Definitely something to know, but it's the best way for that to happen when you're waiting on asynchronous requests, as it lets you create the subsequent promises while the first promises is fetching its results
If you don't want to continue with something inside a Promise, just pass in something that could be changed from `true` to `false` and it cancels itself based on that.
Regarding other cases, there are already ways of handling those. I don't think just because many ask about something, doesn't mean it's not currently working.
controller = new AbortController();
const signal = controller.signal;
fetch("http://example.com", { signal: signal })
// abort request
controller.abort();
Here is the implementation I typically use for doing just that:
async function executeQueue(promises, concurrentLimit) {
let index = 0;
let activePromises = [];
async function manageQueue() {
if (index >= promises.length && activePromises.length === 0) return;
while (activePromises.length < concurrentLimit && index < promises.length) {
const promise = promises[index]();
activePromises.push(promise);
index++;
promise.then(() => {
activePromises = activePromises.filter(p => p !== promise);
manageQueue();
});
}
}
await manageQueue();
await Promise.all(activePromises);
}
function r(i, resolve) {
console.log(`Task ${i}`)
resolve(`Task ${resolve}`)
}
// Example usage
const promises = [
() => new Promise(resolve => setTimeout(() => r("Task 1", resolve), 2000)),
() => new Promise(resolve => setTimeout(() => r("Task 2", resolve), 1000)),
() => new Promise(resolve => setTimeout(() => r("Task 3", resolve), 3000)),
() => new Promise(resolve => setTimeout(() => r("Task 4", resolve), 500)),
() => new Promise(resolve => setTimeout(() => r("Task 5", resolve), 1500))
];
executeQueue(promises, 4).then(() => {
console.log("All tasks completed!");
});
"Task Task 4"
"Task Task 2"
"Task Task 1"
"Task Task 5"
"Task Task 3"
"All tasks completed!"