Iterate an array in an asynchronous manner.
npm install @chriscdn/async-eachIterate an array in an asynchronous manner with a progress callback function.
Iterating a large array can block the event loop if the block doesn't include asynchronous code. This can cause the user interface to become unresponsive.
This module provides a method for iterating an array in an asynchronous manner, which helps minimise the risk of blocking the event loop. It also provides a status callback to report the progress of the iteration. This can be useful for providing feedback to the user on the state of a process.
The function returns a Promise, which resolves to an array with the return values.
``js`
const results = await asyncEach(array, callbackFn, statusCallbackFn);
- array
- The array to iterate.
-
- A function to execute on each element of the array. The function can return a promise, and the resolved value is aggregated into . The function is called with the following arguments:item
- - The current item being processed in the array.index
- - The index of the item being processed in the array.items
- - The array being processed.statusCallbackFn
-
- An optional callback function to execute on the completion of an iteration. The function takes one argument, which is an object containing the following properties:
- - The total number of items that have been processed.total
- - The length of the array being processed.percent
- - The number of items processed, as a percentage of the total number of items to process. This is simply Math.floor((100 * progress) / total).item
- - The item of the array that was just completed.index
- - The index of the item of the array that was just completed.result
- - The resolved return value of the callback function on the item.
The following example squares an array of integers.
`js
import asyncEach from "@chriscdn/async-each";
const results = await asyncEach(
[1, 2, 3],
(item, index, items) => item * item,
(status) => {
// status can be used to show a progress indicator to the user
console.log(status);
}
);
console.log(results);
// [1, 4, 9];
``