🔗 Phoenix LiveView file uploads with auto-recovery on server restarts

While Phoenix LiveView handles many aspects of file uploads elegantly, managing server restarts and deploys on forms with uploads is not completely handled by default. The auto-recovery mechanism works well for regular form fields so that if a server restart occurs while a user is filling out a form, all the standard fields are recovered automatically. However, file uploads are not.

In this post, I’ll walk through a robust approach to managing file uploads in LiveView that survive server restarts and provide a seamless user experience.

We’ll build a blog post system with document uploads using a step-by-step approach. Each Post can have multiple associated Document files that users can upload through both “new” and “edit” forms. Starting with basic upload functionality, we’ll progressively add auto-recovery and cleanup mechanisms.

Note that we’ll use the Waffle and Waffle.Ecto libraries to handle file uploads.