chaosc-cosmdisplay/cosm.js

var restify = require('restify')
    , util = require('util')
    , EventEmitter = require('events').EventEmitter;

// constructor function
function Cosm(streams, key) {
    var self = this;

    self._streams = streams;
    self._interval = 5000;

    self._jsonClient = restify.createJsonClient({
        url: 'http://api.cosm.com',
        headers: { 'X-ApiKey': key },
        version:'*'
    });

    var recentvalues = {};

    setInterval(function() {

        for(var i=0; i<streams.length; i++) {

            self._jsonClient.get('/v2/feeds/' + self._streams[i] + ".json", function(err, req, res, obj) {
                if(err || obj.datastreams == null) {
                    console.error("error getting stream: " + err)
                    return;
                }


                for(var i=0; i<obj.datastreams.length; i++) {
                    var dataStream = obj.datastreams[i];
                    if(dataStream.id == null) continue;

                    var streamName = dataStream.id;
                    if(streamName.length < 2 && dataStream.tags != null) {
                        streamName = dataStream.tags[0] + streamName;
                    }

                    var currentValue = dataStream.current_value;

                    if(isNumber(currentValue)) currentValue = parseFloat(currentValue);

                    var object = {
                        'stream': obj.id,
                        'feed': dataStream.id,
                        'tags': dataStream.tags,
                        'displayname': streamName,
                        'value': currentValue
                    };

                    var address = obj.id + ":" + dataStream.id;

                    console.log(recentvalues);
                    if(recentvalues[address] != currentValue) {
                        self.emit('changedvalue', object);
                    }
                    else
                        self.emit('updatevalue', object);


                    recentvalues[address] = currentValue;
                }
            });
        }

    }, self._interval);
}

util.inherits(Cosm, EventEmitter);

Cosm.prototype.getStreams = function(streams, callback) {
    var self = this;

    for(var i=0; i<streams.length; i++) {

        self._jsonClient.get('/v2/feeds/' + streams[i] + ".json", function(err, req, res, obj) {
            if(err || obj.datastreams == null) {
                console.error("error getting stream: " + err)
                return;
            }
//             console.dir(obj);
            var object = {
                id: obj.id,
                description: obj.description,
                lat: typeof obj.location === 'undefined' ? 'undefined' : obj.location.lat,
                lon: typeof obj.location === 'undefined' ? 'undefined' : obj.location.lon,
                location: typeof obj.location === 'undefined' ? 'undefined' :obj.location.name,
                title: obj.title
            };

            if(callback != 'undefined') callback(object);

        });
    }
};



module.exports = Cosm;



function isNumber(value) {
    if ((undefined === value) || (null === value)) {
        return false;
    }
    if (typeof value == 'number') {
        return true;
    }
    return !isNaN(value - 0);
}