I haven't found a solution to this issue yet either and it's causing orphaned files in our S3 bucket (that our app does not know about) which we need to clean up later.
How to reproduce the issue:
- Setup filepicker pickandstore to allow multiple file uploads.
- Upload 5 files.
- Let three complete.
- Close Filepicker window.
Issue: We never receive a partial JS callback for the three successes letting me know that three files are now sitting in my s3 bucket.
Two proposed solutions: 1. For multiple uploads, need a callback when all are complete/failed/window-was-closed with which arrays for which files were successful and which were failures. I like this option more. 2. Have a success/failure callback PER file?