Implementing Ui Bundle File Upload

This handles file uploads in Salesforce UI bundles through a programmatic API rather than pre-built components. You get an upload() function that manages progress tracking and ContentVersion creation, but you build the actual UI yourself with custom dropzones, file inputs, and progress bars. The workflow is smart: upload files immediately to get contentBodyIds, optionally link them to existing records right away, or defer the linking until after you create the parent record. Progress callbacks give you pending, uploading, processing, success, and error states with percentage completion. Worth noting it's strictly an API package, so don't expect useFileUpload hooks or ready-made React components despite what the example code might suggest.