examples/simple.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Simple</title>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"
          crossorigin="anonymous">
</head>
<body>
<!-- a place to record messages -->
<div id="messages" class="container"></div>
<!-- load a script -->
<script type="module">
  import { connect, StringCodec } from '../nats.js'

  // add an entry to the document
  function addEntry(s) {
    const p = document.createElement("pre");
    p.appendChild(document.createTextNode(s));
    document.getElementById("messages").appendChild(p);
  }

  const sc = StringCodec();

  const init = async function () {
    // create a connection
    const nc = await connect({ servers: 'ws://localhost:9222' })
    addEntry('connected to NATS!');

    // simple publisher
    nc.publish('hello', sc.encode('nats'))
    addEntry('published a message to `hello`');

    // simple subscriber, if the message has a reply subject
    // send a reply
    const sub = await nc.subscribe('help');
    (async () => {
      addEntry('listening for request on `help`');
      for await (const m of sub) {
        m.respond(sc.encode(`I can help ${sc.decode(m.data)}`));
      }
    })().then()

    // request data - requests only receive one message
    // to receive multiple messages, create a subscription
    addEntry('making a request to `help`');
    const msg = await nc.request('help', sc.encode('nats request'))

    addEntry(`got response '${sc.decode(msg.data)}'`);

    // close the connection
    nc.close();
    addEntry('closed the connection');
  }
  init();
</script>
</body>
</html>