⚠️
This function is part of the internal API. It is intended for developers creating their own frameworks. It is not recommended for general use.
mapArray()
Syntax: mapArray(Block[])
Example: mapArray([block, block, block])
The mapArray function is used to create a Block list. It's the best way to render a view that's derived from array-like data. As the array changes, mapArray() updates or moves items in the DOM rather than recreating them. Let's look at an example:
import { block, patch, mapArray } from 'million';
const oldList = [1, 2, 3];
const newList = [3, 2, 1];
const list = block(({ item }) => {
return <div>{item}</div>;
});
// updates list efficiently (only 2 moves instead of 3 updates)
patch(
document.body,
mapArray(oldList.map((item) => list({ item }))),
mapArray(newList.map((item) => list({ item }))),
);