# frozen_string_literal: true
require "active_support/core_ext/object/try"
module ActiveStorage
# Provides the class-level DSL for declaring an Active Record model's attachments.
module Attached::Model
extend ActiveSupport::Concern
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.
#
# To avoid N+1 queries, you can include the attached blobs in your query like so:
#
# User.with_attached_avatar
#
# 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.
#
# The system has been designed to having you go through the ActiveStorage::Attached::One
# proxy that provides the dynamic proxy to the associations and factory methods, like +attach+.
#
# If the +:dependent+ option isn't set, the attachment will be purged
# (i.e. destroyed) whenever the record is destroyed.
#
# If you need the attachment to use a service which differs from the globally configured one,
# pass the +:service+ option. For instance:
#
# class User < ActiveRecord::Base
# has_one_attached :avatar, service: :s3
# end
#
# 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
#
def has_one_attached(name, dependent: :purge_later, service: nil, strict_loading: false)
validate_service_configuration(name, service)
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?
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}", -> { includes("#{name}_attachment": :blob) }
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.
#
# To avoid N+1 queries, you can include the attached blobs in your query like so:
#
# Gallery.where(user: Current.user).with_attached_photos
#
# 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.
#
# The system has been designed to having you go through the ActiveStorage::Attached::Many
# proxy that provides the dynamic proxy to the associations and factory methods, like +#attach+.
#
# If the +:dependent+ option isn't set, all the attachments will be purged
# (i.e. destroyed) whenever the record is destroyed.
#
# If you need the attachment to use a service which differs from the globally configured one,
# pass the +:service+ option. For instance:
#
# class Gallery < ActiveRecord::Base
# has_many_attached :photos, service: :s3
# end
#
# 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
#
def has_many_attached(name, dependent: :purge_later, service: nil, strict_loading: false)
validate_service_configuration(name, service)
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
if ActiveStorage.replace_on_assign_to_many
attachment_changes["#{name}"] =
if attachables.none?
ActiveStorage::Attached::Changes::DeleteMany.new("#{name}", self)
else
ActiveStorage::Attached::Changes::CreateMany.new("#{name}", self, attachables)
end
else
ActiveSupport::Deprecation.warn \
"config.active_storage.replace_on_assign_to_many is deprecated and will be removed in Rails 7.1. " \
"Make sure that your code works well with config.active_storage.replace_on_assign_to_many set to true before upgrading. " \
"To append new attachables to the Active Storage association, prefer using `attach`. " \
"Using association setter would result in purging the existing attached attachments and replacing them with new ones."
if attachables.any?
attachment_changes["#{name}"] =
ActiveStorage::Attached::Changes::CreateMany.new("#{name}", self, #{name}.blobs + attachables)
end
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 do
def purge
deprecate(:purge)
each(&:purge)
reset
end
def purge_later
deprecate(:purge_later)
each(&:purge_later)
reset
end
private
def deprecate(action)
reflection_name = proxy_association.reflection.name
attached_name = reflection_name.to_s.partition("_").first
ActiveSupport::Deprecation.warn(<<-MSG.squish)
Calling `#{action}` from `#{reflection_name}` is deprecated and will be removed in Rails 7.1.
To migrate to Rails 7.1's behavior call `#{action}` from `#{attached_name}` instead: `#{attached_name}.#{action}`.
MSG
end
end
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 })
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
private
def validate_service_configuration(association_name, service)
if service.present?
ActiveStorage::Blob.services.fetch(service) do
raise ArgumentError, "Cannot configure service :#{service} for #{name}##{association_name}"
end
end
end
end
def attachment_changes # :nodoc:
@attachment_changes ||= {}
end
def changed_for_autosave? # :nodoc:
super || attachment_changes.any?
end
def initialize_dup(*) # :nodoc:
super
@active_storage_attached = nil
@attachment_changes = nil
end
def reload(*) # :nodoc:
super.tap { @attachment_changes = nil }
end
end
end