class ActiveStorage::Attachment

User.first.avatars.with_all_variant_records
# preloads blobs and variant records (if using ‘ActiveStorage.track_variants`)
User.all.with_attached_avatars
# preloads attachments, their corresponding blobs, and variant records (if using `ActiveStorage.track_variants`)
If you wish to preload attachments or blobs, you can use these scopes:
Attachments also have access to all methods from ActiveStorage::Blob.
on the attachments table prevents blobs from being purged if they’re still attached to any records.
but it is possible to associate many different records with the same blob. A foreign-key constraint
Attachments associate records with blobs. Usually that’s a one record-many blobs relationship,

def analyze_blob_later 

def analyze_blob_later
  blob.analyze_later unless blob.analyzed?
end

def dependent 

def dependent
  record.attachment_reflections[name]&.options&.fetch(:dependent, nil)
end

def mirror_blob_later 

def mirror_blob_later
  blob.mirror_later
end

def purge

Synchronously deletes the attachment and {purges the blob}[rdoc-ref:ActiveStorage::Blob#purge]. 
def purge
  transaction do
    delete
    record.touch if record&.persisted?
  end
  blob&.purge
end

def purge_dependent_blob_later 

def purge_dependent_blob_later
  blob&.purge_later if dependent == :purge_later
end

def purge_later

Deletes the attachment and {enqueues a background job}[rdoc-ref:ActiveStorage::Blob#purge_later] to purge the blob. 
def purge_later
  transaction do
    delete
    record.touch if record&.persisted?
  end
  blob&.purge_later
end

def variant(transformations)

unknown pre-defined variant of the attachment.
Raises an +ArgumentError+ if +transformations+ is a +Symbol+ which is an

See ActiveStorage::Blob::Representable#variant for more information.
instance for the attachment with the set of +transformations+ provided.
Returns an ActiveStorage::Variant or ActiveStorage::VariantWithRecord 
def variant(transformations)
  case transformations
  when Symbol
    variant_name = transformations
    transformations = variants.fetch(variant_name) do
      record_model_name = record.to_model.model_name.name
      raise ArgumentError, "Cannot find variant :#{variant_name} for #{record_model_name}##{name}"
    end
  end
  blob.variant(transformations)
end

def variants 

def variants
  record.attachment_reflections[name]&.variants
end