javascript - Process message from Webworker created by unreachable code -

i'm new javascript, i'm sorry if answer obvious.

i want send message main thread web-worker. don't have access part of code create worker can't add worker.onmessage = [...]. have access javascript code executed @ begining of process, not 1 create workers.

i wondering if there's way window.oneverymessagefromanyworker = dosomemagic()

thanks lot!

no, that's not possible. need handle web worker in order listen messages. make sure can't change code makes worker, if you can't read below:

hacky solution

if you're writing userscript or other "hacky" code, suggest override worker constructor:

// execute before worker being created window.oldworker = worker; window.worker = function(path) {     console.log("worker created: ", path);     // original worker applied on object     return new oldworker(path); } 

note nasty piece of code. might break things.

once have code, can access worker created:

window.worker = function(path) {     console.log("worker created: ", path);     var worker = new oldworker(path);     if(path == "something.js") {         //         worker.addeventlistener("message", (e)=>{console.log("message:", e.data});     }     // original worker applied on object     return worker; } 

note must use worker.addeventlistener. setting .onmessage can cause callback overridden, since there can 1 callback in onmessage property.