Class: ActiveStorage::Attached::One
| Relationships & Source Files | |
| Super Chains via Extension / Inclusion / Inheritance | |
| Class Chain: | |
| Instance Chain: | |
| Inherits: | ActiveStorage::Attached 
 | 
| Defined in: | activestorage/lib/active_storage/attached/one.rb | 
Overview
Representation of a single attachment to a model.
Class Method Summary
::ActiveStorage::Attached - Inherited
Instance Attribute Summary
- 
    
      #attached?  ⇒ Boolean 
    
    readonly
    Returns trueif an attachment has been made.
- 
    
      #blank?  ⇒ Boolean 
    
    readonly
    Returns trueif an attachment is not attached.
- 
    
      #detach  
    
    readonly
    Deletes the attachment without purging it, leaving its blob in place. 
- 
    
      #purge  
    
    readonly
    Directly purges the attachment (i.e. 
- 
    
      #purge_later  
    
    readonly
    Purges the attachment through the queuing system. 
::ActiveStorage::Attached - Inherited
Instance Method Summary
- 
    
      #attach(attachable)  
    
    Attaches an attachableto the record.
- 
    
      #attachment  
    
    Returns the associated attachment record. 
- #detach_one private
- #purge_one private
::ActiveStorage::Attached - Inherited
Constructor Details
This class inherits a constructor from ActiveStorage::Attached
Instance Attribute Details
    #attached?  ⇒ Boolean  (readonly)
  
Returns true if an attachment has been made.
class User < ApplicationRecord
  has_one_attached :avatar
end
User.new.avatar.attached? # => false# File 'activestorage/lib/active_storage/attached/one.rb', line 73
def attached? .present? end
    #blank?  ⇒ Boolean  (readonly)
  
Returns true if an attachment is not attached.
class User < ApplicationRecord
  has_one_attached :avatar
end
User.new.avatar.blank? # => true# File 'activestorage/lib/active_storage/attached/one.rb', line 44
def blank? !attached? end
#detach (readonly)
Deletes the attachment without purging it, leaving its blob in place.
# File 'activestorage/lib/active_storage/attached/one.rb', line 25
delegate :detach, to: :detach_one
#purge (readonly)
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 13
delegate :purge, to: :purge_one
#purge_later (readonly)
Purges the attachment through the queuing system.
# File 'activestorage/lib/active_storage/attached/one.rb', line 19
delegate :purge_later, to: :purge_one
Instance Method Details
#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#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.