Attachments associate records with blobs. Usually that's a one record-many blobs relationship, but it is possible to associate many different records with the same blob. A foreign-key constraint on the attachments table prevents blobs from being purged if they’re still attached to any records.
Attachments also have access to all methods from ActiveStorage::Blob
.
If you wish to preload attachments or blobs, you can use these scopes:
# preloads attachments, their corresponding blobs, and variant records (if using `ActiveStorage.track_variants`)
User.all.with_attached_avatars
# preloads blobs and variant records (if using `ActiveStorage.track_variants`)
User.first.avatars.with_all_variant_records
- P
- V
Instance Public methods
purge() Link
Synchronously deletes the attachment and purges the blob.
purge_later() Link
Deletes the attachment and enqueues a background job to purge the blob.
variant(transformations) Link
Returns an ActiveStorage::Variant
or ActiveStorage::VariantWithRecord
instance for the attachment with the set of transformations
provided. See ActiveStorage::Blob::Representable#variant
for more information.
Raises an ArgumentError
if transformations
is a Symbol
which is an unknown pre-defined variant of the attachment.
# File activestorage/app/models/active_storage/attachment.rb, line 56 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