Deno•3y ago

Server Sent Events with Fresh

Hi! I am trying to use Server Sent Events (SSE) with fresh. I understand I should have an island that holds the connection to the server but how can I broadcast the notifications to other islands?

Nnotiggsam Hi! I am trying to use Server Sent Events (SSE) with fresh. I understand I shoul...

again•4/6/23, 3:57 PM

it seems like it is actually not supported on Deno (server-side) https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events#browser_compatibility

Using server-sent events - Web APIs | MDN

Developing a web application that uses server-sent events is straightforward. You'll need a bit of code on the server to stream events to the front-end, but the client side code works almost identically to websockets in part of handling incoming events. This is a one-way connection, so you can't send events from a client to a server.

notiggsamOP•4/6/23, 4:14 PM

My question was about client-side with Fresh's islands.

On server side you don't need any particular support, as it is plain HTTP. You just have to stream your events with

NDH•4/6/23, 5:18 PM

Client side would use an EventSource to subscribe to the stream, and POST to the server to publish messages. When you say other islands, do you mean other islands in the same browser tab, or other instances of the Deploy isolate, or other instances of the same deploy isolate in different browser tab?

NDH•4/6/23, 5:21 PM

If same tab, just us browser BroadcastChannel. If different isolates, use Deno BroadcastChannel on the server.

NDH•4/6/23, 5:23 PM

See
https://github.com/nhrones/Relay/blob/master/SSE-BC.png?raw=true

NDH•4/6/23, 5:38 PM

The following api code uses SSE + BroadcastChannel as a WRTC signalling service to connect two players over a WebRTC-Datachannel.
https://github.com/nhrones/FreshDiceRTC/tree/master/routes/api

notiggsamOP•4/9/23, 4:11 PM

Thank you @ndh3193 ! I would never have thought about using