warning.js

var Warning = (function(){
   
   // web Audio API object     
   var sound = {
     init : function() {
       this.context = new webkitAudioContext();
       this.oscillator = this.context.createOscillator();
       this.oscillator.connect(this.context.destination);
       this.oscillator.type = 3;
       this.oscillator.frequency.value = 266;
     },
     play : function(num){
        var n = num || 0;
        var that = this;
        this.modulate = setInterval(function(){
            var f = (that.oscillator.frequency.value === 266) ? 238 : 266;
            that.oscillator.frequency.value = f;
        },200);
        this.oscillator.start(n);
     },
     stop : function(num){
        var n = num || 0;
        this.oscillator.stop(n);
        clearInterval(this.modulate);
     }
   };
   
   // functions for checking if server limits are too damn high 
   var _limit = 10,
        boxes = document.getElementsByClassName('box'),
        klaxon = 0,
        intvl;
   
   var warning = function(item,elm){
        if (item > _limit) {
           console.log(elm.children[1].textContent + ' is over ' +_limit);
           if (klaxon === 0){
            sound.play();
            klaxon = 1; // once warning sound has started we don't need to reload it for concurrent warnings
           }
        }
    };  

    var updateLimit = function(l){
        _limit = l || 10;
    };
    
    var check = function(){
        for (var i=0,len=boxes.length; i < len; i++) {
            var target = boxes[i].children[3].children[0];
            var val = parseFloat(target.textContent);
            warning(val,boxes[i]);
        }
    };
    
    var begin = function(time){
        sound.init();
        var t = time || 15;
        var finalT = t * 1000;
        intvl = setInterval(check, finalT);
    };
    
    var kill = function(){
        clearInterval(intvl);
        sound.stop();
        klaxon = 0;
    };
    
    return {
        begin : begin,
        kill : kill,
        stop : sound.stop,
        updateLimit : updateLimit
    };
});

window.warning = new Warning();