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.

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("/path/to/face.jpg"), filename: "face.jpg", content_type: "image/jpg")
person.avatar.attach(avatar_blob) # ActiveStorage::Blob object
# File lib/active_storage/attached/one.rb, line 22
def attach(attachable)
  blob_was = blob if attached?
  blob = create_blob_from(attachable)

  unless blob == blob_was
    transaction do
      detach
      write_attachment build_attachment(blob: blob)
    end

    blob_was.purge_later if blob_was && dependent == :purge_later
  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 lib/active_storage/attached/one.rb, line 43
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 lib/active_storage/attached/one.rb, line 12
def attachment
  record.public_send("#{name}_attachment")
end
detach() click to toggle source

Deletes the attachment without purging it, leaving its blob in place.

# File lib/active_storage/attached/one.rb, line 48
def detach
  if attached?
    attachment.destroy
    write_attachment nil
  end
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 lib/active_storage/attached/one.rb, line 57
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 lib/active_storage/attached/one.rb, line 65
def purge_later
  if attached?
    attachment.purge_later
  end
end

Private Instance Methods

build_attachment(blob:) click to toggle source
# File lib/active_storage/attached/one.rb, line 74
def build_attachment(blob:)
  ActiveStorage::Attachment.new(record: record, name: name, blob: blob)
end
write_attachment(attachment) click to toggle source
# File lib/active_storage/attached/one.rb, line 78
def write_attachment(attachment)
  record.public_send("#{name}_attachment=", attachment)
end