class ActiveStorage::Attached::One

Representation of a single attachment to a model.

Public Instance Methods

attach(attachable) click to toggle source

Associates a given attachment with the current record, saving it to the database. Examples:

person.avatar.attach(params[:avatar]) # ActionDispatch::Http::UploadedFile object
person.avatar.attach(params[:signed_blob_id]) # Signed reference to blob from direct upload
person.avatar.attach(io: File.open("~/face.jpg"), filename: "face.jpg", content_type: "image/jpg")
person.avatar.attach(avatar_blob) # ActiveStorage::Blob object
# File activestorage/lib/active_storage/attached/one.rb, line 23
def attach(attachable)
  if attached? && dependent == :purge_later
    replace attachable
  else
    write_attachment create_attachment_from(attachable)
  end
end
attached?() click to toggle source

Returns true if an attachment has been made.

class User < ActiveRecord::Base
  has_one_attached :avatar
end

User.new.avatar.attached? # => false
# File activestorage/lib/active_storage/attached/one.rb, line 38
def attached?
  attachment.present?
end
attachment() click to toggle source

Returns the associated attachment record.

You don't have to call this method to access the attachment's methods as they are all available at the model level.

# File activestorage/lib/active_storage/attached/one.rb, line 12
def attachment
  record.public_send("#{name}_attachment")
end
purge() click to toggle source

Directly purges the attachment (i.e. destroys the blob and attachment and deletes the file on the service).

# File activestorage/lib/active_storage/attached/one.rb, line 44
def purge
  if attached?
    attachment.purge
    write_attachment nil
  end
end
purge_later() click to toggle source

Purges the attachment through the queuing system.

# File activestorage/lib/active_storage/attached/one.rb, line 52
def purge_later
  if attached?
    attachment.purge_later
  end
end

Private Instance Methods

create_attachment_from(attachable) click to toggle source
# File activestorage/lib/active_storage/attached/one.rb, line 68
def create_attachment_from(attachable)
  ActiveStorage::Attachment.create!(record: record, name: name, blob: create_blob_from(attachable))
end
replace(attachable) click to toggle source
# File activestorage/lib/active_storage/attached/one.rb, line 59
def replace(attachable)
  blob.tap do
    transaction do
      destroy
      write_attachment create_attachment_from(attachable)
    end
  end.purge_later
end
write_attachment(attachment) click to toggle source
# File activestorage/lib/active_storage/attached/one.rb, line 72
def write_attachment(attachment)
  record.public_send("#{name}_attachment=", attachment)
end