class Blob

Ruby on Rails 8.0.4

Since v5.2.8.1

Available in: v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

Active Storage Blob

A blob is a record that contains the metadata about a file and a key for where that file resides on the service. Blobs can be created in two ways:

Ahead of the file being uploaded server-side to the service, via create_and_upload!. A rewindable io with the file contents must be available at the server for this operation.
Ahead of the file being directly uploaded client-side to the service, via create_before_direct_upload!.

The first option doesn’t require any client-side JavaScript integration, and can be used by any other back-end service that deals with files. The second option is faster, since you’re not using your own server as a staging point for uploads, and can work with deployments like Heroku that do not provide large amounts of disk space.

Blobs are intended to be immutable in as-so-far as their reference to a specific file goes. You’re allowed to update a blob’s metadata on a subsequent pass, but you should not update the key or change the uploaded file. If you need to create a derivative or otherwise change the blob, simply create a new blob and purge the old one.

Inherits from

ActiveStorage::Record

Namespace

Modules

Includes

Constants

ActiveStorage::Blob::MINIMUM_TOKEN_LENGTH

Methods (defined here)

Private methods

(6) Implementation detail — not part of the public API.

Methods (inherited)

From ActiveStorage::Blob::Analyzable (3)

From ActiveStorage::Blob::Identifiable (3)

From ActiveStorage::Blob::Representable (6)

From ActiveSupport::Concern (3)