Representation of a single attachment to a model.

Methods

Instance Public methods

attach(attachable)

Attaches an attachable to the record.

If the record is persisted and unchanged, the attachment is saved to the database immediately. Otherwise, it’ll be saved to the DB when the record is next saved.

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/jpeg")
person.avatar.attach(avatar_blob) # ActiveStorage::Blob object
📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 56
    def attach(attachable)
      if record.persisted? && !record.changed?
        record.public_send("#{name}=", attachable)
        record.save
      else
        record.public_send("#{name}=", attachable)
      end
    end
🔎 See on GitHub

attached?()

Returns true if an attachment has been made.

class User < ApplicationRecord
  has_one_attached :avatar
end

User.new.avatar.attached? # => false
📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 72
    def attached?
      attachment.present?
    end
🔎 See on GitHub

attachment()

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.

📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 31
    def attachment
      change.present? ? change.attachment : record.public_send("#{name}_attachment")
    end
🔎 See on GitHub

blank?()

Returns true if an attachment is not attached.

class User < ApplicationRecord
  has_one_attached :avatar
end

User.new.avatar.blank? # => true
📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 42
    def blank?
      !attached?
    end
🔎 See on GitHub

detach

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

📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 23
    delegate :detach, to: :detach_one
🔎 See on GitHub

purge

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

📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 11
    delegate :purge, to: :purge_one
🔎 See on GitHub

purge_later

Purges the attachment through the queuing system.

📝 Source code 
# File activestorage/lib/active_storage/attached/one.rb, line 17
    delegate :purge_later, to: :purge_one
🔎 See on GitHub