It seems the only communication from host to worker is postMessgage and onmessage. If the worker requires some dynamic initialization (as in constructor, here: regular expression to use later), what is the best way to do this?
A possibility would be to let data be an object, and have e.g. an action parameter, and to check this on every run. This seems a bit kludgey.
The communication channel between different agents is very low-level, but you can easily build a higher level communication based on that. I'd use objects to communicate different "events":
{ event: "init", data: [/d/] }
Based on these events, you can create different events to represent e.g. function calls and their response:
{ event: "call-init", data: [/d/] } // >>>
{ event: "return-init", data: ["done"] } // <<<
Then you can build a wrapper around that, that sends and handles the response, something like:
async function call(name, ...args) {
channel.send("call-" + name, args);
return await cannel.once("return-" + name);
}
channel.init = call.bind(null, "init");
Then your code turns into something along the lines of:
const channel = new Channel(worker);
await channel.init(/d/);
await channel.doOtherStuff();
That's just to give you the basic idea.
A more ad-hoc approach than Jonas' solution abuses the Worker's name option: You can e.g. pass the regex string in this name and use it later:
test.js
var a = new Worker("worker.js", {name: "hello|world"})
a.onmessage = (x) => {
console.log("worker sent: ")
console.log(x)
}
a.postMessage("hello")
worker.js
var regex = RegExp(this.name);
onmessage = (a) => {
if (regex.test(a.data)) {
postMessage("matches");
} else {
postMessage("no match for " + regex);
}
}