title: Active Storage: Best practice to retain/cache uploaded file when form redisplays
body: <p>When uploading files with Active Storage, when a file is finished uploading and the form gets redisplayed, for example when the validation for that form fails for some reason, the file is gone.</p>
  
  <p>Is there a way to cache or retain it between form redisplays? <a href="https://shrinerb.com/rdoc/classes/Shrine/Plugins/CachedAttachmentData" rel="noreferrer">Shrine has a nice Plugin</a> for that purpose, I'm looking for something similar for Active Storage.</p>