Make server web page content auto-update when content file changes

[stelcodes]

It would be awesome to have a truly hot-reloading web server that updates the web page when the associated content file is modified. I would have to change the ring app to be async I think and use http-kit's support for websockets. Then on the server I could poll the .lastModified time of the content file every second and upon a modification I could send an event to the client JS via WebSocket that contains the full HTML or possibly just the body element. Then the client JS could replace the body tag with the new one from the WebSocket.

I should probably just send a WebSocket message every second from the client to the server to make sure that it's still open. I don't think sending small messages every second would waste that many CPU cycles. I don't want to get into a state where the server is polling the file forever even though the WebSocket is closed. I think the server will have to poll both the file and the client JS.

[stelcodes]

JS Techniques

Use WebSocket API directly

• Well supported
  https://developer.mozilla.org/en-US/docs/Web/API/WebSocket

Options

Vanilla JS

• Could just slurp from .js file
• Simplest, probably should start here

Cherry

• Write client JS in JVM Clojure files
• Simple compilation, not sure how easy it is to work with
  https://github.com/borkdude/bb-cherry-example/blob/main/src/bb_cherry/app.clj

ClojureScript

• Possibly overkill
• Professionally useful maybe?