If I put a window.alert on a webworker client, then the background worker stops working. Why is this so?
i.e. The caller:
var worker = new Worker("worker.js");
// Watch for messages from the worker
worker.onmessage = function(e){
// The message from the client:
e.data
};
worker.postMessage("start");
The client (worker.js)
onmessage = function(e){
if ( e.data === "start" ) {
// Do some putation
done()
}
};
function done(){
alert('don'); // ===> This kills the worker.
// Send back the results to the parent page
postMessage("done");
}
If I put a window.alert on a webworker client, then the background worker stops working. Why is this so?
i.e. The caller:
var worker = new Worker("worker.js");
// Watch for messages from the worker
worker.onmessage = function(e){
// The message from the client:
e.data
};
worker.postMessage("start");
The client (worker.js)
onmessage = function(e){
if ( e.data === "start" ) {
// Do some putation
done()
}
};
function done(){
alert('don'); // ===> This kills the worker.
// Send back the results to the parent page
postMessage("done");
}
3 Answers
Reset to default 2Has you have noticed the alert freezes the javascript engine until the user clicks OK.
If you don't want it to freeze don't use alerts.
For debuging with firebug:
console.log("bla bla bla");
For non locking popups:
make a hidden div with an ok button on it. When the popup is to be shown. Put the div visible. When the user clicks the "ok" hide it.
I would advise you not to use popups. It also breaks the "work flow" (meaning the concentration of the user) of the user behind the screen :)
does the web worker have access to window.alert...i know web workers do not get dom access..
in the worker, why not do a
if (window && window.alert) {
// do your normal thing
}
else {
postMessage("no support for this");
}
Web Workers Allow You to Run JavaScript Code in the Background. Web workers can't call alert() or confirm() functions.