HTML5 WebWorker send & receive Number

Question

How to send a number to webworker ?
How to receive a number in webworker ?

if possible, How to do this without using json or javascript Object, because using it will add extra line of code ..

EDIT :

ew i got many downvote without knowing why .. i explain what i try to do..

i try to create timer in webworker

if i send string "start" to webworker, webworker will begin the interval( the timer )
if i send a number to webworker, webworker will set the duration of interval

but i don't know how to send a number,

i knew argument passed to webworker should be a string, i already read few tutorial,

but i still don't understand what to do so my webworker can recognize a number..

because i try parseInt() and is not work ..

here's my code

in HTML

window.onload = function(){

            var worker = new Worker("Thread.js");
            worker.postMessage("1500");     //set duration of interval
            worker.postMessage("start");    //start the interval


            worker.onmessage = function(e){
                document.body.innerHTML += '<p> worker receive: '+e.data+'</p>';
            }

            worker.onerror = function(e){
                document.body.innderHTML += "<p> worker error"+e.data+"</p>";
            }

    }

Thread.js

onmessage = function(e){

    var msg =  e.data ;
    var timer;
    var duration = 1000;    //default duration

    try{
        var number = parseInt(msg);
        msg = number;
    }catch(e){

    }

    //start the interval
    if(msg === "start"){
        timer = setInterval(function(){
            postMessage( "lalala" );
        }, duration);
    }

    else if(msg === "stop"){
        clearInterval(timer);
    }

    //set duration
    else if(!isNaN(msg)){
        duration = msg;
    }


}

http://stackoverflow.com/questions/4019230/javascript-web-workers-how-do-i-pass-arguments — Can, Oct 31 '14 at 13:41
The MDN has a nice tutorial about the WebWorker API: https://developer.mozilla.org/en-US/docs/Web/Guide/Performance/Using_web_workers — meskobalazs, Oct 31 '14 at 13:42
@CanŞahinBakır @ meskobalazs thank u for the reference sir.. but i still don't understand what to do ... i edit my question so it can more clear — user3578021, Oct 31 '14 at 14:29
@SebastienC. it doing nothing in chrome.. it should be add paragraph in document.body each interval — user3578021, Oct 31 '14 at 14:31

score 1 · Accepted Answer · answered Oct 31 '14 at 14:59

That doesn't work because parseInt doesn't throw an Error, it returns NaN (Not a Number).

You also have another bug: you need to declare timer and duration outside onmessage if you want both to persist between two messages.

Note that changing duration won't affect the interval unless you restart it.

var timer;
var duration = 1000;

onmessage = function(e) {
    var msg = e.data ;
    var number = parseInt(msg);

    if(msg === "start") {
        timer = setInterval(function() {
            postMessage( "lalala" );
        }, duration);
    } else if(msg === "stop") {
        clearInterval(timer);
    } else if(!isNaN(msg)) {
        duration = number;
    }
};

billion of thanks sir.. forgive my stupidity.. it make sense now — user3578021, Oct 31 '14 at 16:32

HTML5 WebWorker send & receive Number

1 Answers1