Persistent SSE — live server clock

Streaming — auto-closes after 15 s

PatchElements vs PatchSignals

PatchElementsMorphs DOM fragment by id. Best for server-rendered HTML (lists, tables, paginated content).
PatchSignalsUpdates client signal values. Best for status, counters, flags. Client renders from signals.
BothCan be mixed in one SSE response. PatchSignals first, then PatchElements — signals are available when fragment renders.

data-on-signal-patch — react to incoming patches

Fires whenever PatchSignals arrives from any SSE. Receives the patch object. Useful for analytics, notifications, or triggering client-side animations when new data arrives.