?(Proc)

        generated_association_methods.class_eval <<-CODE, __FILE__, __LINE__ + 1
          # frozen_string_literal: true
          def #{name}
            @active_storage_attached ||= {}
            @active_storage_attached[:#{name}] ||= ActiveStorage::Attached::One.new("#{name}", self)
          end

          def #{name}=(attachable)
            attachment_changes["#{name}"] =
              if attachable.nil? || attachable == ""
                ActiveStorage::Attached::Changes::DeleteOne.new("#{name}", self)
              else
                ActiveStorage::Attached::Changes::CreateOne.new("#{name}", self, attachable)
              end
          end
        CODE

        has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record, inverse_of: :record, dependent: :destroy, strict_loading: strict_loading
        has_one :"#{name}_blob", through: :"#{name}_attachment", class_name: "ActiveStorage::Blob", source: :blob, strict_loading: strict_loading

        scope :"with_attached_#{name}", -> {
          if ActiveStorage.track_variants
            includes("#{name}_attachment": { blob: {
              variant_records: { image_attachment: :blob },
              preview_image_attachment: { blob: { variant_records: { image_attachment: :blob } } }
            } })
          else
            includes("#{name}_attachment": :blob)
          end
        }

        after_save { attachment_changes[name.to_s]&.save }

        after_commit(on: %i[ create update ]) { attachment_changes.delete(name.to_s).try(:upload) }

        reflection = ActiveRecord::Reflection.create(
          :has_one_attached,
          name,
          nil,
          { dependent: dependent, service_name: service },
          self
        )
        yield reflection if block_given?
        ActiveRecord::Reflection.add_attachment_reflection(self, name, reflection)
      end

      # Specifies the relation between multiple attachments and the model.
      #
      #   class Gallery < ApplicationRecord
      #     has_many_attached :photos
      #   end
      #
      # There are no columns defined on the model side, Active Storage takes
      # care of the mapping between your records and the attachments.
      #
      # Under the covers, this relationship is implemented as a +has_many+ association to a
      # ActiveStorage::Attachment record and a +has_many-through+ association to a
      # ActiveStorage::Blob record. These associations are available as +photos_attachments+
      # and +photos_blobs+. But you shouldn't need to work with these associations directly in
      # most circumstances.
      #
      # Instead, +has_many_attached+ generates an ActiveStorage::Attached::Many proxy to
      # provide access to the associations and factory methods, like +attach+:
      #
      #   user.photos.attach(uploaded_file)
      #
      # The +:dependent+ option defaults to +:purge_later+. This means the attachments will be
      # purged (i.e. destroyed) in the background whenever the record is destroyed.
      # If an ActiveJob::Backend queue adapter is not set in the application set it to
      # +purge+ instead.
      #
      # If you need the attachment to use a service which differs from the globally configured one,
      # pass the +:service+ option. For example:
      #
      #   class Gallery < ActiveRecord::Base
      #     has_many_attached :photos, service: :s3
      #   end
      #
      # +:service+ can also be specified as a proc, and it will be called with the model instance:
      #
      #   class Gallery < ActiveRecord::Base
      #     has_many_attached :photos, service: ->(gallery) { gallery.personal? ? :personal_s3 : :s3 }
      #   end
      #
      # To avoid N+1 queries, you can include the attached blobs in your query like so:
      #
      #   Gallery.where(user: Current.user).with_attached_photos
      #
      # If you need to enable +strict_loading+ to prevent lazy loading of attachments,
      # pass the +:strict_loading+ option. You can do:
      #
      #   class Gallery < ApplicationRecord
      #     has_many_attached :photos, strict_loading: true
      #   end
      #
      # Note: Active Storage relies on polymorphic associations, which in turn store class names in the database.
      # When renaming classes that use <tt>has_many</tt>, make sure to also update the class names in the
      # <tt>active_storage_attachments.record_type</tt> polymorphic type column of
      # the corresponding rows.
      def has_many_attached(name, dependent: :purge_later, service: nil, strict_loading: false)
        ActiveStorage::Blob.validate_service_configuration(service, self, name) unless service.is_a?(Proc)

        generated_association_methods.class_eval <<-CODE, __FILE__, __LINE__ + 1
          # frozen_string_literal: true
          def #{name}
            @active_storage_attached ||= {}
            @active_storage_attached[:#{name}] ||= ActiveStorage::Attached::Many.new("#{name}", self)
          end

          def #{name}=(attachables)
            attachables = Array(attachables).compact_blank
            pending_uploads = attachment_changes["#{name}"].try(:pending_uploads)

            attachment_changes["#{name}"] = if attachables.none?
              ActiveStorage::Attached::Changes::DeleteMany.new("#{name}", self)
            else
              ActiveStorage::Attached::Changes::CreateMany.new("#{name}", self, attachables, pending_uploads: pending_uploads)
            end
          end
        CODE

        has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment", inverse_of: :record, dependent: :destroy, strict_loading: strict_loading
        has_many :"#{name}_blobs", through: :"#{name}_attachments", class_name: "ActiveStorage::Blob", source: :blob, strict_loading: strict_loading

        scope :"with_attached_#{name}", -> {
          if ActiveStorage.track_variants
            includes("#{name}_attachments": { blob: {
              variant_records: { image_attachment: :blob },
              preview_image_attachment: { blob: { variant_records: { image_attachment: :blob } } }
            } })
          else
            includes("#{name}_attachments": :blob)
          end
        }

        after_save { attachment_changes[name.to_s]&.save }

        after_commit(on: %i[ create update ]) { attachment_changes.delete(name.to_s).try(:upload) }

        reflection = ActiveRecord::Reflection.create(
          :has_many_attached,
          name,
          nil,
          { dependent: dependent, service_name: service },
          self
        )
        yield reflection if block_given?
        ActiveRecord::Reflection.add_attachment_reflection(self, name, reflection)
      end
    end

模块 ActiveStorage::Attached::Model

Active Storage 附加模型

实例公共方法

*_attachment 链接

*_attachments 链接

*_blob 链接

*_blobs 链接

has_many_attached(name, dependent: :purge_later, service: nil, strict_loading: false) 链接

has_one_attached(name, dependent: :purge_later, service: nil, strict_loading: false) 链接

with_attached_* 链接