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@modeswitch

modeswitch/app.js

Last active August 29, 2015 14:05
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  1. Alan K renamed this gist Sep 2, 2014. 1 changed file with 0 additions and 0 deletions.
    0 gistfile1.txt → index.html
    View file
    File renamed without changes.
  2. Alan K created this gist Sep 2, 2014.
    68 changes: 68 additions & 0 deletions app.js
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    var dgram = require('dgram');
    var path = require('path');
    var express = require('express');
    var EventEmitter = require('events').EventEmitter;

    var app = express();
    var port = process.env.PORT = 9080;
    var router = express.Router();
    var socket = dgram.createSocket('udp4');
    var scanEvents = new EventEmitter();

    router.route('/stream').get(function(req, res) {
    console.log('/api/stream');
    var msgCount = 0;

    function handleMessage(msg) {
    ++ msgCount;

    msg = JSON.parse(msg.toString());

    switch(msg.data.type) {
    case "SignalStrength":
    msg.data.value = (200 - msg.data.value)/2; // convert poor signal value (200-0) to signal quality (0-100);
    break;
    case "EEG":
    break
    default:
    break;
    }


    res.write('id: ' + msgCount + '\n');
    res.write('data: ' + JSON.stringify(msg) + '\n\n');
    console.log(JSON.stringify(msg));
    }

    scanEvents.on('message', handleMessage);

    res.writeHead(200, {
    'Content-Type': 'text/event-stream',
    'Cache-Control': 'no-cache',
    'Connection': 'keep-alive',
    });
    res.write('\n');

    res.on('close', function() {
    scanEvents.removeListener('message', handleMessage);
    });
    });

    router.get('/', function(req, res) {
    res.json("API");
    });

    app.use(express.static(path.join(__dirname, 'html')));
    app.use('/api', router);

    app.get('/', function(req, res) {
    res.sendfile(path.join(__dirname, '/html/index.html'));
    });

    app.listen(port, function() {
    console.log("Listening on port %d", port);
    socket.bind(9000);
    socket.on('message', function(msg, rinfo) {
    scanEvents.emit('message', msg);
    });
    });
    42 changes: 42 additions & 0 deletions gistfile1.txt
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    <html>
    <body>
    [blah]
    </body>
    <script>
    var DEFAULT_DELAY = 2000;
    var source;

    function connect(msg, delay) {
    setTimeout(function() {
    console.log(msg);
    try {
    source = new EventSource('api/stream');
    source.onopen = function(e) {
    console.log('open');
    };

    source.onmessage = function(e) {
    console.log('message', e.data);
    };

    source.onerror = function(e) {
    switch(e.target.readyState) {
    case EventSource.CONNECTING:
    console.error('reconnecting ...');
    break;
    case EventSource.CLOSED:
    console.error('connection failed; no retry');
    connect('reconnecting ...', DEFAULT_DELAY);
    break;
    }
    };
    } catch(e) {
    console.error(e);
    connect('reconnecting ...', DEFAULT_DELAY);
    }
    }, delay);
    }

    connect('connecting ...', 0);
    </script>
    </html>
    9 changes: 9 additions & 0 deletions package.json
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    {
    "name": "blah",
    "description": "blah",
    "version": "0.0.1",
    "private": true,
    "dependencies": {
    "express": "3.x"
    }
    }