LiveView Streams

Phoenix LiveView streams (0.19+) provide efficient rendering of large collections by patching only changed DOM elements.

RULES — Follow these with no exceptions

1. Use streams for collections with 100+ items — regular assigns re-render the entire list on every change
2. Initialize streams in mount/3 with stream(socket, :name, collection)
3. Use stream_insert/3 and stream_delete/3 for incremental updates — never replace the entire stream
4. Use phx-update="stream" in templates — required for stream DOM patching
5. Set DOM IDs with id attribute — each streamed item needs a unique DOM ID
6. Use stream_configure/3 for custom DOM IDs — when default IDs don't match your needs
7. Combine with pagination or infinite scroll — don't stream unlimited items
8. Always use Repo.preload before streaming — preloading ensures data is loaded
9. Use at: option for ordered insertion — control where new items appear in the stream

End-to-End Workflow