PUB/SUB Over websockets #163

esatterwhite · 2016-09-19T19:22:06Z

I'm assuming this is a constraint of the nanomsg library, but is it possible to use the pub/sub sockets with a websocket transport? I was able to use the pair type as shown in the examples, but it won't connect using pub sub.

Does it only work with 2-way socket types?

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reqshark · 2016-09-19T21:56:01Z

pub sub works, and if you're using it in a browser, verify mapping

esatterwhite · 2016-09-20T00:52:14Z

Yeah, Im just running the ws example in this project. changed the client to sub.sp.nanomsg.org and the server to a pub socket type, The hand shake never completes and nothing will ever make it to the client. I put a send command in an interval and still nothing.

esatterwhite · 2016-09-20T00:52:56Z

Also, how would you add a subscription in the browser ?

reqshark · 2016-09-20T01:34:42Z

client and server paradigm is not always helpful when doing nanomsg. better to talk about endpoints and socket types. we bind subscribers and just as we bind publishers... and likewise with connect and all other interchangeable socket types.

anyway let's take a look at your use case and see if we cant get something to work based on the example:

`server.js`:

const pub = require('nanomsg').socket('pub')
const sub = require('nanomsg').socket('sub')

pub.bind('ws://127.0.0.1:7790')
sub.bind('ws://127.0.0.1:7791')

/* nanomsg websocket text frames */
pub.wsopt('text')
sub.wsopt('text')

setInterval(()=> pub.send('hello from nanomsg @ '+new Date()), 500)


sub.on('data', function(msg){
  //pub.send(msg+'');
  console.log('msg recv\'d: '+msg);
});

require('http').createServer(function (req, res) {
  require('fs').createReadStream('index.html').pipe(res);
}).listen(3000);

`index.html`:

<!DOCTYPE html>
<html>
  <head></head>
  <body>
    <p>nanomsg ws test:&nbsp;<span></span></p>
    <input type='text'>
    <button>send</button>
    <script>
      var ws = new WebSocket('ws://127.0.0.1:7790', [
      // see the rfc on sp websocket mapping:
      // raw.githubusercontent.com/nanomsg/nanomsg/master/rfc/sp-websocket-mapping-01.txt
        'pub.sp.nanomsg.org'
      ]);
      ws.onopen = function open() { }//do something
      ws.onerror = function error(err) { console.log(err); }
      ws.onmessage = function message(e) {
        document.querySelector('span').textContent = e.data
      }

      var sub = new WebSocket('ws://127.0.0.1:7791', [ 'sub.sp.nanomsg.org' ])
      sub.onclose = function eh(){}
      sub.onerror = function(){}
      sub.onopen = function(){}

      var input = document.querySelector('input');
      input.addEventListener('keydown', function(e){
        if (e.which === 13) {
          return send();
        }
      }, false);

      document
        .querySelector('button')
        .addEventListener('click', send, false);

      function send(e) {
        sub.send(input.value); // send input value
        input.value = '';     // clear input
      }

    </script>
  </body>
</html>

esatterwhite · 2016-09-20T02:06:05Z

Ah, so the browser connection mapping needs to match the server. That wasn't really clear. I was using pub on the server and sub in the browser.

esatterwhite · 2016-09-20T02:14:00Z

Is there a way to specify subscriptions on in the browser sub socket?

reqshark · 2016-09-20T03:42:49Z

Ah, so the browser connection mapping needs to match the server.

Exactly, nanosmg websocket options in the browser === not intuitive.

Is there a way to specify subscriptions on in the browser sub socket?

you mean like setting subscription channels? i don't think so, the issue came up once on libnanomsg, and from what i remember the answer is no

reqshark added the question label Sep 20, 2016

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PUB/SUB Over websockets #163

PUB/SUB Over websockets #163

esatterwhite commented Sep 19, 2016

reqshark commented Sep 19, 2016

esatterwhite commented Sep 20, 2016

esatterwhite commented Sep 20, 2016

reqshark commented Sep 20, 2016 •

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esatterwhite commented Sep 20, 2016 •

edited

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esatterwhite commented Sep 20, 2016

reqshark commented Sep 20, 2016

PUB/SUB Over websockets #163

PUB/SUB Over websockets #163

Comments

esatterwhite commented Sep 19, 2016

reqshark commented Sep 19, 2016

esatterwhite commented Sep 20, 2016

esatterwhite commented Sep 20, 2016

reqshark commented Sep 20, 2016 • edited Loading

server.js:

index.html:

esatterwhite commented Sep 20, 2016 • edited Loading

esatterwhite commented Sep 20, 2016

reqshark commented Sep 20, 2016

reqshark commented Sep 20, 2016 •

edited

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`server.js`:

`index.html`:

esatterwhite commented Sep 20, 2016 •

edited

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