# frozen_string_literal: true
module ActiveStorage
# Provides the class-level DSL for declaring that an Active Record model has attached blobs.
module Attached::Macros
# Specifies the relation between a single attachment and the model.
#
# class User < ActiveRecord::Base
# 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.
def has_one_attached(name, dependent: :purge_later)
class_eval <<-CODE, __FILE__, __LINE__ + 1
def #{name}
@active_storage_attached_#{name} ||= ActiveStorage::Attached::One.new("#{name}", self, dependent: #{dependent == :purge_later ? ":purge_later" : "false"})
end
CODE
has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record
has_one :"#{name}_blob", through: :"#{name}_attachment", class_name: "ActiveStorage::Blob", source: :blob
scope :"with_attached_#{name}", -> { includes("#{name}_attachment": :blob) }
if dependent == :purge_later
before_destroy { public_send(name).purge_later }
end
end
# Specifies the relation between multiple attachments and the model.
#
# class Gallery < ActiveRecord::Base
# 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.
def has_many_attached(name, dependent: :purge_later)
class_eval <<-CODE, __FILE__, __LINE__ + 1
def #{name}
@active_storage_attached_#{name} ||= ActiveStorage::Attached::Many.new("#{name}", self, dependent: #{dependent == :purge_later ? ":purge_later" : "false"})
end
CODE
has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment"
has_many :"#{name}_blobs", through: :"#{name}_attachments", class_name: "ActiveStorage::Blob", source: :blob
scope :"with_attached_#{name}", -> { includes("#{name}_attachments": :blob) }
if dependent == :purge_later
before_destroy { public_send(name).purge_later }
end
end
end
end