Game of Life multiplayer

Shared board via ROUTE scope: everyone on this page sees and edits the same 50×50 grid. Click to draw a cross pattern in your color.

200ms timer: a $app->setInterval() callback evolves the board every 200 milliseconds and broadcasts the route. With shareRender: true the board renders once per tick for all viewers.

2,500 divs, no problem: each tick sends all 2,500 cells as plain HTML. No diffing, no virtual DOM, no clever protocol. The "stupid" solution just works because Brotli compression over SSE is absurdly efficient: 18 seconds of continuous updates transferred only 58 KB over the wire from 15 MB of raw HTML, roughly 250× compression.

No canvas, no JS drawing: the grid is a flat CSS Grid of server-rendered <div> elements with color classes. Datastar morphs them in place. The entire rendering pipeline is PHP string concatenation.

Why this matters: frameworks that diff on the client or send fine-grained patches add complexity for marginal gains. SSE + Brotli makes the brute-force approach viable even at 5 fps with thousands of elements, which covers the vast majority of real-world UIs.

Color identity: each tab gets the next of six colors, so the crosses of different players usually look different.

Lazy timer: the timer skips its work while countClients() finds nobody on this page, on any worker. Re-open the page and the board resumes from where it left off.

Collaborative drawing: every click is an action that mutates the shared board, then broadcasts the result. Multiple users can sculpt patterns together in real time.

One worker: this demo keeps the board in PHP statics, which each worker holds on its own. See What stays per worker before you run it with withWorkerNum().